Adds IS31FL3731 RGB Matrix Implementation (#2910)

* adds is31fl3731 rgb matrix implementation

* fix build script for force pushes

* allow bootloader size to be overwritten

* adds planck light implementation

* split led config into 2 arrays

* idk

* betterize register handling

* update planck implementation

* update planck

* refine rgb interface

* cleanup names, rgb matrix

* start documentation

* finish up docs

* add effects list

* clean-up merge

* add RGB_MATRIX_SKIP_FRAMES

* add support for at90usb1286 to bootloader options

4 files changed, 786 insertions, 0 deletions

diff --git a/drivers/avr/TWIlib.c b/drivers/avr/TWIlib.c
new file mode 100644
index 000000000..b39e3054a
--- /dev/null
+++ b/drivers/avr/TWIlib.c
@@ -0,0 +1,232 @@
+/*
+ * TWIlib.c
+ *
+ *  Created: 6/01/2014 10:41:33 PM
+ *  Author: Chris Herring
+ *  http://www.chrisherring.net/all/tutorial-interrupt-driven-twi-interface-for-avr-part1/
+ */ 
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include "TWIlib.h"
+#include "util/delay.h"
+
+void TWIInit()
+{
+        TWIInfo.mode = Ready;
+        TWIInfo.errorCode = 0xFF;
+        TWIInfo.repStart = 0;
+        // Set pre-scalers (no pre-scaling)
+        TWSR = 0;
+        // Set bit rate
+        TWBR = ((F_CPU / TWI_FREQ) - 16) / 2;
+        // Enable TWI and interrupt
+        TWCR = (1 << TWIE) | (1 << TWEN);
+}
+
+uint8_t isTWIReady()
+{
+        if ( (TWIInfo.mode == Ready) | (TWIInfo.mode == RepeatedStartSent) )
+        {
+                return 1;
+        }
+        else
+        {
+                return 0;
+        }
+}
+
+uint8_t TWITransmitData(void *const TXdata, uint8_t dataLen, uint8_t repStart)
+{
+        if (dataLen <= TXMAXBUFLEN)
+        {
+                // Wait until ready
+                while (!isTWIReady()) {_delay_us(1);}
+                // Set repeated start mode
+                TWIInfo.repStart = repStart;
+                // Copy data into the transmit buffer
+                uint8_t *data = (uint8_t *)TXdata;
+                for (int i = 0; i < dataLen; i++)
+                {
+                        TWITransmitBuffer[i] = data[i];
+                }
+                // Copy transmit info to global variables
+                TXBuffLen = dataLen;
+                TXBuffIndex = 0;
+                
+                // If a repeated start has been sent, then devices are already listening for an address
+                // and another start does not need to be sent. 
+                if (TWIInfo.mode == RepeatedStartSent)
+                {
+                        TWIInfo.mode = Initializing;
+                        TWDR = TWITransmitBuffer[TXBuffIndex++]; // Load data to transmit buffer
+                        TWISendTransmit(); // Send the data
+                }
+                else // Otherwise, just send the normal start signal to begin transmission.
+                {
+                        TWIInfo.mode = Initializing;
+                        TWISendStart();
+                }
+                
+        }
+        else
+        {
+                return 1; // return an error if data length is longer than buffer
+        }
+        return 0;
+}
+
+uint8_t TWIReadData(uint8_t TWIaddr, uint8_t bytesToRead, uint8_t repStart)
+{
+        // Check if number of bytes to read can fit in the RXbuffer
+        if (bytesToRead < RXMAXBUFLEN)
+        {
+                // Reset buffer index and set RXBuffLen to the number of bytes to read
+                RXBuffIndex = 0;
+                RXBuffLen = bytesToRead;
