diff options
Diffstat (limited to 'drivers/avr/i2c_slave.c')
-rwxr-xr-x | drivers/avr/i2c_slave.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/drivers/avr/i2c_slave.c b/drivers/avr/i2c_slave.c index 27696ca01a..18a29a45a5 100755 --- a/drivers/avr/i2c_slave.c +++ b/drivers/avr/i2c_slave.c @@ -9,23 +9,26 @@ #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 TWAR = (address << 1); // set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN); } -void i2c_stop(void){ +void i2c_slave_stop(void){ // clear acknowledge and enable bits TWCR &= ~((1 << TWEA) | (1 << TWEN)); } ISR(TWI_vect){ uint8_t ack = 1; - // temporary stores the received data - //uint8_t data; - + switch(TW_STATUS){ case TW_SR_SLA_ACK: // The device is now a slave receiver @@ -38,13 +41,13 @@ ISR(TWI_vect){ if(!slave_has_register_set){ buffer_address = TWDR; - if (buffer_address >= RX_BUFFER_SIZE){ // address out of bounds dont ack - ack = 0; - buffer_address = 0; + if (buffer_address >= I2C_SLAVE_REG_COUNT) { // address out of bounds dont ack + ack = 0; + buffer_address = 0; } slave_has_register_set = true; // address has been receaved now fill in buffer } else { - rxbuffer[buffer_address] = TWDR; + i2c_slave_reg[buffer_address] = TWDR; buffer_address++; } break; @@ -52,7 +55,7 @@ ISR(TWI_vect){ case TW_ST_SLA_ACK: case TW_ST_DATA_ACK: // This device is a slave transmitter and master has requested data - TWDR = txbuffer[buffer_address]; + TWDR = i2c_slave_reg[buffer_address]; buffer_address++; break; @@ -63,6 +66,6 @@ ISR(TWI_vect){ 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); }
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