At my company, I am working on a project using 4 COM-16566 Qwiic Quad Relays and a PAC1934 on a shared I2C bus controlled by a Raspberry Pi. I have had recurring problems with the COM-16566 boards no longer responding to I2C commands and not being detectable with ‘i2cdetect’. This seems to be a common problem for both the solid-state and conventional relays, judging from the comments on the product page and threads on this forum. The issue seems to occur when the boards are power cycled. We have observed it on 5 of our boards so far. We are using our boards with the DC-DC converter bypassed and powered directly with both 5V and 3.3V.
Other threads I have seen:
viewtopic.php?f=105&t=59849&p=242816&hi … ay#p242816
viewtopic.php?f=105&t=50806&p=207512&hi … re#p207512
viewtopic.php?f=105&t=56214&p=228117&hi … re#p228117
So far, I have tried:
The Raspberry Pi that I have used for testing and in the project can detect single quad relay boards (through a single Sparkfun female-header-to-qwiic connector cable) that are not experiencing this issue that are in the same hardware configuration as those that are, so I do not believe that there is a problem with the Pis or our I2C bus.
There appears to be nothing physically wrong with the boards. The voltage levels on the relays, the MCU, and the I2C bus are as expected.
My remaining hypothesis is that something (possibly a clock or power glitch) has caused the MCU to erase its firmware.
Purchasing more boards isn’t an issue but it would be nice if we could get 5 more of these running without having to buy more when they seem to be in such relatively short supply.
We are operating in Canada and we purchased these boards several months ago from Digikey.ca, so I am not sure about whether your return policy is applicable.
We likely have all of the required programming hardware at our workplace if you could share the instructions.
All the best,
Sophie Bernier, EIT