I’m working on getting my project, Modulo working with the Photon and have run into an issue with I2C. It seems like after an I2C write fails, the bus locks up and won’t transmit again. Both SDA and SCL are held low rather than returning to idle (high) as they should. I created this trivial test cas…

Hey all. I finally got back around to testing this. I wasn’t sure if this fix is in any release branches, so I decided to try the develop branch. Unfortunately, after getting my local firmware build working with the develop branch it still doesn’t appear work. I’m getting the same behavior as befor…

I did a little more digging. I think the problem is that it’s stuck waiting for the “master transmitter mode selected” event but instead we get a “slave ack failure” event. I tried coding a fix and it seems to address the immediate problem, though I’m not sure if the return values are correct (coul…

@modulo , did you see the STM32F20x I2C errata: STM32F2’s I2C limitation(from ERRATA): 1)Start cannot be generated after a misplaced STOP 2)Mismatch on the “Setup time for a repeated Start condition” timing parameter I suspect you may be seeing condition 1) and the only solution is a soft reset…

I hadn’t seen that, @peekay123 . Thank you for sharing. Hmmm.

@modulo , for your convenience, here is the link .

I tried the new release candidate and it works much better. I actually got the photon discovering and controlling Modulos for the first time. Yay! Even better, it seems quite solid in the face of bus errors. Hot plugging works now too! However, there is still an issue. After a slave address has bee…

[image] modulo: I believe the fix should be similar to what I did in the change above: while waiting for MASTER_RECEIVER_MODE_SELECTED, check to see if the slave address ack failed. If it did, bail immediately rather than waiting for a timeout. That said, when I tried my change in the new latest…

Hey @BDub and @satishgn . I was wondering if you had a chance to look into setting a flag instead of timing out? It sounds liked a reasonable solution but I haven’t had a chance to try it yet.

Issue with I2C on Photon

Troubleshooting

mdma August 17, 2015, 8:36pm 43

Hey all! A new release candidate is available that brings greater reliability to the I2C interface. Particle Firmware Updates Thread

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Issue with I2C on Photon

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