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author | That-Canadian <[email protected]> | 2018-07-16 19:25:02 -0700 |
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committer | Jack Humbert <[email protected]> | 2018-07-16 22:25:02 -0400 |
commit | 0fab3bbde33f82301a8c5e177c3c0ceb7ad2219c (patch) | |
tree | 15a411d5ed6ad203982337448cfde11ed26ce7b7 /quantum/split_common/serial.c | |
parent | b2877470ced1deb9651ecb39f6a82f5ef380b399 (diff) | |
download | qmk_firmware-0fab3bbde33f82301a8c5e177c3c0ceb7ad2219c.tar.gz qmk_firmware-0fab3bbde33f82301a8c5e177c3c0ceb7ad2219c.zip |
Lets split eh (#3120)0.6.69
* 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"
Diffstat (limited to 'quantum/split_common/serial.c')
-rw-r--r-- | quantum/split_common/serial.c | 228 |
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 0000000000..74bcbb6bf6 --- /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 |