Rename i2c_slave functions so it can coexist with i2c_master (#4875)

Also merges tx/rx buffers, as only one is necessary.
This commit is contained in:
James Churchill 2019-01-23 02:57:13 +10:00 committed by Drashna Jaelre
parent 127ec5f1e3
commit 8cf7265f8f
5 changed files with 36 additions and 38 deletions

View File

@ -9,22 +9,25 @@
#include "i2c_slave.h" #include "i2c_slave.h"
void i2c_init(uint8_t address){ volatile uint8_t i2c_slave_reg[I2C_SLAVE_REG_COUNT];
static volatile uint8_t buffer_address;
static volatile bool slave_has_register_set = false;
void i2c_slave_init(uint8_t address){
// load address into TWI address register // load address into TWI address register
TWAR = (address << 1); TWAR = (address << 1);
// set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt // set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt
TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN); TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN);
} }
void i2c_stop(void){ void i2c_slave_stop(void){
// clear acknowledge and enable bits // clear acknowledge and enable bits
TWCR &= ~((1 << TWEA) | (1 << TWEN)); TWCR &= ~((1 << TWEA) | (1 << TWEN));
} }
ISR(TWI_vect){ ISR(TWI_vect){
uint8_t ack = 1; uint8_t ack = 1;
// temporary stores the received data
//uint8_t data;
switch(TW_STATUS){ switch(TW_STATUS){
case TW_SR_SLA_ACK: case TW_SR_SLA_ACK:
@ -38,13 +41,13 @@ ISR(TWI_vect){
if(!slave_has_register_set){ if(!slave_has_register_set){
buffer_address = TWDR; buffer_address = TWDR;
if (buffer_address >= RX_BUFFER_SIZE){ // address out of bounds dont ack if (buffer_address >= I2C_SLAVE_REG_COUNT) { // address out of bounds dont ack
ack = 0; ack = 0;
buffer_address = 0; buffer_address = 0;
} }
slave_has_register_set = true; // address has been receaved now fill in buffer slave_has_register_set = true; // address has been receaved now fill in buffer
} else { } else {
rxbuffer[buffer_address] = TWDR; i2c_slave_reg[buffer_address] = TWDR;
buffer_address++; buffer_address++;
} }
break; break;
@ -52,7 +55,7 @@ ISR(TWI_vect){
case TW_ST_SLA_ACK: case TW_ST_SLA_ACK:
case TW_ST_DATA_ACK: case TW_ST_DATA_ACK:
// This device is a slave transmitter and master has requested data // This device is a slave transmitter and master has requested data
TWDR = txbuffer[buffer_address]; TWDR = i2c_slave_reg[buffer_address];
buffer_address++; buffer_address++;
break; break;
@ -63,6 +66,6 @@ ISR(TWI_vect){
break; break;
} }
// Reset i2c state mahcine to be ready for next interrupt // Reset i2c state machine to be ready for next interrupt
TWCR |= (1 << TWIE) | (1 << TWINT) | (ack << TWEA) | (1 << TWEN); TWCR |= (1 << TWIE) | (1 << TWINT) | (ack << TWEA) | (1 << TWEN);
} }

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@ -8,16 +8,11 @@
#ifndef I2C_SLAVE_H #ifndef I2C_SLAVE_H
#define I2C_SLAVE_H #define I2C_SLAVE_H
#define TX_BUFFER_SIZE 30 #define I2C_SLAVE_REG_COUNT 30
#define RX_BUFFER_SIZE 30
volatile uint8_t buffer_address; extern volatile uint8_t i2c_slave_reg[I2C_SLAVE_REG_COUNT];
static volatile bool slave_has_register_set = false;
volatile uint8_t txbuffer[TX_BUFFER_SIZE];
volatile uint8_t rxbuffer[RX_BUFFER_SIZE];
void i2c_init(uint8_t address); void i2c_slave_init(uint8_t address);
void i2c_stop(void); void i2c_slave_stop(void);
ISR(TWI_vect);
#endif // I2C_SLAVE_H #endif // I2C_SLAVE_H

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@ -197,9 +197,9 @@ uint8_t matrix_scan(void)
# endif # endif
if (USB_DeviceState != DEVICE_STATE_Configured){ if (USB_DeviceState != DEVICE_STATE_Configured){
txbuffer[1] = 0x55; i2c_slave_reg[1] = 0x55;
for (uint8_t i = 0; i < MATRIX_ROWS; i++){ for (uint8_t i = 0; i < MATRIX_ROWS; i++){
txbuffer[i+2] = matrix[i]; //send matrix over i2c i2c_slave_reg[i+2] = matrix[i]; //send matrix over i2c
} }
} }
@ -398,7 +398,7 @@ static void unselect_cols(void)
void matrix_setup(void){ void matrix_setup(void){
if (USB_DeviceState != DEVICE_STATE_Configured){ if (USB_DeviceState != DEVICE_STATE_Configured){
i2c_init(SLAVE_I2C_ADDRESS); //setup address of slave i2c i2c_slave_init(SLAVE_I2C_ADDRESS); //setup address of slave i2c
sei(); //enable interupts sei(); //enable interupts
} }
} }

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@ -197,9 +197,9 @@ uint8_t matrix_scan(void)
# endif # endif
if (USB_DeviceState != DEVICE_STATE_Configured){ if (USB_DeviceState != DEVICE_STATE_Configured){
txbuffer[1] = 0x55; i2c_slave_reg[1] = 0x55;
for (uint8_t i = 0; i < MATRIX_ROWS; i++){ for (uint8_t i = 0; i < MATRIX_ROWS; i++){
txbuffer[i+2] = matrix[i]; //send matrix over i2c i2c_slave_reg[i+2] = matrix[i]; //send matrix over i2c
} }
} }
@ -398,7 +398,7 @@ static void unselect_cols(void)
void matrix_setup(void){ void matrix_setup(void){
if (USB_DeviceState != DEVICE_STATE_Configured){ if (USB_DeviceState != DEVICE_STATE_Configured){
i2c_init(SLAVE_I2C_ADDRESS); //setup address of slave i2c i2c_slave_init(SLAVE_I2C_ADDRESS); //setup address of slave i2c
sei(); //enable interupts sei(); //enable interupts
} }
} }

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@ -197,9 +197,9 @@ uint8_t matrix_scan(void)
# endif # endif
if (USB_DeviceState != DEVICE_STATE_Configured){ if (USB_DeviceState != DEVICE_STATE_Configured){
txbuffer[1] = 0x55; i2c_slave_reg[1] = 0x55;
for (uint8_t i = 0; i < MATRIX_ROWS; i++){ for (uint8_t i = 0; i < MATRIX_ROWS; i++){
txbuffer[i+2] = matrix[i]; //send matrix over i2c i2c_slave_reg[i+2] = matrix[i]; //send matrix over i2c
} }
} }
@ -398,7 +398,7 @@ static void unselect_cols(void)
void matrix_setup(void){ void matrix_setup(void){
if (USB_DeviceState != DEVICE_STATE_Configured){ if (USB_DeviceState != DEVICE_STATE_Configured){
i2c_init(SLAVE_I2C_ADDRESS); //setup address of slave i2c i2c_slave_init(SLAVE_I2C_ADDRESS); //setup address of slave i2c
sei(); //enable interupts sei(); //enable interupts
} }
} }