Post a schematic.I have 6 3V reed relays (SIL03-1A72-71D) that connect to a raspberry pi pico directly via gpio pins 11, 12, 13, 14, 15, 18, and 19 on a custom pcb. The connections to the relays are: 1 is connected to 12V, 3 is connected to the pico, and 5 and 7 are grounded to a ground plane. The relays are meant to actuate a pinch valve. The pico is also connected to two Sparkfun MAX31855K thermocouple readers via spi using pins 2, 3, 5, and 6.
Currently, I can read from the thermocouple readers normally, but when I turn the 12V power on, the temperature that is read slowly drops from 21 to 0 and then 4091. The pinch valves still actuate normally and everything, but I cannot read the thermocouples normally. When I turn the 12V power off, the thermocouple immediately goes back to normal. What could be happening here?
Statistics: Posted by ame — Thu Dec 14, 2023 5:35 am