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No I2C Device at Address
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No I2C Device at Address

by agent6ca on Mon Jun 07, 2021 1:25 am

Apologies if this has been asked and answered, but Google has not been my friend on this one tonight.

I've got a Pi-3 and am trying to setup a TSL2591 sensor under python and keep getting an error message. (Actually same error message with an ADS1115 as well.) I've enabled I2C on the Pi and can see both devices from the command line using i2cdetect:
Screenshot from 2021-06-06 23-08-15.png
i2cdetect results
Screenshot from 2021-06-06 23-08-15.png (147.47 KiB) Viewed 155 times


I can also see the devices using i2c.scan() from within python:
Screenshot from 2021-06-06 23-11-31.png
i2c.scan() results
Screenshot from 2021-06-06 23-11-31.png (123.48 KiB) Viewed 155 times


However, any time I try to create the sensor object, I get an error that No I2C device is found at the address - despite having been found using i2c.scan():
Screenshot from 2021-06-06 23-13-28.png
sensor results
Screenshot from 2021-06-06 23-13-28.png (545.49 KiB) Viewed 155 times


I'm seeing the same results whether running python as a regular user or as root and regardless of what device I'm trying to use (TSL2591 or the ADS1115). I had the unit offline over the winter and finally getting around to updating the project, but something has clearly changed. Running Raspbian Buster, fresh install and fully updated as of this evening.

Anyone able to point me in the right direction on this?

Thanks!
Corey

agent6ca
 
Posts: 6
Joined: Thu Mar 26, 2015 10:04 pm

Re: No I2C Device at Address

by agent6ca on Mon Jun 07, 2021 2:53 pm

Still no luck getting this working but a quick update with some additional detail / steps:

1. Tried a fresh install of Adafruit CircuitPython and Blinka, following the steps outlined here: https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/installing-circuitpython-on-raspberry-pi

2. Confirmed I am using a 32-bit version of Raspbian - or at least that the SHA256 hash of the image I installed matches the hash of the 32-bit Raspbian image on the download site.

3. Tried changing the I2C clock speed to 10 kHz and 1 kHz as outlined in the install guide: https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/i2c-clock-stretching

4. Disconnected the ADS1115 so that only the Adafruit TSL2591 chip is connected.

There must be something I'm missing???

Corey

agent6ca
 
Posts: 6
Joined: Thu Mar 26, 2015 10:04 pm

Re: No I2C Device at Address

by agent6ca on Mon Jun 07, 2021 8:20 pm

Finally got this working. Tore out the strip board I had as an intermediate connector and wired the TSL2591 directly to the GPIO header. Means I have to give up the ADS1115 but that was really only used for an LDR as crude dark/light indicator anyway. The TSL2591 really out-does that in every way so will just adapt my code and abandon the LDR.

Screenshot from 2021-06-07 18-16-10.png
Finally working!
Screenshot from 2021-06-07 18-16-10.png (173.04 KiB) Viewed 125 times


Looks like the wiring on the daughterboard I was using to connect multiple devices in my enclosure was just enough to let the pi see it was there, but not good enough for a reading. Hopefully some help for the next guy who finds this on Google.

Now on to the next challenge.

Corey

agent6ca
 
Posts: 6
Joined: Thu Mar 26, 2015 10:04 pm

Please be positive and constructive with your questions and comments.