+                // Create the one value array for the address to be transmitted
+                uint8_t TXdata[1];
+                // Shift the address and AND a 1 into the read write bit (set to write mode)
+                TXdata[0] = (TWIaddr << 1) | 0x01;
+                // Use the TWITransmitData function to initialize the transfer and address the slave
+                TWITransmitData(TXdata, 1, repStart);
+        }
+        else
+        {
+                return 0;
+        }
+        return 1;
+}
+
+ISR (TWI_vect)
+{
+        switch (TWI_STATUS)
+        {
+                // ----\/ ---- MASTER TRANSMITTER OR WRITING ADDRESS ----\/ ----  //
+                case TWI_MT_SLAW_ACK: // SLA+W transmitted and ACK received
+                // Set mode to Master Transmitter
+                TWIInfo.mode = MasterTransmitter;
+                case TWI_START_SENT: // Start condition has been transmitted
+                case TWI_MT_DATA_ACK: // Data byte has been transmitted, ACK received
+                        if (TXBuffIndex < TXBuffLen) // If there is more data to send
+                        {
+                                TWDR = TWITransmitBuffer[TXBuffIndex++]; // Load data to transmit buffer
+                                TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
+                                TWISendTransmit(); // Send the data
+                        }
+                        // This transmission is complete however do not release bus yet
+                        else if (TWIInfo.repStart)
+                        {
+                                TWIInfo.errorCode = 0xFF;
+                                TWISendStart();
+                        }
+                        // All transmissions are complete, exit
+                        else
+                        {
+                                TWIInfo.mode = Ready;
+                                TWIInfo.errorCode = 0xFF;
+                                TWISendStop();
+                        }
+                        break;
+                
+                // ----\/ ---- MASTER RECEIVER ----\/ ----  //
+                
+                case TWI_MR_SLAR_ACK: // SLA+R has been transmitted, ACK has been received
+                        // Switch to Master Receiver mode
+                        TWIInfo.mode = MasterReceiver;
+                        // If there is more than one byte to be read, receive data byte and return an ACK
+                        if (RXBuffIndex < RXBuffLen-1)
+                        {
+                                TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
+                                TWISendACK();
+                        }
+                        // Otherwise when a data byte (the only data byte) is received, return NACK
+                        else
+                        {
+                                TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
+                                TWISendNACK();
+                        }
+                        break;
+                
+                case TWI_MR_DATA_ACK: // Data has been received, ACK has been transmitted.
+                
+                        /// -- HANDLE DATA BYTE --- ///
+                        TWIReceiveBuffer[RXBuffIndex++] = TWDR;
+                        // If there is more than one byte to be read, receive data byte and return an ACK
+                        if (RXBuffIndex < RXBuffLen-1)
+                        {
+                                TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
