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skydiverman
USA
15 Posts |
 Posted - 09/29/2023 : 18:43:25
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Hi all - I have a GMC 500+ and have been successfully reading/writing to the COM port on my windows x86 laptop for some time. I built a project computer using a raspberry Pi 4 specifically to run my application which reads the data but now find that the CH340 driver supplied does not seem to work. the PI is running windows 10. Questions - 1: is the CH 341 driver intended to work on the ARM64 processor of pi 4b? if not, is there any other alternative ? the windows driver appears to try to work, but I simply cannot get communication back and forth over the wire.
alternatively if I had to use the wifi, do i interpret correctly that CPM and ACPM are tubes 1 and 2 as given in the manual; "Example:
h**p://www.GMCmap.com/log2.asp?AID=0230111&GID=0034021&CPM=15&ACPM=13.2&uSV
=0.075"
it seems odd that ACPM would be 13.2 so that sounds more like average CPM, but if so how would tubes 1 and 2 both be submitted ?
thanks |
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| Reply #1
skydiverman
USA
15 Posts |
Posted - 09/29/2023 : 18:46:40
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| To be clear, the alternative thought process would be to stand up a web service to receive the payloads directly from the meter rather than allowing them to actually transit to the GMCMAP, as the intended use would be not connected to the internet. the primary connection through the USB micro connection is preferred, however. |
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| Reply #2
ullix
Germany
1171 Posts |
Posted - 09/29/2023 : 22:52:33
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I run any GMC counter on the Raspi, but under Linux. It works easily. Code can be found as part of my GeigerLog package https://sourceforge.net/projects/geigerlog/
But I never tried Windows on a Raspi; I am surprised it even works.
For the GMCMAP the CPM is the last measured value for CPM, and ACPM the average of this CPM since last boot. Such a definition for ACPM does not make sense, since for a counter running for a long time it will barely change even in a major catastrophe!
For a GMC-500 an additional problem arises, as the CPM is taken as the sum of counts on the first plus the second tube. This is utter nonsense. You can only overcome this by switching the second tube off.
You could do it properly by using GeigerLog to do the map upgrades. It runs well on Raspis. You could even run it on Windows on Raspi, provided you had solved the CH340 driver issue. |
Edited by - ullix on 09/29/2023 22:53:35 |
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| Reply #3
skydiverman
USA
15 Posts |
Posted - 09/30/2023 : 05:21:05
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Interesting. I thought i saw some driver support on linux, but My app is .net 6, so windows as i tried wine and that was a no-go. Windows 10 IOT was abandoned, but windows continues to have the needed support for ARM64, including windows 11. but there are limits, like the wifi doesnt work, and the drivers available seem limited. thus my position now where I could either take the CPM via network using a service and a dedicated wifi router or maybe simpler fallback position might be to run your code on linux. as you note, it would be simpler to support, and the core issue is the ch341 driver. I had ubuntu running and also raspian and both ran well on the pi.
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Edited by - skydiverman on 09/30/2023 05:23:08 |
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| Reply #4
ullix
Germany
1171 Posts |
Posted - 10/01/2023 : 23:28:36
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| On any Linux the CH340 driver is installed by default. |
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| Reply #5
skydiverman
USA
15 Posts |
Posted - 10/07/2023 : 10:27:44
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quote:
Originally posted by ullix
On any Linux the CH340 driver is installed by default.
running ubuntu 22 now and have geigerlog up and running but i consistently get "Failure connecting with device; ... A GMC Device was not detected".
unclear to me how to verify that the ch341 is installed but I know the device see's connection via the serial input indication, and the cable is the same one I used on the windows pc that does work correctly. any thoughts on how to diagnose? |
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| Reply #6
skydiverman
USA
15 Posts |
Posted - 10/07/2023 : 17:20:57
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| hmm.. see h**ps://askubuntu.com/questions/1403705/dev-ttyusb0-not-present-in-ubuntu-22-04 sudo apt remove brltty resolved part of the issue. but still I see ttyUSB0, but geigerlog doesnt. configuration seems right too. h**ps://i.imgur.com/NBTldZ2.jpg is a screen shot of the device showing ports and dmesg. |
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| Reply #7
ullix
Germany
1171 Posts |
Posted - 10/09/2023 : 00:50:17
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Strange. According to your dmesg screenshot, after removing the braille stuff all should be set; the CH34X chip is recognized and mapped to /dev/ttyUSB0. Not sure about the relevance of the MMU error message.
What puzzles me a bit is that your dmesg shows CH341 while the IDs do belong to a CH340. Please, verify and post the printout of 'lsusb'. You should see a line like: 'ID 1a86:7523 QinHeng Electronics CH340 serial converter'.
Which version of GeigerLog are you using - Ubuntu has the unfortunate property of removing this info :-( ?
To be sure: you did not make any changes to the configuration file geigerlog.cfg beyond setting 'GMC_Activation = yes' ?
If this problem needs more actions I suggest to download the latest GeigerLog development version, which you find here: https://sourceforge.net/p/geigerlog/discussion/devel/
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| Reply #8
skydiverman
USA
15 Posts |
Posted - 10/10/2023 : 18:19:59
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i went back to running the code directly from the terminal prompt, and this paid off. same error occurs, but in the terminal window the exception data is logged.
... Errno:13 could not open port /dev/ttyUSB0: [Errno 13] permission denied: '/dev/ttyUSB0' in file : gdev_gmc.py ... |
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| Reply #9
ullix
Germany
1171 Posts |
Posted - 10/10/2023 : 23:48:27
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Oh, the permissions issue in Linux, of course.
In the GeigerLog manual follow chapter "Appendix B – Connecting Device and Computer using a Serial Connection".
With the latest GeigerLog versions take advantage of the auto-discovery of GeigerLog and follow with Option: 2) Make yourself a member of group 'dialout'. GeigerLog does the rest.
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Topic |
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USB Driver CH341 on Raspberry Pi
