Clone Nyquist keyboard for Viterbi

15 files changed, 1389 insertions, 0 deletions

diff --git a/keyboards/viterbi/Makefile b/keyboards/viterbi/Makefile
new file mode 100644
index 000000000..0c519b323
--- /dev/null
+++ b/keyboards/viterbi/Makefile
@@ -0,0 +1,5 @@
+SUBPROJECT_DEFAULT = rev1
+
+ifndef MAKEFILE_INCLUDED
+        include ../../Makefile
+endif
diff --git a/keyboards/viterbi/config.h b/keyboards/viterbi/config.h
new file mode 100644
index 000000000..55500df79
--- /dev/null
+++ b/keyboards/viterbi/config.h
@@ -0,0 +1,27 @@
+/*
+Copyright 2017 Danny Nguyen <danny@hexwire.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include "config_common.h"
+
+#ifdef SUBPROJECT_rev1
+    #include "rev1/config.h"
+#endif
+
+#endif  // CONFIG_H
diff --git a/keyboards/viterbi/i2c.c b/keyboards/viterbi/i2c.c
new file mode 100644
index 000000000..084c890c4
--- /dev/null
+++ b/keyboards/viterbi/i2c.c
@@ -0,0 +1,162 @@
+#include <util/twi.h>
+#include <avr/io.h>
+#include <stdlib.h>
+#include <avr/interrupt.h>
+#include <util/twi.h>
+#include <stdbool.h>
+#include "i2c.h"
+
+#ifdef USE_I2C
+
+// Limits the amount of we wait for any one i2c transaction.
+// Since were running SCL line 100kHz (=> 10μs/bit), and each transactions is
+// 9 bits, a single transaction will take around 90μs to complete.
+//
+// (F_CPU/SCL_CLOCK)  =>  # of μC cycles to transfer a bit
+// poll loop takes at least 8 clock cycles to execute
+#define I2C_LOOP_TIMEOUT (9+1)*(F_CPU/SCL_CLOCK)/8
+
+#define BUFFER_POS_INC() (slave_buffer_pos = (slave_buffer_pos+1)%SLAVE_BUFFER_SIZE)
+
+volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
+
+static volatile uint8_t slave_buffer_pos;
+static volatile bool slave_has_register_set = false;
+
+// Wait for an i2c operation to finish
+inline static
+void i2c_delay(void) {
+  uint16_t lim = 0;
+  while(!(TWCR & (1<<TWINT)) && lim < I2C_LOOP_TIMEOUT)
+    lim++;
+
+  // easier way, but will wait slightly longer
+  // _delay_us(100);
+}
+
+// Setup twi to run at 100kHz
+void i2c_master_init(void) {
+  // no prescaler
+  TWSR = 0;
+  // Set TWI clock frequency to SCL_CLOCK. Need TWBR>10.
+  // Check datasheets for more info.
+  TWBR = ((F_CPU/SCL_CLOCK)-16)/2;
+}
+
+// Start a transaction with the given i2c slave address. The direction of the
+// transfer is set with I2C_READ and I2C_WRITE.
+// returns: 0 => success
+//          1 => error
+uint8_t i2c_master_start(uint8_t address) {
+  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTA);
+
+  i2c_delay();
+
+  // check that we started successfully
+  if ( (TW_STATUS != TW_START) && (TW_STATUS != TW_REP_START))
+    return 1;
+
+  TWDR = address;
+  TWCR = (1<<TWINT) | (1<<TWEN);
+
+  i2c_delay();
+
+  if ( (TW_STATUS != TW_MT_SLA_ACK) && (TW_STATUS != TW_MR_SLA_ACK) )
+    return 1; // slave did not acknowledge
+  else
+    return 0; // success
+}
+
+
+// Finish the i2c transaction.
+void i2c_master_stop(void) {
+  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
+
+  uint16_t lim = 0;
+  while(!(TWCR & (1<<TWSTO)) && lim < I2C_LOOP_TIMEOUT)
+    lim++;
+}
+
+// Write one byte to the i2c slave.
+// returns 0 => slave ACK
+//         1 => slave NACK
+uint8_t i2c_master_write(uint8_t data) {
+  TWDR = data;
+  TWCR = (1<<TWINT) | (1<<TWEN);
+
+  i2c_delay();
+
+  // check if the slave acknowledged us
+  return (TW_STATUS == TW_MT_DATA_ACK) ? 0 : 1;
+}
+
+// Read one byte from the i2c slave. If ack=1 the slave is acknowledged,
+// if ack=0 the acknowledge bit is not set.
+// returns: byte read from i2c device
+uint8_t i2c_master_read(int ack) {
+  TWCR = (1<<TWINT) | (1<<TWEN) | (ack<<TWEA);
+
+  i2c_delay();
+  return TWDR;
+}
+
+void i2c_reset_state(void) {
+  TWCR = 0;
+}
+
+void i2c_slave_init(uint8_t address) {
+  TWAR = address << 0; // slave i2c address
+  // TWEN  - twi enable
+  // TWEA  - enable address acknowledgement
+  // TWINT - twi interrupt flag
+  // TWIE  - enable the twi interrupt
+  TWCR = (1<<TWIE) | (1<<TWEA) | (1<<TWINT) | (1<<TWEN);
+}
+
+ISR(TWI_vect);
+
+ISR(TWI_vect) {
+  uint8_t ack = 1;
+  switch(TW_STATUS) {
+    case TW_SR_SLA_ACK:
+      // this device has been addressed as a slave receiver
+      slave_has_register_set = false;
+      break;
+
+    case TW_SR_DATA_ACK:
+      // this device has received data as a slave receiver
+      // The first byte that we receive in this transaction sets the location
+      // of the read/write location of the slaves memory that it exposes over
+      // i2c.  After that, bytes will be written at slave_buffer_pos, incrementing
+      // slave_buffer_pos after each write.