+                                TWISendACK();
+                        }
+                        // Otherwise when a data byte (the only data byte) is received, return NACK
+                        else
+                        {
+                                TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
+                                TWISendNACK();
+                        }
+                        break;
+                
+                case TWI_MR_DATA_NACK: // Data byte has been received, NACK has been transmitted. End of transmission.
+                
+                        /// -- HANDLE DATA BYTE --- ///
+                        TWIReceiveBuffer[RXBuffIndex++] = TWDR; 
+                        // This transmission is complete however do not release bus yet
+                        if (TWIInfo.repStart)
+                        {
+                                TWIInfo.errorCode = 0xFF;
+                                TWISendStart();
+                        }
+                        // All transmissions are complete, exit
+                        else
+                        {
+                                TWIInfo.mode = Ready;
+                                TWIInfo.errorCode = 0xFF;
+                                TWISendStop();
+                        }
+                        break;
+                
+                // ----\/ ---- MT and MR common ----\/ ---- //
+                
+                case TWI_MR_SLAR_NACK: // SLA+R transmitted, NACK received
+                case TWI_MT_SLAW_NACK: // SLA+W transmitted, NACK received
+                case TWI_MT_DATA_NACK: // Data byte has been transmitted, NACK received
+                case TWI_LOST_ARBIT: // Arbitration has been lost
+                        // Return error and send stop and set mode to ready
+                        if (TWIInfo.repStart)
+                        {                               
+                                TWIInfo.errorCode = TWI_STATUS;
+                                TWISendStart();
+                        }
+                        // All transmissions are complete, exit
+                        else
+                        {
+                                TWIInfo.mode = Ready;
+                                TWIInfo.errorCode = TWI_STATUS;
+                                TWISendStop();
+                        }
+                        break;
+                case TWI_REP_START_SENT: // Repeated start has been transmitted
+                        // Set the mode but DO NOT clear TWINT as the next data is not yet ready
+                        TWIInfo.mode = RepeatedStartSent;
+                        break;
+                
+                // ----\/ ---- SLAVE RECEIVER ----\/ ----  //
+                
+                // TODO  IMPLEMENT SLAVE RECEIVER FUNCTIONALITY
+                
+                // ----\/ ---- SLAVE TRANSMITTER ----\/ ----  //
+                
+                // TODO  IMPLEMENT SLAVE TRANSMITTER FUNCTIONALITY
+                
+                // ----\/ ---- MISCELLANEOUS STATES ----\/ ----  //
+                case TWI_NO_RELEVANT_INFO: // It is not really possible to get into this ISR on this condition
+                                                                   // Rather, it is there to be manually set between operations
+                        break;
+                case TWI_ILLEGAL_START_STOP: // Illegal START/STOP, abort and return error
+                        TWIInfo.errorCode = TWI_ILLEGAL_START_STOP;
