Max32 Analog Input Chan 12

[TomK]

I have problem with analogRead(12).  When I setup a digital channel as below:

   pinMode(42, OUTPUT);
   digitalWrite(42, LOW);

The analog input stops working and always reads about 500 mV. 

The analog input has 910 ohms between pin and 3V3 and 1k between pin and gnd.  In some cases the 1K is open and all the pin sees is 3V3.

Using latest version Digilent MPIDE 0150.

 

[jpeyron]

Hi @TomK,

We were able to some what duplicate your issue with analog 12 when using digital pin 42 ( we did not use the pull up or pull down resistors ). Here is the reference manual for the MAX32. On page 12 at the bottom of the second page of the Pinout Table by Logical Pin Number is shows that pin 42 also is connected to AN12 which is Analog 12. I used both MPIDE and Arduino with the same results. If you are able to use a different digital pin or a different analog pin you should not have an issue. I verified using analog pin 12 and digital pin 43. My Arduino code currently is set to digital pin 43. Also I am not sure why you are using pull up and pull down resistors in your circuit?

cheers,

Jon

 

max32_things.pde

max32_stuff.ino