Rpi 3B+ with 0c45:7401 TEMPerF1.4

[nigels-com]

Made both of these changes and updated the timeout from 0.2 to 0.5 and still get failures every other read when running
while true; do sudo ./temper2.py; sleep 5; done
on an RPi 3 B+

Just investigating, the regularity of it made me call hardware into question, checking dmesg it shows brownout on each successful read, subsequently returning rubbish. Will confirm with new PSU.

__ Update:
PSU swapped for a high current one, no improvement - power drop out doesn't happen but still get errors.

Output modified as I don't need all the bumf, but....
--@--:/home/pi# ./temper2.py
21.5 2020-01-21 21:01:39
--@--:/home/pi# ./temper2.py
21.5 2020-01-21 21:01:41
--@--:/home/pi# ./temper2.py
Traceback (most recent call last):
File "./temper2.py", line 434, in
sys.exit(temper.main())
File "./temper2.py", line 427, in main
results = self.read(args.verbose)
File "./temper2.py", line 345, in read
results.append({ **info, **usbread.read() })
File "./temper2.py", line 272, in read
return self._read_hidraw(self.device)
File "./temper2.py", line 180, in _read_hidraw
firmware = self._read_hidraw_firmware(fd, self.verbose)
File "./temper2.py", line 159, in _read_hidraw_firmware
raise RuntimeError('Cannot read device firmware identifier')
RuntimeError: Cannot read device firmware identifier

Originally posted by @bucklevision in #16 (comment)

[nigels-com]

Further information via that discussion:

It seems to happen with successive calls within 2ish seconds. Give it 5 and most of the time it's OK.

lsusb:
Bus 001 Device 005: ID 0c45:7401 Microdia TEMPer Temperature Sensor
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

output of /sys/kernel/debug/usb/devices
T: Bus=01 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#= 5 Spd=1.5 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
P: Vendor=0c45 ProdID=7401 Rev= 0.01
S: Manufacturer=RDing
S: Product=TEMPerV1.4
C:* #Ifs= 2 Cfg#= 1 Atr=a0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=01 Driver=usbhid
E: Ad=81(I) Atr=03(Int.) MxPS= 8 Ivl=10ms
I:* If#= 1 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=usbhid
E: Ad=82(I) Atr=03(Int.) MxPS= 8 Ivl=10ms

It's one of these:
https://pcsensor.com/usb-thermometers/gold-temper.html

However it was purchased from Amazon.

[nigels-com]

Indeed, I can reproduce this setup and issue here too:

$ lsusb
Bus 001 Device 103: ID 0c45:7401 Microdia TEMPer Temperature Sensor
Bus 001 Device 004: ID 0bda:8179 Realtek Semiconductor Corp. RTL8188EUS 802.11n Wireless Network Adapter
Bus 001 Device 005: ID 0424:7800 Standard Microsystems Corp. 
Bus 001 Device 003: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub
Bus 001 Device 002: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

T:  Bus=01 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#=103 Spd=1.5  MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=0c45 ProdID=7401 Rev= 0.01
S:  Manufacturer=RDing
S:  Product=TEMPerV1.4
C:* #Ifs= 2 Cfg#= 1 Atr=a0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=01 Prot=01 Driver=usbhid
E:  Ad=81(I) Atr=03(Int.) MxPS=   8 Ivl=10ms
I:* If#= 1 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=01 Prot=02 Driver=usbhid
E:  Ad=82(I) Atr=03(Int.) MxPS=   8 Ivl=10ms

[nigels-com]

Works:

$ while true; do sudo ./temper.py; sleep 10; done
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.50C 92.30F - - - -

Does not:

$ while true; do sudo ./temper.py; sleep 1; done
Traceback (most recent call last):
  File "./temper.py", line 432, in <module>
    sys.exit(temper.main())
  File "./temper.py", line 425, in main
    results = self.read(args.verbose)
  File "./temper.py", line 342, in read
    results.append({ **info, **usbread.read() })
  File "./temper.py", line 269, in read
    return self._read_hidraw(self.device)
  File "./temper.py", line 177, in _read_hidraw
    firmware = self._read_hidraw_firmware(fd, self.verbose)
  File "./temper.py", line 157, in _read_hidraw_firmware
    raise RuntimeError('Cannot read device firmware identifier')
RuntimeError: Cannot read device firmware identifier
Bus 001 Dev 103 0c45:7401 TEMPerF1.4 33.81C 92.86F - - - -
Traceback (most recent call last):
  File "./temper.py", line 432, in <module>
    sys.exit(temper.main())
  File "./temper.py", line 425, in main
    results = self.read(args.verbose)
  File "./temper.py", line 342, in read
    results.append({ **info, **usbread.read() })
  File "./temper.py", line 269, in read
    return self._read_hidraw(self.device)
  File "./temper.py", line 177, in _read_hidraw
    firmware = self._read_hidraw_firmware(fd, self.verbose)
  File "./temper.py", line 157, in _read_hidraw_firmware
    raise RuntimeError('Cannot read device firmware identifier')
RuntimeError: Cannot read device firmware identifier

[nigels-com]

Changing the timeout from 0.2 to 0.6 seems to work for this setup.
It does seem like an excessively long time to use by default, though.
https://github.com/nigels-com/temper/tree/timeout-rpi3b

[nigels-com]

I also hava a Raspberry Pi Zero W, which exhibits a similar problem for the same TEMPerF1.4:

Feb 19 22:13:19 raspberrypi td-agent-bit[1079]: Traceback (most recent call last):
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:   File "/usr/local/bin/temper.py", line 432, in <module>
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:     sys.exit(temper.main())
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:   File "/usr/local/bin/temper.py", line 425, in main
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:     results = self.read(args.verbose)
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:   File "/usr/local/bin/temper.py", line 342, in read
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:     results.append({ **info, **usbread.read() })
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:   File "/usr/local/bin/temper.py", line 269, in read
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:     return self._read_hidraw(self.device)
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:   File "/usr/local/bin/temper.py", line 177, in _read_hidraw
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:     firmware = self._read_hidraw_firmware(fd, self.verbose)
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:   File "/usr/local/bin/temper.py", line 157, in _read_hidraw_firmware
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]:     raise RuntimeError('Cannot read device firmware identifier')
Feb 19 22:13:19 raspberrypi td-agent-bit[1079]: RuntimeError: Cannot read device firmware identifier
...
Feb 19 22:15:03 raspberrypi td-agent-bit[1079]: [0] temper: [1582114500.107316296, {"internal temperature"=>25.625000}]
...
$ make logs | grep temper:
Feb 19 22:17:16 raspberrypi td-agent-bit[1422]: [0] temper: [1582114632.933642098, {"internal temperature"=>26.562500}]
Feb 19 22:17:21 raspberrypi td-agent-bit[1422]: [0] temper: [1582114637.978755096, {"internal temperature"=>26.750000}]
Feb 19 22:17:26 raspberrypi td-agent-bit[1422]: [0] temper: [1582114642.938570485, {"internal temperature"=>26.625000}]
Feb 19 22:17:31 raspberrypi td-agent-bit[1422]: [0] temper: [1582114647.963719339, {"internal temperature"=>26.500000}]
Feb 19 22:17:36 raspberrypi td-agent-bit[1422]: [0] temper: [1582114652.947055894, {"internal temperature"=>26.625000}]
Feb 19 22:17:41 raspberrypi td-agent-bit[1422]: [0] temper: [1582114657.954845623, {"internal temperature"=>26.500000}]