+      if(!slave_has_register_set) {
+        slave_buffer_pos = TWDR;
+        // don't acknowledge the master if this memory loctaion is out of bounds
+        if ( slave_buffer_pos >= SLAVE_BUFFER_SIZE ) {
+          ack = 0;
+          slave_buffer_pos = 0;
+        }
+        slave_has_register_set = true;
+      } else {
+        i2c_slave_buffer[slave_buffer_pos] = TWDR;
+        BUFFER_POS_INC();
+      }
+      break;
+
+    case TW_ST_SLA_ACK:
+    case TW_ST_DATA_ACK:
+      // master has addressed this device as a slave transmitter and is
+      // requesting data.
+      TWDR = i2c_slave_buffer[slave_buffer_pos];
+      BUFFER_POS_INC();
+      break;
+
+    case TW_BUS_ERROR: // something went wrong, reset twi state
+      TWCR = 0;
+    default:
+      break;
+  }
+  // Reset everything, so we are ready for the next TWI interrupt
+  TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN);
+}
+#endif
diff --git a/keyboards/viterbi/i2c.h b/keyboards/viterbi/i2c.h
new file mode 100644
index 000000000..43e596988
--- /dev/null
+++ b/keyboards/viterbi/i2c.h
@@ -0,0 +1,49 @@
+#ifndef I2C_H
+#define I2C_H
+
+#include <stdint.h>
+
+#ifndef F_CPU
+#define F_CPU 16000000UL
+#endif
+
+#define I2C_READ 1
+#define I2C_WRITE 0
+
+#define I2C_ACK 1
+#define I2C_NACK 0
+
+#define SLAVE_BUFFER_SIZE 0x10
+
+// i2c SCL clock frequency
+#define SCL_CLOCK  100000L
+
+extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
+
+void i2c_master_init(void);
+uint8_t i2c_master_start(uint8_t address);
+void i2c_master_stop(void);
+uint8_t i2c_master_write(uint8_t data);
+uint8_t i2c_master_read(int);
+void i2c_reset_state(void);
+void i2c_slave_init(uint8_t address);
+
+
+static inline unsigned char i2c_start_read(unsigned char addr) {
+  return i2c_master_start((addr << 1) | I2C_READ);
+}
+
+static inline unsigned char i2c_start_write(unsigned char addr) {
+  return i2c_master_start((addr << 1) | I2C_WRITE);
+}
+
+// from SSD1306 scrips
+extern unsigned char i2c_rep_start(unsigned char addr);
+extern void i2c_start_wait(unsigned char addr);
+extern unsigned char i2c_readAck(void);
+extern unsigned char i2c_readNak(void);
+extern unsigned char i2c_read(unsigned char ack);
+
+#define i2c_read(ack)  (ack) ? i2c_readAck() : i2c_readNak();
+
+#endif
diff --git a/keyboards/viterbi/matrix.c b/keyboards/viterbi/matrix.c
new file mode 100644
index 000000000..21eef9456
--- /dev/null
+++ b/keyboards/viterbi/matrix.c
@@ -0,0 +1,464 @@
+/*
+Copyright 2017 Danny Nguyen <danny@hexwire.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * scan matrix
+ */
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/io.h>
+#include "wait.h"
+#include "print.h"
+#include "debug.h"
+#include "util.h"
+#include "matrix.h"
+#include "split_util.h"
+#include "pro_micro.h"
+#include "config.h"
+#include "timer.h"
+
+#ifdef USE_I2C
+#  include "i2c.h"
+#else // USE_SERIAL
+#  include "serial.h"
+#endif
+
+#ifndef DEBOUNCING_DELAY
+#   define DEBOUNCING_DELAY 5
+#endif
+
+#if (DEBOUNCING_DELAY > 0)
+    static uint16_t debouncing_time;
+    static bool debouncing = false;
+#endif
+
+#if (MATRIX_COLS <= 8)
+#    define print_matrix_header()  print("\nr/c 01234567\n")
+#    define print_matrix_row(row)  print_bin_reverse8(matrix_get_row(row))
+#    define matrix_bitpop(i)       bitpop(matrix[i])
+#    define ROW_SHIFTER ((uint8_t)1)
+#else
+#    error "Currently only supports 8 COLS"
+#endif
+static matrix_row_t matrix_debouncing[MATRIX_ROWS];
+
+#define ERROR_DISCONNECT_COUNT 5
+
+#define ROWS_PER_HAND (MATRIX_ROWS/2)
+
+static uint8_t error_count = 0;
+
+static const uint8_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
+static const uint8_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
+
+/* matrix state(1:on, 0:off) */
+static matrix_row_t matrix[MATRIX_ROWS];
+static matrix_row_t matrix_debouncing[MATRIX_ROWS];
+
+#if (DIODE_DIRECTION == COL2ROW)
+    static void init_cols(void);
+    static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row);
+    static void unselect_rows(void);
+    static void select_row(uint8_t row);
+    static void unselect_row(uint8_t row);
+#elif (DIODE_DIRECTION == ROW2COL)
+    static void init_rows(void);
+    static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col);
+    static void unselect_cols(void);
+    static void unselect_col(uint8_t col);
+    static void select_col(uint8_t col);
+#endif
+__attribute__ ((weak))
+void matrix_init_quantum(void) {
+    matrix_init_kb();
+}
+
+__attribute__ ((weak))
+void matrix_scan_quantum(void) {
+    matrix_scan_kb();
+}
+
+__attribute__ ((weak))
+void matrix_init_kb(void) {
+    matrix_init_user();
+}
+
+__attribute__ ((weak))
+void matrix_scan_kb(void) {
+    matrix_scan_user();
+}
+
+__attribute__ ((weak))
+void matrix_init_user(void) {
+}
+
+__attribute__ ((weak))
+void matrix_scan_user(void) {
+}
+
+inline
+uint8_t matrix_rows(void)
+{
+    return MATRIX_ROWS;
+}
+
+inline
+uint8_t matrix_cols(void)
+{
+    return MATRIX_COLS;
+}
+
+void matrix_init(void)
+{
+    debug_enable = true;
+    debug_matrix = true;
+    debug_mouse = true;
+    // initialize row and col
+    unselect_rows();
+    init_cols();
+
+    TX_RX_LED_INIT;
+
+    // initialize matrix state: all keys off
+    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
