Using 12c to write to a 16 bit register

[boonsiong123]

Hi...I am using a 16bit ADC (ADS1115). I am trying to configure the ADC. However, the config register in ADS1115 is 16bit. The args in i2c_write allows up to a value of 255. Any way I can get around with this?

[Pi3rr3-aprisium]

Same problem here

[MrYsLab]

Thanks for the question. This is accomplished by converting the 16-bit value into two 8-bit values, an MSB and an LSB value. These values are written to the i2c device register.

This article explains how to split a 16-bit value into msb and lsb values using Python.

If you look at line 491 of Rob Tilaart's Arduino library for the device, you will see an example in an Arduino library.

Here is how this might be expressed in Telemetrix:

def write_16_bit_i2c(register, value):
    """
    Write a 16 value to an i2c register
    :param register: i2c register
    :param value: 16 bit value
    :return: None
    """
    msb = value >> 8
    lsb = value & 0xff
    my_board.i2c_write( i2c_device_address, [register,msb, lsb])

Please note that this is untested code, since I do not own the device.

Please let me know if this answers your question.

[Pi3rr3-aprisium]

Hey, here to update that what you sent is correct and working. We need to write to the board the read from it. thanks again for your help

[MrYsLab]

My pleasure to help. I am glad it is working.

[MrYsLab]

I just updated my answer since I don't believe it was correct. Again, this is not tested, so if you have any questions, please let me know.

[boonsiong123]

Thanks, I will give it a try