+                        TWIInfo.mode = Ready;
+                        TWISendStop();
+                        break;
+        }
+        
+}
diff --git a/drivers/avr/TWIlib.h b/drivers/avr/TWIlib.h
new file mode 100644
index 000000000..23fd1f09a
--- /dev/null
+++ b/drivers/avr/TWIlib.h
@@ -0,0 +1,82 @@
+/*
+ * TWIlib.h
+ *
+ * Created: 6/01/2014 10:38:42 PM
+ *  Author: Chris Herring
+ *  http://www.chrisherring.net/all/tutorial-interrupt-driven-twi-interface-for-avr-part1/
+ */ 
+
+
+#ifndef TWILIB_H_
+#define TWILIB_H_
+// TWI bit rate (was 100000)
+#define TWI_FREQ 400000
+// Get TWI status
+#define TWI_STATUS      (TWSR & 0xF8) 
+// Transmit buffer length
+#define TXMAXBUFLEN 20
+// Receive buffer length
+#define RXMAXBUFLEN 20
+// Global transmit buffer
+uint8_t TWITransmitBuffer[TXMAXBUFLEN];
+// Global receive buffer
+volatile uint8_t TWIReceiveBuffer[RXMAXBUFLEN];
+// Buffer indexes
+volatile int TXBuffIndex; // Index of the transmit buffer. Is volatile, can change at any time.
+int RXBuffIndex; // Current index in the receive buffer
+// Buffer lengths
+int TXBuffLen; // The total length of the transmit buffer
+int RXBuffLen; // The total number of bytes to read (should be less than RXMAXBUFFLEN)
+
+typedef enum {
+        Ready,
+        Initializing,
+        RepeatedStartSent,
+        MasterTransmitter,
+        MasterReceiver,
+        SlaceTransmitter,
+        SlaveReciever
+        } TWIMode;
+
+ typedef struct TWIInfoStruct{
+        TWIMode mode;
+        uint8_t errorCode;
+        uint8_t repStart;       
+        }TWIInfoStruct;
+TWIInfoStruct TWIInfo;
+
+
+// TWI Status Codes
+#define TWI_START_SENT                  0x08 // Start sent
+#define TWI_REP_START_SENT              0x10 // Repeated Start sent
+// Master Transmitter Mode
+#define TWI_MT_SLAW_ACK                 0x18 // SLA+W sent and ACK received
+#define TWI_MT_SLAW_NACK                0x20 // SLA+W sent and NACK received
+#define TWI_MT_DATA_ACK                 0x28 // DATA sent and ACK received
+#define TWI_MT_DATA_NACK                0x30 // DATA sent and NACK received
+// Master Receiver Mode
+#define TWI_MR_SLAR_ACK                 0x40 // SLA+R sent, ACK received
+#define TWI_MR_SLAR_NACK                0x48 // SLA+R sent, NACK received
+#define TWI_MR_DATA_ACK                 0x50 // Data received, ACK returned
+#define TWI_MR_DATA_NACK                0x58 // Data received, NACK returned
+
+// Miscellaneous States
+#define TWI_LOST_ARBIT                  0x38 // Arbitration has been lost
+#define TWI_NO_RELEVANT_INFO    0xF8 // No relevant information available
+#define TWI_ILLEGAL_START_STOP  0x00 // Illegal START or STOP condition has been detected
+#define TWI_SUCCESS                             0xFF // Successful transfer, this state is impossible from TWSR as bit2 is 0 and read only
+
+
+#define TWISendStart()          (TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN)|(1<<TWIE)) // Send the START signal, enable interrupts and TWI, clear TWINT flag to resume transfer.
+#define TWISendStop()           (TWCR = (1<<TWINT)|(1<<TWSTO)|(1<<TWEN)|(1<<TWIE)) // Send the STOP signal, enable interrupts and TWI, clear TWINT flag.
+#define TWISendTransmit()       (TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWIE)) // Used to resume a transfer, clear TWINT and ensure that TWI and interrupts are enabled.
+#define TWISendACK()            (TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWIE)|(1<<TWEA)) // FOR MR mode. Resume a transfer, ensure that TWI and interrupts are enabled and respond with an ACK if the device is addressed as a slave or after it receives a byte.