+        matrix[i] = 0;
+        matrix_debouncing[i] = 0;
+    }
+
+    matrix_init_quantum();
+
+}
+
+uint8_t _matrix_scan(void)
+{
+    int offset = isLeftHand ? 0 : (ROWS_PER_HAND);
+#if (DIODE_DIRECTION == COL2ROW)
+    // Set row, read cols
+    for (uint8_t current_row = 0; current_row < ROWS_PER_HAND; current_row++) {
+#       if (DEBOUNCING_DELAY > 0)
+            bool matrix_changed = read_cols_on_row(matrix_debouncing+offset, current_row);
+
+            if (matrix_changed) {
+                debouncing = true;
+                debouncing_time = timer_read();
+                PORTD ^= (1 << 2);
+            }
+
+#       else
+            read_cols_on_row(matrix+offset, current_row);
+#       endif
+
+    }
+
+#elif (DIODE_DIRECTION == ROW2COL)
+    // Set col, read rows
+    for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
+#       if (DEBOUNCING_DELAY > 0)
+            bool matrix_changed = read_rows_on_col(matrix_debouncing+offset, current_col);
+            if (matrix_changed) {
+                debouncing = true;
+                debouncing_time = timer_read();
+            }
+#       else
+             read_rows_on_col(matrix+offset, current_col);
+#       endif
+
+    }
+#endif
+
+#   if (DEBOUNCING_DELAY > 0)
+        if (debouncing && (timer_elapsed(debouncing_time) > DEBOUNCING_DELAY)) {
+            for (uint8_t i = 0; i < ROWS_PER_HAND; i++) {
+                matrix[i+offset] = matrix_debouncing[i+offset];
+            }
+            debouncing = false;
+        }
+#   endif
+
+    return 1;
+}
+
+#ifdef USE_I2C
+
+// Get rows from other half over i2c
+int i2c_transaction(void) {
+    int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
+
+    int err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
+    if (err) goto i2c_error;
+
+    // start of matrix stored at 0x00
+    err = i2c_master_write(0x00);
+    if (err) goto i2c_error;
+
+    // Start read
+    err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_READ);
+    if (err) goto i2c_error;
+
+    if (!err) {
+        int i;
+        for (i = 0; i < ROWS_PER_HAND-1; ++i) {
+            matrix[slaveOffset+i] = i2c_master_read(I2C_ACK);
+        }
+        matrix[slaveOffset+i] = i2c_master_read(I2C_NACK);
+        i2c_master_stop();
+    } else {
+i2c_error: // the cable is disconnceted, or something else went wrong
+        i2c_reset_state();
+        return err;
+    }
+
+    return 0;
+}
+
+#else // USE_SERIAL
+
+int serial_transaction(void) {
+    int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
+
+    if (serial_update_buffers()) {
+        return 1;
+    }
+
+    for (int i = 0; i < ROWS_PER_HAND; ++i) {
+        matrix[slaveOffset+i] = serial_slave_buffer[i];
+    }
+    return 0;
+}
+#endif
+
+uint8_t matrix_scan(void)
+{
+    uint8_t ret = _matrix_scan();
+
+#ifdef USE_I2C
+    if( i2c_transaction() ) {
+#else // USE_SERIAL
+    if( serial_transaction() ) {
+#endif
+        // turn on the indicator led when halves are disconnected
+        TXLED1;
+
+        error_count++;
+
+        if (error_count > ERROR_DISCONNECT_COUNT) {
+            // reset other half if disconnected
+            int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
+            for (int i = 0; i < ROWS_PER_HAND; ++i) {
+                matrix[slaveOffset+i] = 0;
+            }
+        }
+    } else {
+        // turn off the indicator led on no error
+        TXLED0;
+        error_count = 0;
+    }
+    matrix_scan_quantum();
+    return ret;
+}
+
+void matrix_slave_scan(void) {
+    _matrix_scan();
+
+    int offset = (isLeftHand) ? 0 : ROWS_PER_HAND;
+
+#ifdef USE_I2C
+    for (int i = 0; i < ROWS_PER_HAND; ++i) {
+        i2c_slave_buffer[i] = matrix[offset+i];
+    }
+#else // USE_SERIAL
+    for (int i = 0; i < ROWS_PER_HAND; ++i) {
+        serial_slave_buffer[i] = matrix[offset+i];
+    }
+#endif
+}
+
+bool matrix_is_modified(void)
+{
+    if (debouncing) return false;
+    return true;
+}
+
+inline
+bool matrix_is_on(uint8_t row, uint8_t col)
+{
+    return (matrix[row] & ((matrix_row_t)1<<col));
+}
+
+inline
+matrix_row_t matrix_get_row(uint8_t row)
+{
+    return matrix[row];
+}
+
+void matrix_print(void)
+{
+    print("\nr/c 0123456789ABCDEF\n");
+    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
+        phex(row); print(": ");
+        pbin_reverse16(matrix_get_row(row));
+        print("\n");
+    }
+}
+
+uint8_t matrix_key_count(void)
+{
+    uint8_t count = 0;
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+        count += bitpop16(matrix[i]);
+    }
+    return count;
+}
+
+#if (DIODE_DIRECTION == COL2ROW)
+
+static void init_cols(void)
+{
+    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
+        uint8_t pin = col_pins[x];
+        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
+        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
+    }
+}
+
+static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row)
+{
+    // Store last value of row prior to reading
+    matrix_row_t last_row_value = current_matrix[current_row];
+
+    // Clear data in matrix row
+    current_matrix[current_row] = 0;
+
+    // Select row and wait for row selecton to stabilize
+    select_row(current_row);
+    wait_us(30);
+
+    // For each col...
