MCP9600 experience & I2C troubleshooting


#1

Anyone here used the MCP9600 to read Thermocouples? I’ve integrated three of these on an existing board that already had 7 I2C devices that have worked great for several years. The MCP9600 works perfectly by itself, but when used together with some the other devices, it will lock up the entire I2C bus. This in turn makes the machine crash in a rather bad way…


#2

@jenschr, does the MCP9600 share I2C addresses with any of the other seven devices?


#3

Yeah. I found the culprit by soldering som wires to the SCL and SDA lines and attaching my logic analyser. The clock and other signals from the MCP9600 looked correct, but they were not the same scale? Turns out the MCP9600 is 100Khz only, whereas all the other IC’s were 400Khz…

Who could know that could crash the entire bus? A first for me at least :slight_smile: