Hei,
I've been using ADCPi to read values off an Alphasense AFE for years. Suddenly, reading has become unstable. I've seen this before when temperature has been close to 60C. In this case, temperature is only 50C and it has been stable at this temperature before.
i2cdetect -y 1 reports both channels working so no error there.
Suggestions?
Error reproduction:
Channel 1: 1.934793
Channel 2: 1.969387
Channel 3: 0.516439
Traceback (most recent call last):
File "./demo_readvoltage.py", line 61, in <module>
main()
File "./demo_readvoltage.py", line 51, in main
print("Channel 4: %02f" % adc.read_voltage(4))
File "../ADCPi.py", line 140, in read_voltage
raw = self.read_raw(channel)
File "../ADCPi.py", line 187, in read_raw
__adcreading = self.__bus.read_i2c_block_data(address, config, 4)
IOError: [Errno 121] Remote I/O error
IOError: [Errno 121] Remote I/O error
542 Views - Created 25/08/2022
25/08/2022
Posted by:
taarhaug
25/08/2022
Posted by:
andrew
Location:
United Kingdom
Hi
The temperature range of the MCP3424 ADC used on the ADC Pi is -40°C to +125°C so it should be well within range at 60°C.
Do you get the same problem when reading from the second ADC on pins 5 to 8 or just on the first ADC? If the problem only occurs on one ADC then that would suggest a problem with that ADC, if it happens on both then the problem is somewhere between the ADCs and the Raspberry Pi.
A remote I/O error means the Raspberry Pi is having trouble communicating with the ADC Pi so if the problem is only happening at high temperatures one possible cause is a dry joint on one of the solder connections. If there is a dry joint or loose connection when the metal in the connectors heats up it could expand breaking the connection across the joint.
Try reflowing the solder on the 40-pin header and the address select header. Hopefully, this will fix the problem.
The temperature range of the MCP3424 ADC used on the ADC Pi is -40°C to +125°C so it should be well within range at 60°C.
Do you get the same problem when reading from the second ADC on pins 5 to 8 or just on the first ADC? If the problem only occurs on one ADC then that would suggest a problem with that ADC, if it happens on both then the problem is somewhere between the ADCs and the Raspberry Pi.
A remote I/O error means the Raspberry Pi is having trouble communicating with the ADC Pi so if the problem is only happening at high temperatures one possible cause is a dry joint on one of the solder connections. If there is a dry joint or loose connection when the metal in the connectors heats up it could expand breaking the connection across the joint.
Try reflowing the solder on the 40-pin header and the address select header. Hopefully, this will fix the problem.
25/08/2022
Posted by:
taarhaug
Hei,
I tried both
adc = ADCPi(0x68, 0x68, 12)
adc = ADCPi(0x69, 0x69, 12)
if that's what you are asking. It did not make a difference.
I will check the soldering.
Thor
I tried both
adc = ADCPi(0x68, 0x68, 12)
adc = ADCPi(0x69, 0x69, 12)
if that's what you are asking. It did not make a difference.
I will check the soldering.
Thor
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