Lets split eh (#3120)

* Line ending stuff again

* Added Let's Split Eh? Files and updated #USE_IC2 checks to also include th EH revision (can only be used in I2C)

* Added personal keymap, updated some of the EH files

* Created new keyboard file for testing "lets_split_eh" will merge into lets_split once fully functional

* Added split code from lets_split, removed pro micro imports and LED code

THIS IS WORKING CODE, WITHOUT RGB AND BACKLIGHT

* Took back original Lets Slit files for the lets_split keyboard, working in the lets_split_eh folder for now

* Updated eh.c

* More rework of the I2C code, added global flags for split boards.

* Introduced RGB over I2C, having weird edge case issues at the moment though

* Fixed weird I2C edgecase with RGB, although still would like to track down route cause..

* Changed RGB keycodes (static ones) to activate on key-up instead of key-down to elimate weird ghosting issue over I2C

* Lots of changes, mainly externalized the Split keyboard code and added logic for only including when needed.

- Added makefile option "SPLIT_KEYBOARD" that when = yes will include the split keyboard files and custom matrix
- Split keyboard files placed into quantum/split_common/
- Added define option for config files "SPLIT_HAND_PIN" FOr using high/low pin to determine handedness, low = right hand, high = left hand
- Cleaned up split logic for RGB and Backlight so it is only exectuted / included when needed

* Updated documentation for the new makefile options and #defines specific to split keyboards

* Added a bit more info to docs, so people aren't confused

* Modifed Let's Split to use externalized code, also added left and right hand eeprom files to the split_common folder

* Removed some debugging from eh.c

* Small changes to keyboard configs. Also added a default keymap (just a copy of my that_canadian keymap).

* Added a README file to the Let's Split Eh?

* Changed it so RGB static updates are done on key-up ONLY for split boards rather than all boards. Also fixed leftover un-used variable in rgblight.c

* Updated default keymap and my keymap for Let's Split Eh? Updated the comments so it reflects RGB control, and removed audio functions.

* Fixed lets_split_eh not having a default version

* Removed "eh" references from lets_split folder for now

* Took lets_split folder from master to fix travis build errors, weird my local was overriding.

* Changed LAYOUT_ortho_4x12_kc -> LAYOUT_kc_ortho_4x12 to match bakingpy and others

* Removed rules.mk from my lets_split keymap, not needed

* Updated the config_options doc to better explain the usage of "#define SPLIT_HAND_PIN"

1 files changed, 228 insertions, 0 deletions

diff --git a/quantum/split_common/serial.c b/quantum/split_common/serial.c
new file mode 100644
index 000000000..74bcbb6bf
--- /dev/null
+++ b/quantum/split_common/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"
+
+#ifndef USE_I2C
+
+// 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