Lavanya rajan
Well-known member
I have designed a PCB which has following functionalities
4 channel PT100 RTD Temperature sensor reading (MAX31865 based)
4 channel Thermocouple reading (MAX31855 based )
W5500 SPI Ethernet module for internet connectivity, all these modules are connected to teensy 4.0 through SPI interface
the modules were working perfectly on PCB but only for quite sometime, but after certain time these modules are not working properly, though cross checked wirings and voltage levels, everything seems to be fine, but still facing this strange problem.
RTD shows 982C randomly
Reading from PT100 Temperature Sensors
PT100 Temperature1 = 988.79°C
PT100 Temperature2 = 988.79°C
PT100 Temperature3 = 988.79°C
PT100 Temperature4 = 988.79°C
Fault 0xFF
RTD High Threshold
RTD Low Threshold
REFIN- > 0.85 x Bias
REFIN- < 0.85 x Bias - FORCE- open
RTDIN- < 0.85 x Bias - FORCE- open
Under/Over voltage
Thermocouple shows
Thermocouple fault(s) detected!
FAULT: Thermocouple is open - no connections.
FAULT: Thermocouple is short-circuited to GND.
FAULT: Thermocouple is short-circuited to VCC.
Not sure what is the issue, any help on this is greatly appreciated.. thanks in advance
4 channel PT100 RTD Temperature sensor reading (MAX31865 based)
4 channel Thermocouple reading (MAX31855 based )
W5500 SPI Ethernet module for internet connectivity, all these modules are connected to teensy 4.0 through SPI interface
the modules were working perfectly on PCB but only for quite sometime, but after certain time these modules are not working properly, though cross checked wirings and voltage levels, everything seems to be fine, but still facing this strange problem.
RTD shows 982C randomly
Reading from PT100 Temperature Sensors
PT100 Temperature1 = 988.79°C
PT100 Temperature2 = 988.79°C
PT100 Temperature3 = 988.79°C
PT100 Temperature4 = 988.79°C
Fault 0xFF
RTD High Threshold
RTD Low Threshold
REFIN- > 0.85 x Bias
REFIN- < 0.85 x Bias - FORCE- open
RTDIN- < 0.85 x Bias - FORCE- open
Under/Over voltage
Thermocouple shows
Thermocouple fault(s) detected!
FAULT: Thermocouple is open - no connections.
FAULT: Thermocouple is short-circuited to GND.
FAULT: Thermocouple is short-circuited to VCC.
Not sure what is the issue, any help on this is greatly appreciated.. thanks in advance