uint8_t ICACHE_FLASH_ATTR
twi_readFrom(uint8_t address, uint8_t *buf, unsigned int len,
uint8_t sendStop)
{
unsigned int i;
if (!twi_write_start()) {
serial_print("I2C: bus busy\r\n");
return 4;
}
if (!twi_write_byte(((address << 1) | 1) & 0xFF)) {
if (sendStop)
twi_write_stop();
serial_print("I2C: received NACK on transmit of address\r\n");
return 2;
}
for (i = 0; i < (len - 1); i++)
buf[i] = twi_read_byte(false);
buf[len - 1] = twi_read_byte(true);
if (sendStop)
twi_write_stop();
i = 0;
while (SDA_READ() == 0 && (i++) < 10) {
SCL_LOW();
twi_delay(twi_dcount);
SCL_HIGH();
twi_delay(twi_dcount);
}
return 0;
}
uint8_t ICACHE_FLASH_ATTR
twi_writeTo(uint8_t address, uint8_t *buf, unsigned int len,
uint8_t sendStop)
{
unsigned int i;
if (!twi_write_start()) {
serial_print("I2C: bus busy\r\n");
return 4;
}
if (!twi_write_byte(((address << 1) | 0) & 0xFF)) {
if (sendStop)
twi_write_stop();
serial_print("I2C: received NACK on transmit of address\r\n");
return 2;
}
for (i = 0; i < len; i++) {
if (!twi_write_byte(buf[i])) {
if (sendStop)
twi_write_stop();
serial_print("I2C: received NACK on transmit of data\r\n");
return 3;
}
}
if (sendStop)
twi_write_stop();
i = 0;
while (SDA_READ() == 0 && (i++) < 10) {
SCL_LOW();
twi_delay(twi_dcount);
SCL_HIGH();
twi_delay(twi_dcount);
}
return 0;
}
static bool twi_read_bit(void) {
uint32_t i = 0;
SCL_LOW();
SDA_HIGH();
twi_delay(twi_dcount+2);
SCL_HIGH();
while (SCL_READ() == 0 && (i++) < twi_clockStretchLimit);// Clock stretching
bool bit = SDA_READ();
twi_delay(twi_dcount);
return bit;
}
static bool twi_write_bit(bool bit) {
uint32_t i = 0;
SCL_LOW();
if (bit) SDA_HIGH();
else SDA_LOW();
twi_delay(twi_dcount+1);
SCL_HIGH();
while (SCL_READ() == 0 && (i++) < twi_clockStretchLimit);// Clock stretching
twi_delay(twi_dcount);
return true;
}
static bool twi_write_start(void) {
SCL_HIGH();
SDA_HIGH();
if (SDA_READ() == 0) {
return false;
}
twi_delay(twi_dcount);
SDA_LOW();
twi_delay(twi_dcount);
return true;
}
static bool ICACHE_FLASH_ATTR twi_read_bit()
{
unsigned int i = 0;
SCL_LOW();
SDA_HIGH();
twi_delay(twi_dcount + 2);
SCL_HIGH();
while (SCL_READ() == 0 && (i++) < twi_clockStretchLimit); // Clock stretching
bool bit = SDA_READ();
twi_delay(twi_dcount);
return bit;
}
static bool twi_write_stop(void){
uint32_t i = 0;
SCL_LOW();
SDA_LOW();
twi_delay(twi_dcount);
SCL_HIGH();
while (SCL_READ() == 0 && (i++) < twi_clockStretchLimit); // Clock stretching
twi_delay(twi_dcount);
SDA_HIGH();
twi_delay(twi_dcount);
return true;
}
static bool ICACHE_FLASH_ATTR twi_write_start(void)
{
SCL_HIGH();
SDA_HIGH();
if (SDA_READ() == 0) {
serial_printf("twi write start sda read false\r\n");
return false;
}
twi_delay(twi_dcount);
SDA_LOW();
twi_delay(twi_dcount);
return true;
}
static bool ICACHE_FLASH_ATTR twi_write_stop(void)
{
unsigned int i = 0;
SCL_LOW();
SDA_LOW();
twi_delay(twi_dcount);
SCL_HIGH();
while (SCL_READ() == 0 && (i++) < twi_clockStretchLimit); // Clock stretching
twi_delay(twi_dcount);
SDA_HIGH();
twi_delay(twi_dcount);
return true;
}
void ICACHE_RAM_ATTR twi_stop(void)
{
// send stop condition
//TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTO);
SCL_HIGH(); // _BV(TWINT)
twi_ack = 1; // _BV(TWEA)
twi_delay(5); // Maybe this should be here
SDA_HIGH(); // _BV(TWSTO)
// update twi state
twi_state = TWI_READY;
}
unsigned char twi_readFrom(unsigned char address, unsigned char* buf, unsigned int len, unsigned char sendStop){
unsigned int i;
if(!twi_write_start()) return 4;//line busy
if(!twi_write_byte(((address << 1) | 1) & 0xFF)) {
if (sendStop) twi_write_stop();
return 2;//received NACK on transmit of address
}
for(i=0; i<(len-1); i++) buf[i] = twi_read_byte(false);
buf[len-1] = twi_read_byte(true);
if(sendStop) twi_write_stop();
i = 0;
while(SDA_READ() == 0 && (i++) < 10){
SCL_LOW();
twi_delay(twi_dcount);
SCL_HIGH();
unsigned int t=0; while(SCL_READ()==0 && (t++)<twi_clockStretchLimit); // twi_clockStretchLimit
twi_delay(twi_dcount);
}
return 0;
}
unsigned char twi_writeTo(unsigned char address, unsigned char * buf, unsigned int len, unsigned char sendStop){
unsigned int i;
if(!twi_write_start()) return 4;//line busy
if(!twi_write_byte(((address << 1) | 0) & 0xFF)) {
if (sendStop) twi_write_stop();
return 2; //received NACK on transmit of address
}
for(i=0; i<len; i++) {
if(!twi_write_byte(buf[i])) {
if (sendStop) twi_write_stop();
return 3;//received NACK on transmit of data
}
}
if(sendStop) twi_write_stop();
i = 0;
while(SDA_READ() == 0 && (i++) < 10){
SCL_LOW();
twi_delay(twi_dcount);
SCL_HIGH();
unsigned int t=0; while(SCL_READ()==0 && (t++)<twi_clockStretchLimit); // twi_clockStretchLimit
twi_delay(twi_dcount);
}
return 0;
}