+    for(uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
+
+        // Select the col pin to read (active low)
+        uint8_t pin = col_pins[col_index];
+        uint8_t pin_state = (_SFR_IO8(pin >> 4) & _BV(pin & 0xF));
+
+        // Populate the matrix row with the state of the col pin
+        current_matrix[current_row] |=  pin_state ? 0 : (ROW_SHIFTER << col_index);
+    }
+
+    // Unselect row
+    unselect_row(current_row);
+
+    return (last_row_value != current_matrix[current_row]);
+}
+
+static void select_row(uint8_t row)
+{
+    uint8_t pin = row_pins[row];
+    _SFR_IO8((pin >> 4) + 1) |=  _BV(pin & 0xF); // OUT
+    _SFR_IO8((pin >> 4) + 2) &= ~_BV(pin & 0xF); // LOW
+}
+
+static void unselect_row(uint8_t row)
+{
+    uint8_t pin = row_pins[row];
+    _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
+    _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
+}
+
+static void unselect_rows(void)
+{
+    for(uint8_t x = 0; x < ROWS_PER_HAND; x++) {
+        uint8_t pin = row_pins[x];
+        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
+        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
+    }
+}
+
+#elif (DIODE_DIRECTION == ROW2COL)
+
+static void init_rows(void)
+{
+    for(uint8_t x = 0; x < ROWS_PER_HAND; x++) {
+        uint8_t pin = row_pins[x];
+        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
+        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
+    }
+}
+
+static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
+{
+    bool matrix_changed = false;
+
+    // Select col and wait for col selecton to stabilize
+    select_col(current_col);
+    wait_us(30);
+
+    // For each row...
+    for(uint8_t row_index = 0; row_index < ROWS_PER_HAND; row_index++)
+    {
+
+        // Store last value of row prior to reading
+        matrix_row_t last_row_value = current_matrix[row_index];
+
+        // Check row pin state
+        if ((_SFR_IO8(row_pins[row_index] >> 4) & _BV(row_pins[row_index] & 0xF)) == 0)
+        {
+            // Pin LO, set col bit
+            current_matrix[row_index] |= (ROW_SHIFTER << current_col);
+        }
+        else
+        {
+            // Pin HI, clear col bit
+            current_matrix[row_index] &= ~(ROW_SHIFTER << current_col);
+        }
+
+        // Determine if the matrix changed state
+        if ((last_row_value != current_matrix[row_index]) && !(matrix_changed))
+        {
+            matrix_changed = true;
+        }
+    }
+
+    // Unselect col
+    unselect_col(current_col);
+
+    return matrix_changed;
+}
+
+static void select_col(uint8_t col)
+{
+    uint8_t pin = col_pins[col];
+    _SFR_IO8((pin >> 4) + 1) |=  _BV(pin & 0xF); // OUT
+    _SFR_IO8((pin >> 4) + 2) &= ~_BV(pin & 0xF); // LOW
+}
+
+static void unselect_col(uint8_t col)
+{
+    uint8_t pin = col_pins[col];
+    _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
+    _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
+}
+
+static void unselect_cols(void)
+{
+    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
+        uint8_t pin = col_pins[x];
+        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
+        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
+    }
+}
+
+#endif
diff --git a/keyboards/viterbi/nyquist.c b/keyboards/viterbi/nyquist.c
new file mode 100644
index 000000000..2face09d4
--- /dev/null
+++ b/keyboards/viterbi/nyquist.c
@@ -0,0 +1 @@
+#include "nyquist.h"
diff --git a/keyboards/viterbi/nyquist.h b/keyboards/viterbi/nyquist.h
new file mode 100644
index 000000000..e8cccecf5
--- /dev/null
+++ b/keyboards/viterbi/nyquist.h
@@ -0,0 +1,26 @@
+#ifndef NYQUIST_H
+#define NYQUIST_H
+
+#ifdef SUBPROJECT_rev1
+    #include "rev1.h"
+#endif
+
+// Used to create a keymap using only KC_ prefixed keys
+#define KC_KEYMAP( \
+    L00, L01, L02, L03, L04, L05, R00, R01, R02, R03, R04, R05, \
+    L10, L11, L12, L13, L14, L15, R10, R11, R12, R13, R14, R15, \
+    L20, L21, L22, L23, L24, L25, R20, R21, R22, R23, R24, R25, \
+    L30, L31, L32, L33, L34, L35, R30, R31, R32, R33, R34, R35, \
+    L40, L41, L42, L43, L44, L45, R40, R41, R42, R43, R44, R45 \
+    ) \
+    KEYMAP( \
+        KC_##L00, KC_##L01, KC_##L02, KC_##L03, KC_##L04, KC_##L05, KC_##R00, KC_##R01, KC_##R02, KC_##R03, KC_##R04, KC_##R05, \
+        KC_##L10, KC_##L11, KC_##L12, KC_##L13, KC_##L14, KC_##L15, KC_##R10, KC_##R11, KC_##R12, KC_##R13, KC_##R14, KC_##R15, \
+        KC_##L20, KC_##L21, KC_##L22, KC_##L23, KC_##L24, KC_##L25, KC_##R20, KC_##R21, KC_##R22, KC_##R23, KC_##R24, KC_##R25, \
+        KC_##L30, KC_##L31, KC_##L32, KC_##L33, KC_##L34, KC_##L35, KC_##R30, KC_##R31, KC_##R32, KC_##R33, KC_##R34, KC_##R35, \
+        KC_##L40, KC_##L41, KC_##L42, KC_##L43, KC_##L44, KC_##L45, KC_##R40, KC_##R41, KC_##R42, KC_##R43, KC_##R44, KC_##R45 \
+    )
+
+#include "quantum.h"
+
+#endif
\ No newline at end of file
diff --git a/keyboards/viterbi/readme.md b/keyboards/viterbi/readme.md
new file mode 100644
index 000000000..61b9317d5
--- /dev/null
+++ b/keyboards/viterbi/readme.md
@@ -0,0 +1,169 @@
+The Nyquist Keyboard
+====================
+
+The Nyquist is a 60% split ortholinear board by [Keebio](https://keeb.io). It has been designed in a similar manner to the Let's Split v2 by /u/wootpatoot. Each half of the keyboard is arranged in a 5x6 grid. There is an option to use a 2u key with PCB mounted MX stablizers, in place of the two innermost 1u keys on the bottom row.
