Beaglebone AI - read analog input with python

davavru · July 3, 2020, 3:02pm

Hello, i have a Beaglebone AI, i need read analog input with python code, example:

`

import Adafruit_BBIO.ADC as ADC
from time import sleep

ADC.setup()

analogPin = “P9_33”

while(1):
potVal = ADC.read(analogPin)
potVolt = potVal*1.8
print (“The Potentiometer Voltage is: {}”.format(potVolt))
sleep(0.5)

`

but, this code generated error:

debian@beaglebone:~$ sudo python3 test_bbai_ai.py
Traceback (most recent call last):
File “test_bbai_ai.py”, line 4, in
ADC.setup()
RuntimeError: Unable to setup ADC system. Possible causes are:

A cape with a conflicting pin mapping is loaded
A device tree object is loaded that uses the same name for a fragment: helper

Please, help me, thank you.

PD. BeagleBoard.org Debian Buster IoT TIDL Image 2020-04-06

Dennis_Bieber · July 3, 2020, 6:39pm

Hello, i have a Beaglebone AI, i need read analog input with python code,
example:

import Adafruit_BBIO.ADC as ADC

The first thing to realize is that the BB AI does not support runtime
pin-mux changes. There is no config-pin tool available. The second is that,
due to some changes in Px_y assignments to chip "balls", Adafruit_BBIO may
not be compatible.

ADC.setup()
RuntimeError: Unable to setup ADC system. Possible causes are:
- A cape with a conflicting pin mapping is loaded
- A device tree object is loaded that uses the same name for a fragment:

As stated -- the loaded device tree does not have pins configured for
ADC mode (hopefully it doesn't require all potential ADCs to be set, and
can find those that are active)

Please, help me, thank you.

You are going to have to edit the device tree source to define the
desired pin as analog input, compile it, and set up uEnv.txt to load this
device tree in place of the one that is already in place.

NOTE: I don't know if it is possible to provide just an overlay device tree
without modifying the primary device tree. Maybe start with
https://www.element14.com/community/community/project14/visionthing/blog/2019/11/16/beagleboard-ai-brick-recovery-procedure#jive_content_id_PINMUXING
or

which is a replacement for Adafruit_BBIO (no ADC.setup() in the example

github.com

MalavPatel3501/BeagleBone-AI--mpBBAI-IO-Python-Library/blob/master/mpBBAI-ADC.py

#/**************************************************************************************/
#/*File : mpBBAI-GPIO.py                                                               */
#/*Made by: Malav Patel                                                                */
#/*Company: Teksun Microsys Pvt Ltd                                                    */
#/*Topic:                                                                              */
#/*                                                                                    */
#/*       BBAI ADC Pin Read Sample Code                                                */
#/*                                                                                    */
#/*E-Mail Id: malav.patel@teksun.in                                                    */
#/**************************************************************************************/  

from  mpBBAIIO import*
import time

GPIO = mpBBAIGpio()

ADC_1 = "P9_33"
ADC_2 = "P9_35"

while True:

This file has been truncated. show original

as it is set up in device tree). Looking at the main file, it performs
everything through sysfs access.

Note that

github.com/adafruit/adafruit-beaglebone-io-python

Add support for BeagleBone AI with Adafruit BBIO.GPIO

opened 06:28AM - 25 Oct 19 UTC

jomoengineer

enhancement help wanted

The new BeagleBone AI has a AM57x processor and a different gpio mapping than th…e previous BeagleBone boards, thus the BBIO GPIO Python libs do not work properly on the BB AI. Ex: On the BB AI P9_15 is mapped to gpio76 where On the BB Black, P8_39 is mapped to gpio76 Also, although not really a Adafruit issue, the config-pin tool does not work with the BB AI: <pre><code> $ config-pin -q P9_15 P9_15 pinmux file not found! Pin has no cape: P9_15 </pre></code>

indicates the Adafruit_BBIO is not yet compatible with the BB AI.

Mark_Lazarewicz · July 3, 2020, 8:41pm

Hello Daveru

Please tell The professor Or H1B boot camp instructor he’s given you an assignment thats not possible.
If he doesn’t know that how’s he going to coach you after you add BBAI on your resume. Besides there’s no travel right now.
We understand tracking down Runtime errors is a tremendous task hopefully someone is available 24/7 in the future when you get another runtime error
Where are you going to school?

dhruvag2000 · October 23, 2021, 7:19am

I am aware that this post clearly asks for reading analog inputs with python, however I am pasting a solution in C which I believe can very easily be written in python as it’s very basic file I/O: