rtc_datetime_t
drv_ds1307_read(void)
{
uint8_t ds1307_addr[] = {0x00};
twi_write_bytes(DS1307_I2C_ADDR, 1, ds1307_addr);
rtc_datetime_t data;
twi_read_bytes(DS1307_I2C_ADDR, sizeof(rtc_datetime_t), (uint8_t *) (&data));
data.seconds &= 0x7F;
data.hours &= 0x3F;
return data;
}
void
drv_ds1307_start(void)
{
uint8_t data [2];
data[0] = 0x00;
/* Timekeeper Registers address */
twi_write_bytes(DS1307_I2C_ADDR, 1, &data[0]);
twi_read_bytes(DS1307_I2C_ADDR, 1, &data[1]);
data[1] &= 0x7F;
/* Clear CH (enable clock generator) */
twi_write_bytes(DS1307_I2C_ADDR, 2, (uint8_t *)&data);
}
void
drv_ds1307_stop(void)
{
uint8_t data [2];
data[0] = 0x00;
/* Timekeeper Registers address */
twi_write_bytes(DS1307_I2C_ADDR, 1, &data[0]);
twi_read_bytes(DS1307_I2C_ADDR, 1, &data[1]);
data[1] |= 0x80;
/* Set CH (disable clock generator) */
twi_write_bytes(DS1307_I2C_ADDR, 2, (uint8_t *)&data);
}
/* Writes num bytes starting from regAddrStart. Each subsequent byte will be written to the register above (newRegPtr = oldRegPtr + 1). Respects regMasks.
*
* 76543210
* 00010100 value[n] to write
* 00011100 mask[n] byte
* 01101101 original register[regAddrStart + n]
* 01100001 original & ~mask
* 01110101 masked | value
*
* Input: regAddrStart The register address to start reading bytes from
* data Pointer to data to be written
* regMasks Pointer to byte masks for each register
* num The number of registers to be read
* Return: 0 Succeeded
* >0 Failed, see handle_error() for relavant error codes
*/
uint8_t twi_write_bits(uint8_t regAddrStart, uint8_t *data, uint8_t *regMasks, uint8_t num) {
uint8_t i;
uint8_t buffer[num];
twi_read_bytes(regAddrStart, buffer, num);
for(i = 0; i < num; i++) {
data[i] &= regMasks[i];
buffer[i] &= ~regMasks[i];
buffer[i] |= data[i];
}
twi_write_bytes(regAddrStart, buffer, num);
return 0;
}
void
drv_ds1307_write(const rtc_datetime_t rtc_datetime)
{
struct {
uint8_t address;
rtc_datetime_t datetime;
} data;
data.address = 0x00;
data.datetime = rtc_datetime;
/* Keep CH (clock enable) bit as it set */
uint8_t ch;
/* Timekeeper Registers address */
uint8_t ds1307_addr[] = { 0x00 };
twi_write_bytes(DS1307_I2C_ADDR, 1, ds1307_addr);
twi_read_bytes(DS1307_I2C_ADDR, 1, &ch);
ch &= 0x80;
data.datetime.seconds |= ch;
twi_write_bytes(DS1307_I2C_ADDR, sizeof(data), (uint8_t *)&data);
}