+
+
+## Build Guide
+
+A build log of the Nyquist can be found here: [Nyquist Build Log](http://imgur.com/a/dD4sX).
+
+Since the design is very similar to the Let's Split v2, the build guide for that can be used while the build guide for the Nyquist is being fully developed. A build guide for putting together the Let's Split v2 can be found here: [An Overly Verbose Guide to Building a Let's Split Keyboard](https://github.com/nicinabox/lets-split-guide)
+
+There is additional information there about flashing and adding RGB underglow.
+
+## First Time Setup
+
+Download or clone the whole firmware and navigate to the keyboards/nyquist directory. Once your development environment is setup, you'll be able to generate the default .hex using:
+
+```
+$ make serial
+```
+
+You will see a lot of output and if everything worked correctly you will see the built hex file:
+
+```
+nyquist_rev1_serial.hex
+```
+
+If you would like to use one of the alternative keymaps, or create your own, copy one of the existing [keymaps](keymaps/) and run make like so:
+
+
+```
+$ make YOUR_KEYMAP_NAME
+```
+
+If everything worked correctly you will see a file:
+
+```
+nyquist_rev1_YOUR_KEYMAP_NAME.hex
+```
+
+For more information on customizing keymaps, take a look at the primary documentation for [Customizing Your Keymap](/readme.md##customizing-your-keymap) in the main readme.md.
+
+Features
+--------
+
+For the full Quantum Mechanical Keyboard feature list, see [the parent readme.md](/readme.md).
+
+Some features supported by the firmware:
+
+* Either half can connect to the computer via USB, or both halves can be used
+  independently.
+* You only need 3 wires to connect the two halves. Two for VCC and GND and one
+  for serial communication.
+* Optional support for I2C connection between the two halves if for some
+  reason you require a faster connection between the two halves. Note this
+  requires an extra wire between halves and pull-up resistors on the data lines.
+
+### 2u Support
+In place of the two innermost 1u keys on the bottom row, a single 2u key can be used. If you choose to use this option, then in your keymap, set the innermost key on the bottom row to what you want the 2u key to be. For example, if using the 2u key on the left half of the board, set the keycode for the lower right key.
+
+Required Hardware
+-----------------
+
+Apart from diodes and key switches for the keyboard matrix in each half, you
+will need:
+
+* 2 Arduino Pro Micro's. You can find theses on aliexpress for ≈3.50USD each.
+* 2 TRRS sockets and 1 TRRS cable, or 2 TRS sockets and 1 TRS cable
+
+Alternatively, you can use any sort of cable and socket that has at least 3
+wires. If you want to use I2C to communicate between halves, you will need a
+cable with at least 4 wires and 2x 4.7kΩ pull-up resistors
+
+Optional Hardware
+-----------------
+
+A speaker can be hooked-up to either side to the `5` (`C6`) pin and `GND`, and turned on via `AUDIO_ENABLE`.
+
+Wiring
+------
+
+The 3 wires of the TRS/TRRS cable need to connect GND, VCC, and digital pin 3 (i.e.
+PD0 on the ATmega32u4) between the two Pro Micros.
+
+Then wire your key matrix to any of the remaining 17 IO pins of the pro micro
+and modify the `matrix.c` accordingly.
+
+The wiring for serial:
+
+![serial wiring](http://imgur.com/BnCGU1Y)
+
+The wiring for i2c:
+
+![i2c wiring](http://imgur.com/5eiArDA)
+
+The pull-up resistors may be placed on either half. It is also possible
+to use 4 resistors and have the pull-ups in both halves, but this is
+unnecessary in simple use cases.
+
+Flashing
+-------
+From the `nyquist` directory run `make SUBPROJECT-KEYMAP-avrdude` for automatic serial port resolution and flashing.
+Example: `make rev1-serial-avrdude`
+
+
+Choosing which board to plug the USB cable into (choosing Master)
+--------
+Because the two boards are identical, the firmware has logic to differentiate the left and right board.
+
+It uses two strategies to figure things out: look at the EEPROM (memory on the chip) or looks if the current board has the usb cable.
+
+The EEPROM approach requires additional setup (flashing the eeeprom) but allows you to swap the usb cable to either side.
+
+The USB cable approach is easier to setup and if you just want the usb cable on the left board, you do not need to do anything extra.
+
+### Setting the left hand as master
+If you always plug the usb cable into the left board, nothing extra is needed as this is the default. Comment out `EE_HANDS` and comment out `I2C_MASTER_RIGHT` or `MASTER_RIGHT` if for some reason it was set.