+#define TWISendNACK()           (TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWIE)) // FOR MR mode. Resume a transfer, ensure that TWI and interrupts are enabled but DO NOT respond with an ACK if the device is addressed as a slave or after it receives a byte.
+
+// Function declarations
+uint8_t TWITransmitData(void *const TXdata, uint8_t dataLen, uint8_t repStart);
+void TWIInit(void);
+uint8_t TWIReadData(uint8_t TWIaddr, uint8_t bytesToRead, uint8_t repStart);
+uint8_t isTWIReady(void);
+
+#endif // TWICOMMS_H_ 
\ No newline at end of file
diff --git a/drivers/avr/is31fl3731.c b/drivers/avr/is31fl3731.c
new file mode 100644
index 000000000..e5941cf41
--- /dev/null
+++ b/drivers/avr/is31fl3731.c
@@ -0,0 +1,258 @@
+/* Copyright 2017 Jason Williams
+ * Copyright 2018 Jack Humbert
+ *
+ * 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/>.
+ */
+
+#include "is31fl3731.h"
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include <string.h>
+#include "TWIlib.h"
+#include "progmem.h"
+
+// This is a 7-bit address, that gets left-shifted and bit 0
+// set to 0 for write, 1 for read (as per I2C protocol)
+// The address will vary depending on your wiring:
+// 0b1110100 AD <-> GND
+// 0b1110111 AD <-> VCC
+// 0b1110101 AD <-> SCL
+// 0b1110110 AD <-> SDA
+#define ISSI_ADDR_DEFAULT 0x74
+
+#define ISSI_REG_CONFIG  0x00
+#define ISSI_REG_CONFIG_PICTUREMODE 0x00
+#define ISSI_REG_CONFIG_AUTOPLAYMODE 0x08
+#define ISSI_REG_CONFIG_AUDIOPLAYMODE 0x18
+
+#define ISSI_CONF_PICTUREMODE 0x00
+#define ISSI_CONF_AUTOFRAMEMODE 0x04
+#define ISSI_CONF_AUDIOMODE 0x08
+
+#define ISSI_REG_PICTUREFRAME  0x01
+
+#define ISSI_REG_SHUTDOWN 0x0A
+#define ISSI_REG_AUDIOSYNC 0x06
+
+#define ISSI_COMMANDREGISTER 0xFD
+#define ISSI_BANK_FUNCTIONREG 0x0B    // helpfully called 'page nine'
+
+// Transfer buffer for TWITransmitData()
+uint8_t g_twi_transfer_buffer[TXMAXBUFLEN];
+
+// These buffers match the IS31FL3731 PWM registers 0x24-0xB3.
+// Storing them like this is optimal for I2C transfers to the registers.
+// We could optimize this and take out the unused registers from these
+// buffers and the transfers in IS31FL3731_write_pwm_buffer() but it's
+// probably not worth the extra complexity.
+uint8_t g_pwm_buffer[DRIVER_COUNT][144];
+bool g_pwm_buffer_update_required = false;
+
+uint8_t g_led_control_registers[DRIVER_COUNT][18] = { { 0 }, { 0 } };
+bool g_led_control_registers_update_required = false;
+
+// This is the bit pattern in the LED control registers
+// (for matrix A, add one to register for matrix B)
+//
+//  reg -  b7  b6  b5  b4  b3  b2  b1  b0
+// 0x00 - R08,R07,R06,R05,R04,R03,R02,R01
+// 0x02 - G08,G07,G06,G05,G04,G03,G02,R00
+// 0x04 - B08,B07,B06,B05,B04,B03,G01,G00
+// 0x06 -  - , - , - , - , - ,B02,B01,B00
+// 0x08 -  - , - , - , - , - , - , - , -
+// 0x0A - B17,B16,B15, - , - , - , - , -
+// 0x0C - G17,G16,B14,B13,B12,B11,B10,B09
+// 0x0E - R17,G15,G14,G13,G12,G11,G10,G09
+// 0x10 - R16,R15,R14,R13,R12,R11,R10,R09
+
+
+void IS31FL3731_write_register( uint8_t addr, uint8_t reg, uint8_t data )
+{
+        g_twi_transfer_buffer[0] = (addr << 1) | 0x00;
+        g_twi_transfer_buffer[1] = reg;
+        g_twi_transfer_buffer[2] = data;
+
+        // Set the error code to have no relevant information
+        TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
+        // Continuously attempt to transmit data until a successful transmission occurs
+        //while ( TWIInfo.errorCode != 0xFF )
