EZ Make Oven Issues with MCP9600

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CroyToneAudio
 
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Joined: Tue Sep 13, 2022 2:03 am

EZ Make Oven Issues with MCP9600

Post by CroyToneAudio »

Hello,

I am trying top put together the EZ Make Oven project and I realized after the fact that in the MCP9600 documentation it says that

"MCP960x devices do not work properly with the current CircuitPython I2C support on ESP32-S2 and -S3 boards. This problem is under investigation"

The current PyPortal that im using has the ESP32 wifi chip and so i'm a little stuck.

I'm currently running CircuitPython 7.3.3 and I was just trying to set up the probe to take reading using one of the example codes from the MCP9600 guide.

Code: Select all

import board
import busio
from adafruit_bus_device.i2c_device import I2CDevice
from adafruit_mcp9600 import MCP9600

i2c = busio.I2C(board.SCL, board.SDA,frequency=100000)
try:
    # using default I2C register and "K" thermocouple
    device = MCP9600(i2c)
    print("temperature(C):",device.temperature)
except ValueError:
    print("MCP9600 sensor not detected")
After running this, I got the error
"Traceback (most recent call last):
File "code.py", line 9, in <module>
File "adafruit_mcp9600.py", line 236, in __init_
_
OSError: [Errno 5] Input/Output error"

What i'm asking is am I basically stuck until this problem gets resolved? is there a fix for this that I haven't found? Am I able to use a different thermocouple amplifier with this setup and have it work as intended?

thanks very much for any information you can give me! I'm still fairly new to coding on hardware and I would love to get this project up and running!

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mikeysklar
 
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Re: EZ Make Oven Issues with MCP9600

Post by mikeysklar »

Are you running the latest 7.x library bundle for the MCP9600? It looks like a patch was put in as of May 22 to disable probing which appears to be linked to the ESP32 issue.

https://github.com/adafruit/Adafruit_Ci ... 00/pull/20
https://github.com/adafruit/circuitpython/pull/6366

If the current library is not working can you try withe 8.x beta of CircuitPython and library bundle?

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CroyToneAudio
 
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Re: EZ Make Oven Issues with MCP9600

Post by CroyToneAudio »

I tried running the thermocouple program with both the latest version of CircuitPython and it's library and the 8.x beta version and its library and its giving me the same issues. The page for the MXP9600 linked this issue to this

https://github.com/adafruit/circuitpython/issues/6311

looks like it's an issue that has yet to be resolved. Does anyone know if I could use a different thermocouple amplifier in this project to achieve the same results?

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mikeysklar
 
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Re: EZ Make Oven Issues with MCP9600

Post by mikeysklar »

There is no drop in replacement thermocouple amp with the EZ Make oven solution, but there are two boards you could consider.

1) Probably going to be the same issue based on the guide warnings, but there is a new MCP9601 that uses the MCP9600 same driver. You should probably try the 20 kHz suggestion on your MCP9600 and see if you get any change first.
If you're running into other issues with your MCP9601 connecting to your non-SAMD microcontroller, consider changing the frequency to 20000 as a possible fix. SAMD-based microcontrollers MUST use 100kHz frequency or higher.
https://www.adafruit.com/product/5165

2) The MAX31855 is SPI based, but would be a good alternative.

https://www.adafruit.com/product/269

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adafruit2
 
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Re: EZ Make Oven Issues with MCP9600

Post by adafruit2 »

note the pyportal uses an ESP32 but as an SPI peripheral - the main chip is a SAMD51 and works just fine.
that said, the MCP960x's are not great chips, try 50000 (50khz) or 200000 (200khz) as the frequency?

you may also want to cut the I2C voltage trace from 5V and set it to 3V
https://learn.adafruit.com/adafruit-pyp ... or-3020489

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CroyToneAudio
 
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Re: EZ Make Oven Issues with MCP9600

Post by CroyToneAudio »

Thank you for the Reply!

The first thing I did before I started trying to write the code was cutting the 5v trace on the Pyportal. It kept freezing up on boot and that solved that problem. As for frequencies, I've tried many frequencies on it with the same bad results. at 50kHz, it says its an invalid frequency and at 200kHz its still having the I/O error.

I think ill just have to figure out a different solution for the thermocouple problem in the mean time instead using this chip unless it's figured out soon. Its a cool project and I have some work that would benefit from its use greatly haha.

thanks!

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