+
+### Setting the right hand as master
+If you always plug the usb cable into the right board, add an extra flag to your `config.h`
+```
+ #define MASTER_RIGHT
+```
+
+### Setting EE_hands to use either hands as master
+If you define `EE_HANDS` in your `config.h`, you will need to set the
+EEPROM for the left and right halves.
+
+The EEPROM is used to store whether the
+half is left handed or right handed. This makes it so that the same firmware
+file will run on both hands instead of having to flash left and right handed
+versions of the firmware to each half. To flash the EEPROM file for the left
+half run:
+```
+avrdude -p atmega32u4 -P $(COM_PORT) -c avr109 -U eeprom:w:eeprom-lefthand.eep
+// or the equivalent in dfu-programmer
+
+```
+and similarly for right half
+```
+avrdude -p atmega32u4 -P $(COM_PORT) -c avr109 -U eeprom:w:eeprom-righhand.eep
+// or the equivalent in dfu-programmer
+```
+
+NOTE: replace `$(COM_PORT)` with the port of your device (e.g. `/dev/ttyACM0`)
+
+After you have flashed the EEPROM, you then need to set `EE_HANDS` in your config.h, rebuild the hex files and reflash.
+
+Note that you need to program both halves, but you have the option of using
+different keymaps for each half. You could program the left half with a QWERTY
+layout and the right half with a Colemak layout using bootmagic's default layout option.
+Then if you connect the left half to a computer by USB the keyboard will use QWERTY and Colemak when the
+right half is connected.
+
+
+Notes on Using Pro Micro 3.3V
+-----------------------------
+
+Do update the `F_CPU` parameter in `rules.mk` to `8000000` which reflects
+the frequency on the 3.3V board.
+
+Also, if the slave board is producing weird characters in certain columns,
+update the following line in `matrix.c` to the following:
+
+```
+// _delay_us(30);  // without this wait read unstable value.
+_delay_us(300);  // without this wait read unstable value.
+```
diff --git a/keyboards/viterbi/rules.mk b/keyboards/viterbi/rules.mk
new file mode 100644
index 000000000..3f40ff2f8
--- /dev/null
+++ b/keyboards/viterbi/rules.mk
@@ -0,0 +1,75 @@
+SRC += matrix.c \
+           i2c.c \
+           split_util.c \
+           serial.c
+
+# MCU name
+#MCU = at90usb1287
+MCU = atmega32u4
+
+# Processor frequency.
+#     This will define a symbol, F_CPU, in all source code files equal to the
+#     processor frequency in Hz. You can then use this symbol in your source code to
+#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
+#     automatically to create a 32-bit value in your source code.
+#
+#     This will be an integer division of F_USB below, as it is sourced by
+#     F_USB after it has run through any CPU prescalers. Note that this value
+#     does not *change* the processor frequency - it should merely be updated to
+#     reflect the processor speed set externally so that the code can use accurate
+#     software delays.
+F_CPU = 16000000
+
+#
+# LUFA specific
+#
+# Target architecture (see library "Board Types" documentation).
+ARCH = AVR8
+
+# Input clock frequency.
+#     This will define a symbol, F_USB, in all source code files equal to the
+#     input clock frequency (before any prescaling is performed) in Hz. This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_USB = $(F_CPU)
+
+# Interrupt driven control endpoint task(+60)
+OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
+
+
+# Boot Section Size in *bytes*
+#   Teensy halfKay   512
+#   Teensy++ halfKay 1024
+#   Atmel DFU loader 4096
+#   LUFA bootloader  4096
+#   USBaspLoader     2048
+OPT_DEFS += -DBOOTLOADER_SIZE=4096
+
+# Build Options
+#   change to "no" to disable the options, or define them in the Makefile in
+#   the appropriate keymap folder that will get included automatically
+#
+BOOTMAGIC_ENABLE = no       # Virtual DIP switch configuration(+1000)
+MOUSEKEY_ENABLE = yes       # Mouse keys(+4700)
+EXTRAKEY_ENABLE = yes       # Audio control and System control(+450)
+CONSOLE_ENABLE = no         # Console for debug(+400)
+COMMAND_ENABLE = yes        # Commands for debug and configuration
+NKRO_ENABLE = no            # Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
+BACKLIGHT_ENABLE = no      # Enable keyboard backlight functionality
+MIDI_ENABLE = no            # MIDI controls
+AUDIO_ENABLE = no           # Audio output on port C6
+UNICODE_ENABLE = no         # Unicode
+BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
+RGBLIGHT_ENABLE = no       # Enable WS2812 RGB underlight.  Do not enable this with audio at the same time.
+SUBPROJECT_rev1 = yes
+USE_I2C = yes
+# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
+SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
+
+CUSTOM_MATRIX = yes
diff --git a/keyboards/viterbi/serial.c b/keyboards/viterbi/serial.c
new file mode 100644
index 000000000..6faed09ce
--- /dev/null
+++ b/keyboards/viterbi/serial.c
@@ -0,0 +1,228 @@
+/*
+ * WARNING: be careful changing this code, it is very timing dependent
+ */
+
+#ifndef F_CPU
+#define F_CPU 16000000
+#endif
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <stdbool.h>
+#include "serial.h"
+
+#ifdef USE_SERIAL
+
+// Serial pulse period in microseconds. Its probably a bad idea to lower this
+// value.