+        //{
+                TWITransmitData( g_twi_transfer_buffer, 3, 0 );
+        //}
+}
+
+void IS31FL3731_write_pwm_buffer( uint8_t addr, uint8_t *pwm_buffer )
+{
+        // assumes bank is already selected
+
+        // transmit PWM registers in 9 transfers of 16 bytes
+        // g_twi_transfer_buffer[] is 20 bytes
+
+        // set the I2C address
+        g_twi_transfer_buffer[0] = (addr << 1) | 0x00;
+
+        // iterate over the pwm_buffer contents at 16 byte intervals
+        for ( int i = 0; i < 144; i += 16 )
+        {
+                // set the first register, e.g. 0x24, 0x34, 0x44, etc.
+                g_twi_transfer_buffer[1] = 0x24 + i;
+                // copy the data from i to i+15
+                // device will auto-increment register for data after the first byte
+                // thus this sets registers 0x24-0x33, 0x34-0x43, etc. in one transfer
+                for ( int j = 0; j < 16; j++ )
+                {
+                        g_twi_transfer_buffer[2 + j] = pwm_buffer[i + j];
+                }
+
+                // Set the error code to have no relevant information
+                TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
+                // Continuously attempt to transmit data until a successful transmission occurs
+                while ( TWIInfo.errorCode != 0xFF )
+                {
+                        TWITransmitData( g_twi_transfer_buffer, 16 + 2, 0 );
+                }
+        }
+}
+
+void IS31FL3731_init( uint8_t addr )
+{
+        // In order to avoid the LEDs being driven with garbage data
+        // in the LED driver's PWM registers, first enable software shutdown,
+        // then set up the mode and other settings, clear the PWM registers,
+        // then disable software shutdown.
+
+        // select "function register" bank
+        IS31FL3731_write_register( addr, ISSI_COMMANDREGISTER, ISSI_BANK_FUNCTIONREG );
+
+        // enable software shutdown
+        IS31FL3731_write_register( addr, ISSI_REG_SHUTDOWN, 0x00 );
+        // this delay was copied from other drivers, might not be needed
+        _delay_ms( 10 );
+
+        // picture mode
+        IS31FL3731_write_register( addr, ISSI_REG_CONFIG, ISSI_REG_CONFIG_PICTUREMODE );
+        // display frame 0
+        IS31FL3731_write_register( addr, ISSI_REG_PICTUREFRAME, 0x00 );
+        // audio sync off
+        IS31FL3731_write_register( addr, ISSI_REG_AUDIOSYNC, 0x00 );
+
+        // select bank 0
+        IS31FL3731_write_register( addr, ISSI_COMMANDREGISTER, 0 );
+
+        // turn off all LEDs in the LED control register
+        for ( int i = 0x00; i <= 0x11; i++ )
+        {
+                IS31FL3731_write_register( addr, i, 0x00 );
+        }
+
+        // turn off all LEDs in the blink control register (not really needed)
+        for ( int i = 0x12; i <= 0x23; i++ )
+        {
+                IS31FL3731_write_register( addr, i, 0x00 );
+        }
+
+        // set PWM on all LEDs to 0
+        for ( int i = 0x24; i <= 0xB3; i++ )
+        {
+                IS31FL3731_write_register( addr, i, 0x00 );
+        }
+
+        // select "function register" bank
+        IS31FL3731_write_register( addr, ISSI_COMMANDREGISTER, ISSI_BANK_FUNCTIONREG );
+
+        // disable software shutdown
+        IS31FL3731_write_register( addr, ISSI_REG_SHUTDOWN, 0x01 );
+
+        // select bank 0 and leave it selected.
+        // most usage after initialization is just writing PWM buffers in bank 0
+        // as there's not much point in double-buffering
