After updating my P1 to 0.4.3, I have most things working, including I2C where I’m reading a MCP3421 ADC. However, I’ve run into a small issue with the I2C connection: Sometimes it works, and sometimes it doesn’t work. I have my code setup to read data from the MCP3421 every second, so its well …

No worries got it working now, I had accidentally taken the wrong resistors. https://a248.e.akamai.net/f/1949/3326/8/www.blogcdn.com/massively.joystiq.com/media/2011/10/facepalm.jpg

Ok, I’m going to steer this discussion back to the I2C issue… :smile: @mdma , @BDub - I know this is being worked on, but do you guys have an estimated ETA for the fix or at least a proper workaround? I have everything working on my board, and this is the only issue holding it back, so it would be…

You can give this a try and see how things go: https://github.com/spark/firmware/commit/09dd8096774c74b6680ddb47b39fc21134df49a8

Not sure if this applies, but, I had an I2C connection problem when trying to add a magnetometer to a 6DOF IMU. I made the wiring as short as possible. The problem went away.

Hi Tim, Thanks for the info. The wires on my board are fairly short, so I don’t think that is the issue. Besides, it consistently doesn’t work until I reset the board, which makes me think it is a code issue.

For now with fixes, it would be accessible only if you compile locally.

Is there any new progress made? or was it just reversing the change that was made to try and fix the issue? calling I2C_GenerateSTOP(I2C1, ENABLE); was the “fix” that didn’t work (and made it worse), the original issue is still there…

@Hootie81 there were some changes here: https://github.com/spark/firmware/commit/09dd8096774c74b6680ddb47b39fc21134df49a8

Yeah, unfortunately that doesn’t fix the problem… that was reversing the attempted fix. I’ll continue to debug and see what else I can find… but I’m almost completely out of ideas :frowning:

I2C connection randomly fails on P1 & Photon

Troubleshooting

ElementOrange August 4, 2015, 12:30am 22

@kennethlimcp,

Thanks for this. How can I use this with my code?

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I2C connection randomly fails on P1 & Photon

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