谢谢，看来是接触问题，插入拧紧后显示正常了
pi@raspberrypi:~/daqhats/examples/c/mcc118/single_value_read $ ./single_value_read
MCC 118 single data value read example
Function demonstrated: mcc118_a_in_read
Channels: 0 - 3
Options: OPTS_DEFAULT
Press 'Enter' to continue
Acquiring data ... Press 'Enter' to abort
Samples/Channel Channel 0 Channel 1 Channel 2 Channel 3
166 4.97113 V 1.74062 V 1.74109 V 1.74678 V
pi@raspberrypi:~/daqhats/examples/c/mcc118/single_value_read $ ./single_value_read
MCC 118 single data value read example
Function demonstrated: mcc118_a_in_read
Channels: 0 - 3
Options: OPTS_DEFAULT
Press 'Enter' to continue
Acquiring data ... Press 'Enter' to abort
Samples/Channel Channel 0 Channel 1 Channel 2 Channel 3
275 3.31255 V 1.74062 V 1.74109 V 1.74167 V
pi@raspberrypi:~/daqhats/examples/c/mcc118/single_value_read $ ./single_value_read
MCC 118 single data value read example
Function demonstrated: mcc118_a_in_read
Channels: 0 - 3
Options: OPTS_DEFAULT
Press 'Enter' to continue
Acquiring data ... Press 'Enter' to abort
Samples/Channel Channel 0 Channel 1 Channel 2 Channel 3
304 -0.00460 V 1.74062 V 1.74109 V 1.74678 V
刚升级了固件，没什么改善。
pi@raspberrypi:~/daqhats/tools $ ./mcc118_firmware_update 0 ~/daqhats/tools/MCC_118.hex
Checking versions...
Hex file firmware version 1.03
Device firmware version 1.01
Do you want to continue? Press Y to continue, any other key to exit. > y
Erasing...done
Writing...done
Verifying...done
Starting firmware...done
Checking device...firmware version 1.03
-----------------------------------------
pi@raspberrypi:~/daqhats/examples/c/mcc118/single_value_read $ ./single_value_read
MCC 118 single data value read example
Function demonstrated: mcc118_a_in_read
Channels: 0 - 3
Options: OPTS_DEFAULT
Press 'Enter' to continue
Acquiring data ... Press 'Enter' to abort
Samples/Channel Channel 0 Channel 1 Channel 2 Channel 3
283 1.74047 V 1.74062 V 1.74109 V 1.74167 V
刚买了MCC118，配置完毕，不连接任何接线，空载，用示例里的single_value_read读取数据，显示值始终为～1.74V。
如果将CH0等接树莓派IO引脚上的5V、0V，也没有任何变化。
请问这是什么问题？
MCC 118 single data value read example
Function demonstrated: mcc118_a_in_read
Channels: 0 - 3
Options: OPTS_DEFAULT
Press 'Enter' to continue
Acquiring data ... Press 'Enter' to abort
Samples/Channel Channel 0 Channel 1 Channel 2 Channel 3
1132 1.74047 V 1.74062 V 1.74109 V 1.74167 V
