RAK11720 Analog signals


I’ve doing some tests with RAK11720 on my custom board, and I have a couple of questions regarding RAK11720 compatibility with:

  • VBat measurement:
    • Currently I’ve used the same resistor divider 1M/1.5M that RAK boards uses, but it’s not clear to me which port to use currently I have it on ADC3/PIN26/IO4 (probably incorrect). Also I see on another topic that probably I need to adapt the resistor divider.
  • Analog Input RAK5801
    • Is this module compatible with RAK11720? Appears to use ADC5/PIN31/AIN1_IN and ADC6/PIN32/AIN2_IN Correct?. Maybe here is neccessary to adapt the opamp resistors too?

Thanks in advance

RUI3 api.system.bat.get() is designed to work with the WisBlock Base Boards.

RUI3 uses for the battery voltage reading the ADC8 pin.

As you can see in the schematic, due to range limitations of the internal ADC, there is a second resistor divider with 300k/1M in addition to the 1M/1.5M.

RAK5801 will use AIN1, which is connected to ADC5 and WB_IO4, which is connected to ADC3.

Hello @beegee

I have now more or less clear, many thanks.

I see that with RAK11720 I can use three ADC’s at the same time? For example:

  • Battery Voltage on ADC8 Pin32
  • AIN0 from RAK5801 on ADC5 Pin31
  • AIN1 from RAK5801 on ADC4 Pin26

Should work, but I never tried it.