+#define SERIAL_DELAY 24
+
+uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
+uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
+
+#define SLAVE_DATA_CORRUPT (1<<0)
+volatile uint8_t status = 0;
+
+inline static
+void serial_delay(void) {
+  _delay_us(SERIAL_DELAY);
+}
+
+inline static
+void serial_output(void) {
+  SERIAL_PIN_DDR |= SERIAL_PIN_MASK;
+}
+
+// make the serial pin an input with pull-up resistor
+inline static
+void serial_input(void) {
+  SERIAL_PIN_DDR  &= ~SERIAL_PIN_MASK;
+  SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
+}
+
+inline static
+uint8_t serial_read_pin(void) {
+  return !!(SERIAL_PIN_INPUT & SERIAL_PIN_MASK);
+}
+
+inline static
+void serial_low(void) {
+  SERIAL_PIN_PORT &= ~SERIAL_PIN_MASK;
+}
+
+inline static
+void serial_high(void) {
+  SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
+}
+
+void serial_master_init(void) {
+  serial_output();
+  serial_high();
+}
+
+void serial_slave_init(void) {
+  serial_input();
+
+  // Enable INT0
+  EIMSK |= _BV(INT0);
+  // Trigger on falling edge of INT0
+  EICRA &= ~(_BV(ISC00) | _BV(ISC01));
+}
+
+// Used by the master to synchronize timing with the slave.
+static
+void sync_recv(void) {
+  serial_input();
+  // This shouldn't hang if the slave disconnects because the
+  // serial line will float to high if the slave does disconnect.
+  while (!serial_read_pin());
+  serial_delay();
+}
+
+// Used by the slave to send a synchronization signal to the master.
+static
+void sync_send(void) {
+  serial_output();
+
+  serial_low();
+  serial_delay();
+
+  serial_high();
+}
+
+// Reads a byte from the serial line
+static
+uint8_t serial_read_byte(void) {
+  uint8_t byte = 0;
+  serial_input();
+  for ( uint8_t i = 0; i < 8; ++i) {
+    byte = (byte << 1) | serial_read_pin();
+    serial_delay();
+    _delay_us(1);
+  }
+
+  return byte;
+}
+
+// Sends a byte with MSB ordering
+static
+void serial_write_byte(uint8_t data) {
+  uint8_t b = 8;
+  serial_output();
+  while( b-- ) {
+    if(data & (1 << b)) {
+      serial_high();
+    } else {
+      serial_low();
+    }
+    serial_delay();
+  }
+}
+
+// interrupt handle to be used by the slave device
+ISR(SERIAL_PIN_INTERRUPT) {
+  sync_send();
+
+  uint8_t checksum = 0;
+  for (int i = 0; i < SERIAL_SLAVE_BUFFER_LENGTH; ++i) {
+    serial_write_byte(serial_slave_buffer[i]);
+    sync_send();
+    checksum += serial_slave_buffer[i];
+  }
+  serial_write_byte(checksum);
+  sync_send();
+
+  // wait for the sync to finish sending
+  serial_delay();
+
+  // read the middle of pulses
+  _delay_us(SERIAL_DELAY/2);
+
+  uint8_t checksum_computed = 0;
+  for (int i = 0; i < SERIAL_MASTER_BUFFER_LENGTH; ++i) {
+    serial_master_buffer[i] = serial_read_byte();
+    sync_send();
+    checksum_computed += serial_master_buffer[i];
+  }
+  uint8_t checksum_received = serial_read_byte();
+  sync_send();
+
+  serial_input(); // end transaction
+
+  if ( checksum_computed != checksum_received ) {
+    status |= SLAVE_DATA_CORRUPT;
+  } else {
+    status &= ~SLAVE_DATA_CORRUPT;
+  }
+}
+
+inline
+bool serial_slave_DATA_CORRUPT(void) {
+  return status & SLAVE_DATA_CORRUPT;
+}
+
+// Copies the serial_slave_buffer to the master and sends the
+// serial_master_buffer to the slave.
+//
+// Returns:
+// 0 => no error
+// 1 => slave did not respond
+int serial_update_buffers(void) {
+  // this code is very time dependent, so we need to disable interrupts
+  cli();
+
+  // signal to the slave that we want to start a transaction
+  serial_output();
+  serial_low();
+  _delay_us(1);
+
+  // wait for the slaves response
+  serial_input();
+  serial_high();
+  _delay_us(SERIAL_DELAY);
+
+  // check if the slave is present
+  if (serial_read_pin()) {
+    // slave failed to pull the line low, assume not present
+    sei();
+    return 1;
+  }
+
+  // if the slave is present syncronize with it
+  sync_recv();
+
+  uint8_t checksum_computed = 0;
+  // receive data from the slave
+  for (int i = 0; i < SERIAL_SLAVE_BUFFER_LENGTH; ++i) {
+    serial_slave_buffer[i] = serial_read_byte();
+    sync_recv();
+    checksum_computed += serial_slave_buffer[i];
+  }
+  uint8_t checksum_received = serial_read_byte();
+  sync_recv();
+
+  if (checksum_computed != checksum_received) {
+    sei();
+    return 1;
+  }
+
+  uint8_t checksum = 0;
+  // send data to the slave
+  for (int i = 0; i < SERIAL_MASTER_BUFFER_LENGTH; ++i) {
+    serial_write_byte(serial_master_buffer[i]);
+    sync_recv();
+    checksum += serial_master_buffer[i];
+  }
+  serial_write_byte(checksum);
+  sync_recv();
+
+  // always, release the line when not in use
+  serial_output();
+  serial_high();
+
+  sei();
+  return 0;
+}
+
+#endif
diff --git a/keyboards/viterbi/serial.h b/keyboards/viterbi/serial.h
new file mode 100644