+        IS31FL3731_write_register( addr, ISSI_COMMANDREGISTER, 0 );
+}
+
+void IS31FL3731_set_color( int index, uint8_t red, uint8_t green, uint8_t blue )
+{
+        if ( index >= 0 && index < DRIVER_LED_TOTAL ) {
+                is31_led led = g_is31_leds[index];
+
+                // Subtract 0x24 to get the second index of g_pwm_buffer
+                g_pwm_buffer[led.driver][led.r - 0x24] = red;
+                g_pwm_buffer[led.driver][led.g - 0x24] = green;
+                g_pwm_buffer[led.driver][led.b - 0x24] = blue;
+                g_pwm_buffer_update_required = true;
+        }
+}
+
+void IS31FL3731_set_color_all( uint8_t red, uint8_t green, uint8_t blue )
+{
+        for ( int i = 0; i < DRIVER_LED_TOTAL; i++ )
+        {
+                IS31FL3731_set_color( i, red, green, blue );
+        }
+}
+
+void IS31FL3731_set_led_control_register( uint8_t index, bool red, bool green, bool blue )
+{
+        is31_led led = g_is31_leds[index];
+
+  uint8_t control_register_r = (led.r - 0x24) / 8;
+  uint8_t control_register_g = (led.g - 0x24) / 8;
+  uint8_t control_register_b = (led.b - 0x24) / 8;
+  uint8_t bit_r = (led.r - 0x24) % 8;
+  uint8_t bit_g = (led.g - 0x24) % 8;
+  uint8_t bit_b = (led.b - 0x24) % 8;
+
+        if ( red ) {
+                g_led_control_registers[led.driver][control_register_r] |= (1 << bit_r);
+        } else {
+                g_led_control_registers[led.driver][control_register_r] &= ~(1 << bit_r);
+        }
+        if ( green ) {
+                g_led_control_registers[led.driver][control_register_g] |= (1 << bit_g);
+        } else {
+                g_led_control_registers[led.driver][control_register_g] &= ~(1 << bit_g);
+        }
+        if ( blue ) {
+                g_led_control_registers[led.driver][control_register_b] |= (1 << bit_b);
+        } else {
+                g_led_control_registers[led.driver][control_register_b] &= ~(1 << bit_b);
+        }
+
+        g_led_control_registers_update_required = true;
+
+
+}
+
+void IS31FL3731_update_pwm_buffers( uint8_t addr1, uint8_t addr2 )
+{
+        if ( g_pwm_buffer_update_required )
+        {
+                IS31FL3731_write_pwm_buffer( addr1, g_pwm_buffer[0] );
+                IS31FL3731_write_pwm_buffer( addr2, g_pwm_buffer[1] );
+        }
+        g_pwm_buffer_update_required = false;
+}
+
+void IS31FL3731_update_led_control_registers( uint8_t addr1, uint8_t addr2 )
+{
+        if ( g_led_control_registers_update_required )
+        {
+                for ( int i=0; i<18; i++ )
+                {
+                        IS31FL3731_write_register(addr1, i, g_led_control_registers[0][i] );
+                        IS31FL3731_write_register(addr2, i, g_led_control_registers[1][i] );
+                }
+        }
+}
+
diff --git a/drivers/avr/is31fl3731.h b/drivers/avr/is31fl3731.h
new file mode 100644
index 000000000..3d30fc67b
--- /dev/null
+++ b/drivers/avr/is31fl3731.h
@@ -0,0 +1,214 @@
+/* Copyright 2017 Jason Williams
+ * Copyright 2018 Jack Humbert
+ *
+ * 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 IS31FL3731_DRIVER_H
+#define IS31FL3731_DRIVER_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+typedef struct is31_led {
+        uint8_t driver:2;
+  uint8_t r;
+  uint8_t g;
+  uint8_t b;
+} __attribute__((packed)) is31_led;
+
+extern const is31_led g_is31_leds[DRIVER_LED_TOTAL];
+
+void IS31FL3731_init( uint8_t addr );
+void IS31FL3731_write_register( uint8_t addr, uint8_t reg, uint8_t data );
+void IS31FL3731_write_pwm_buffer( uint8_t addr, uint8_t *pwm_buffer );
+
