I2C multiple write

[espruino-discuss]

Posted at 2020-04-13 by Abhigkar

Hi there,

I am in a process to write Espruino compatible module for Si114x Pulse sensor library which is basically a code conversion on Arduino library. The sensor uses I2C protocol for MCU comuniication.

I know that Espruino supports byte array in I2C.writeTo() method, and also stop:false/true option.

So if I would need to convert the below code what should be the best option for me?

void PulsePlug<T>::writeParam(uint8_t addr, uint8_t val)
{
   // write to parameter ram
   _i2c->beginTransmission(i2cAddr);
   _i2c->write(Si114x::PARAM_WR);
   _i2c->write(val);
   // auto-increments into Si114x::COMMAND
   _i2c->write(0xA0 | addr);   // PARAM_SET
   _i2c->endTransmission();
   delay(10);   // XXX Nothing in datasheet indicates this is required; was in
                // original code.
}


uint8_t PulsePlug<T>::readParam(uint8_t addr)
{
   // read from parameter ram
   _i2c->beginTransmission(i2cAddr);
   _i2c->write(Si114x::COMMAND);
   _i2c->write(0x80 | addr);   // PARAM_QUERY
   _i2c->endTransmission();
   delay(10);   // NOTE: Nothing in datasheet indicates this is required - in original code.
   return getReg(Si114x::PARAM_RD);
}

uint8_t PulsePlug<T>::getReg(uint8_t reg)
{
   // get a register
   _i2c->beginTransmission(i2cAddr);
   _i2c->write(reg);
   _i2c->endTransmission();
   requestData(1);
   uint8_t result = _i2c->read();
   delay(10);   // NOTE: Nothing in datasheet indicates this is required - in original code.
   return result;
}

1- Combine all bytes to single byte array?
2- Individual writeTo() call having stop:false for the first call?
3- How should I care the delay, a setTimeout/ Promise?

Reference:
Si114x datasheet
Arduino Library

[espruino-discuss]

Posted at 2020-04-13 by @MaBecker

Take a look into this module

https://github.com/espruino/EspruinoDocs/blob/master/devices/SSD1306.js