index 000000000..15fe4db7b
--- /dev/null
+++ b/keyboards/viterbi/serial.h
@@ -0,0 +1,26 @@
+#ifndef MY_SERIAL_H
+#define MY_SERIAL_H
+
+#include "config.h"
+#include <stdbool.h>
+
+/* TODO:  some defines for interrupt setup */
+#define SERIAL_PIN_DDR DDRD
+#define SERIAL_PIN_PORT PORTD
+#define SERIAL_PIN_INPUT PIND
+#define SERIAL_PIN_MASK _BV(PD0)
+#define SERIAL_PIN_INTERRUPT INT0_vect
+
+#define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
+#define SERIAL_MASTER_BUFFER_LENGTH 1
+
+// Buffers for master - slave communication
+extern volatile uint8_t serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH];
+extern volatile uint8_t serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH];
+
+void serial_master_init(void);
+void serial_slave_init(void);
+int serial_update_buffers(void);
+bool serial_slave_data_corrupt(void);
+
+#endif
diff --git a/keyboards/viterbi/split_rgb.c b/keyboards/viterbi/split_rgb.c
new file mode 100644
index 000000000..6d7cb44cf
--- /dev/null
+++ b/keyboards/viterbi/split_rgb.c
@@ -0,0 +1,41 @@
+#include <stdint.h>
+#include <stdbool.h>
+#include "split_util.h"
+#include "progmem.h"
+#include "print.h"
+#include "rgblight.h"
+
+#ifdef USE_I2C
+#  include "i2c.h"
+#else // USE_SERIAL
+#  include "serial.h"
+#endif
+
+
+rgblight_config_t rgblight_config;
+
+void rgblight_slave_update(void) {
+  //rgblight_effect_christmas();
+}
+
+
+void rgblight_set(void) {
+  if (rgblight_config.enable) {
+    #ifdef RGBW
+      ws2812_setleds_rgbw(led, RGBLED_NUM);
+    #else
+      ws2812_setleds(led, RGBLED_NUM);
+    #endif
+  } else {
+    for (uint8_t i = 0; i < RGBLED_NUM; i++) {
+      led[i].r = 0;
+      led[i].g = 0;
+      led[i].b = 0;
+    }
+    #ifdef RGBW
+      ws2812_setleds_rgbw(led, RGBLED_NUM);
+    #else
+      ws2812_setleds(led, RGBLED_NUM);
+    #endif
+  }
+}
diff --git a/keyboards/viterbi/split_rgb.h b/keyboards/viterbi/split_rgb.h
new file mode 100644
index 000000000..5f552890a
--- /dev/null
+++ b/keyboards/viterbi/split_rgb.h
@@ -0,0 +1,6 @@
+#ifndef SPLIT_RGB_H
+#define SPLIT_RGB_H
+
+void rgblight_slave_update(void);
+
+#endif
diff --git a/keyboards/viterbi/split_util.c b/keyboards/viterbi/split_util.c
new file mode 100644
index 000000000..346cbc908
--- /dev/null
+++ b/keyboards/viterbi/split_util.c
@@ -0,0 +1,86 @@
+#include <avr/io.h>
+#include <avr/wdt.h>
+#include <avr/power.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <avr/eeprom.h>
+#include "split_util.h"
+#include "matrix.h"
+#include "keyboard.h"
+#include "config.h"
+#include "timer.h"
+
+#ifdef USE_I2C
+#  include "i2c.h"
+#else
+#  include "serial.h"
+#endif
+
+volatile bool isLeftHand = true;
+
+static void setup_handedness(void) {
+  #ifdef EE_HANDS
+    isLeftHand = eeprom_read_byte(EECONFIG_HANDEDNESS);
+  #else
+    // I2C_MASTER_RIGHT is deprecated, use MASTER_RIGHT instead, since this works for both serial and i2c
+    #if defined(I2C_MASTER_RIGHT) || defined(MASTER_RIGHT)
+      isLeftHand = !has_usb();
+    #else
+      isLeftHand = has_usb();
+    #endif
+  #endif
+}
+
+static void keyboard_master_setup(void) {
+#ifdef USE_I2C
+    i2c_master_init();
+#ifdef SSD1306OLED
+    matrix_master_OLED_init ();
+#endif
+#else
+    serial_master_init();
+#endif
+}
+
+static void keyboard_slave_setup(void) {
+  timer_init();
+#ifdef USE_I2C
+    i2c_slave_init(SLAVE_I2C_ADDRESS);
+#else
+    serial_slave_init();
+#endif
+}
+
+bool has_usb(void) {
+   USBCON |= (1 << OTGPADE); //enables VBUS pad
+   _delay_us(5);
+   return (USBSTA & (1<<VBUS));  //checks state of VBUS
+}
+
+void split_keyboard_setup(void) {
+   setup_handedness();
+
+   if (has_usb()) {
+      keyboard_master_setup();
+   } else {
+      keyboard_slave_setup();
+   }
+   sei();
+}
+
+void keyboard_slave_loop(void) {
+   matrix_init();
+
+   while (1) {
+      matrix_slave_scan();
+   }
+}
+
+// this code runs before the usb and keyboard is initialized
+void matrix_setup(void) {
+    split_keyboard_setup();
+
+    if (!has_usb()) {
+        keyboard_slave_loop();
+    }
+}
diff --git a/keyboards/viterbi/split_util.h b/keyboards/viterbi/split_util.h
new file mode 100644
index 000000000..3ae76c209
--- /dev/null
+++ b/keyboards/viterbi/split_util.h
@@ -0,0 +1,24 @@
+#ifndef SPLIT_KEYBOARD_UTIL_H
+#define SPLIT_KEYBOARD_UTIL_H
+
+#include <stdbool.h>
+
+#ifdef EE_HANDS
+        #define EECONFIG_BOOTMAGIC_END      (uint8_t *)10
+        #define EECONFIG_HANDEDNESS         EECONFIG_BOOTMAGIC_END
+#endif
+
+#define SLAVE_I2C_ADDRESS           0x32
+
+extern volatile bool isLeftHand;
+
+// slave version of matix scan, defined in matrix.c
+void matrix_slave_scan(void);
+
+void split_keyboard_setup(void);
+bool has_usb(void);
+void keyboard_slave_loop(void);
+
+void matrix_master_OLED_init (void);
+
+#endif