+void IS31FL3731_set_color( int index, uint8_t red, uint8_t green, uint8_t blue );
+void IS31FL3731_set_color_all( uint8_t red, uint8_t green, uint8_t blue );
+
+void IS31FL3731_set_led_control_register( uint8_t index, bool red, bool green, bool blue );
+
+// This should not be called from an interrupt
+// (eg. from a timer interrupt).
+// Call this while idle (in between matrix scans).
+// If the buffer is dirty, it will update the driver with the buffer.
+void IS31FL3731_update_pwm_buffers( uint8_t addr1, uint8_t addr2 );
+void IS31FL3731_update_led_control_registers( uint8_t addr1, uint8_t addr2 );
+
+#define C1_1  0x24
+#define C1_2  0x25
+#define C1_3  0x26
+#define C1_4  0x27
+#define C1_5  0x28
+#define C1_6  0x29
+#define C1_7  0x2A
+#define C1_8  0x2B
+
+#define C1_9  0x2C
+#define C1_10 0x2D
+#define C1_11 0x2E
+#define C1_12 0x2F
+#define C1_13 0x30
+#define C1_14 0x31
+#define C1_15 0x32
+#define C1_16 0x33
+
+#define C2_1  0x34
+#define C2_2  0x35
+#define C2_3  0x36
+#define C2_4  0x37
+#define C2_5  0x38
+#define C2_6  0x39
+#define C2_7  0x3A
+#define C2_8  0x3B
+
+#define C2_9  0x3C
+#define C2_10 0x3D
+#define C2_11 0x3E
+#define C2_12 0x3F
+#define C2_13 0x40
+#define C2_14 0x41
+#define C2_15 0x42
+#define C2_16 0x43
+
+#define C3_1  0x44
+#define C3_2  0x45
+#define C3_3  0x46
+#define C3_4  0x47
+#define C3_5  0x48
+#define C3_6  0x49
+#define C3_7  0x4A
+#define C3_8  0x4B
+
+#define C3_9  0x4C
+#define C3_10 0x4D
+#define C3_11 0x4E
+#define C3_12 0x4F
+#define C3_13 0x50
+#define C3_14 0x51
+#define C3_15 0x52
+#define C3_16 0x53
+
+#define C4_1  0x54
+#define C4_2  0x55
+#define C4_3  0x56
+#define C4_4  0x57
+#define C4_5  0x58
+#define C4_6  0x59
+#define C4_7  0x5A
+#define C4_8  0x5B
+
+#define C4_9  0x5C
+#define C4_10 0x5D
+#define C4_11 0x5E
+#define C4_12 0x5F
+#define C4_13 0x60
+#define C4_14 0x61
+#define C4_15 0x62
+#define C4_16 0x63
+
+#define C5_1  0x64
+#define C5_2  0x65
+#define C5_3  0x66
+#define C5_4  0x67
+#define C5_5  0x68
+#define C5_6  0x69
+#define C5_7  0x6A
+#define C5_8  0x6B
+
+#define C5_9  0x6C
+#define C5_10 0x6D
+#define C5_11 0x6E
+#define C5_12 0x6F
+#define C5_13 0x70
+#define C5_14 0x71
+#define C5_15 0x72
+#define C5_16 0x73
+
+#define C6_1  0x74
+#define C6_2  0x75
+#define C6_3  0x76
+#define C6_4  0x77
+#define C6_5  0x78
+#define C6_6  0x79
+#define C6_7  0x7A
+#define C6_8  0x7B
+
+#define C6_9  0x7C
+#define C6_10 0x7D
+#define C6_11 0x7E
+#define C6_12 0x7F
+#define C6_13 0x80
+#define C6_14 0x81
+#define C6_15 0x82
+#define C6_16 0x83
+
+#define C7_1  0x84
+#define C7_2  0x85
+#define C7_3  0x86
+#define C7_4  0x87
+#define C7_5  0x88
+#define C7_6  0x89
+#define C7_7  0x8A
+#define C7_8  0x8B
+
+#define C7_9  0x8C
+#define C7_10 0x8D
+#define C7_11 0x8E
+#define C7_12 0x8F
+#define C7_13 0x90
+#define C7_14 0x91
+#define C7_15 0x92
+#define C7_16 0x93
+
+#define C8_1  0x94
+#define C8_2  0x95
+#define C8_3  0x96
+#define C8_4  0x97
+#define C8_5  0x98
+#define C8_6  0x99
+#define C8_7  0x9A
+#define C8_8  0x9B
+
+#define C8_9  0x9C
+#define C8_10 0x9D
+#define C8_11 0x9E
+#define C8_12 0x9F
+#define C8_13 0xA0
+#define C8_14 0xA1
+#define C8_15 0xA2
+#define C8_16 0xA3
+
+#define C9_1  0xA4
+#define C9_2  0xA5
+#define C9_3  0xA6
+#define C9_4  0xA7
+#define C9_5  0xA8
+#define C9_6  0xA9
+#define C9_7  0xAA
+#define C9_8  0xAB
+
+#define C9_9  0xAC
+#define C9_10 0xAD
+#define C9_11 0xAE
+#define C9_12 0xAF
+#define C9_13 0xB0
+#define C9_14 0xB1
+#define C9_15 0xB2
+#define C9_16 0xB3
+
+
+
+#endif // IS31FL3731_DRIVER_H