CAPACITIVE TOUCH HAT MPR121 NOT DETECTED IN RASPI 4? Moderators: adafruit_support_bill, adafruit

[chorzkie]

Hi everyone,
I'm trying to connect my Adafruit capacitive touch hat MPR121 to my Raspi 4, but still no luck. Anybody has experiences connecting it to Raspi 4?

About wiring, I extend the connection with GPIO extention cable like picture below. I'm quite sure it's correct, the red LED is on, but perhaps I make mistake here?


Then I follow all instructions on this page, https://learn.adafruit.com/circuitpytho ... 3030038-15
All successful, even Blinkatest.py runs well.




However, my Raspi4 seems still not detect it.


Running a simple python code as below results in error.

Code: Select all | TOGGLE FULL SIZE

import time
import board
import busio
import adafruit_mpr121


i2c = busio.I2C(board.SCL, board.SDA)
mpr121 = adafruit_mpr121.MPR121(i2c)

while True:
    if mpr121[0].value:
        print("Pin 0 touched!")


Can anybody please help, what have I missed? Or point my mistake.
Thanks in advance.

[kmm27]

Sadly I don't have an answer for you, but came here because I'm having the exact same problem! Only, I'm not using the hat, but just directly wiring to the relevant GPIO pins.

[kmm27]

I LIED - I do have a fix :)

My SDA and SCL pins were swapped. I had guessed based on the tutorial images, but either guessed wrong or the docs are off for the latest versions.

[danhalbert]

@kmm27 what did you change, wiring or code? If the tutorial is wrong, we would like to fix it, of course.

@chorzkie did you get it working? Looking at your photo, it is not clear that the header pins are soldered to the board; are they? It may be a push-fit but the connections will not be reliable.

[kmm27]

I just changed the wiring!