 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Microcontroller and PC projects : LINUX: Getting Mint to see a USB com port...
| Author | Message | ||||
Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
I'm trying to get a Prolific USB-serial adaptor working in Mint 20, but Mint basically refuses to see it or talk to it, BUT Mint knows it is there. I have a feeling, I have to add the device to the dialout group, but I forget how you do that, as I don't use Linux commandline on a daily basis.  Can one of the Linux gurus here please help?  I am trying to use the adaptor with PuTTY, but PuTTY refuses to even SEE the adaptor, so the problem is two-fold: 1) I need to make Mint allow PuTTY to "SEE" the adaptor at a standard Linux serial-port path such as /dev/ttyACM0 2) I then need to add myself to the dialout group, as I think that is disabled by default, and you have to have that enabled to allow use of serial ports in Linux. Thanks for any help. I did look at Mr. Google, and there are a plethora of results, and it is all so confusing as different websites use different methods and I get totally lost.  Smoke makes things work. When the smoke gets out, it stops! |
||||
TassyJim Guru  Joined: 07/08/2011 Location: AustraliaPosts: 6100 |
You have to be a member of the dialout group. You have to logout and back in for it to take effect. You might have to get rid of modemmanager sudo apt-get purge modemmanager The commands to get rid of it may vary. Search the forum. What is the output of dmesg A lot of Prolific devices are clones and Prolific got sneaky in order to stop the clones working on Windows. I don't thik that is the case for LInux. Jim VK7JH MMedit MMBasic Help |
||||
| toml_12953 Guru Joined: 13/02/2015 Location: United StatesPosts: 339 |
Most USB adaptors are listed in /dev as ttyUSBx where x is a number from 0 to the total number of USB serial adapters - 1. That's how my Prolific USB to serial adapter is listed. |
||||
Quazee137 Guru Joined: 07/08/2016 Location: United StatesPosts: 571 |
my checkcomms.sh #!/bin/bash echo "Comms are" echo "------- USB's ---------" ls -l /dev/ttyUSB* echo echo "------- ACM's ---------" ls -l /dev/ttyACM* echo echo "plug in device press key" read $key echo echo "Any thing new " echo echo "------- USB's ---------" ls -l /dev/ttyUSB* echo echo "------- ACM's ---------" ls -l /dev/ttyACM* echo read $key exit crude but has worked for years.  came out of lsusb ls /dev/tty* ls /dev/ttyACM* ls /dev/ttyUSB* hope it helps thinking of MMB4L as a shell for things like this just haven't had time to play. Quazee137 |
||||
| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2350 |
usermod -a -G dialout $USER you may need a sudo in front of that too. does GFXterm see it? cheers, rob :-) |
||||
andreas Senior Member  Joined: 07/12/2020 Location: GermanyPosts: 207 |
to see the groups you are in: groups to add an existing user to an existing group:adduser <user> <group> ls /dev/ plugin device ls /dev/ ..and compare what changed ;-) or dmesg just after plugging in the device -andreas |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Lots of replies! Thanks!  My Prolific unit IS a genuine article. Cost about $30 from Jaycar. I am NOT trying to use one of the often problematic eBay clone ones(often in translucent iMac blue colour).  @ Rob - can you link me to the Linux version of GFXterm? I only have the Windows ones, and I can't remember where I got those from now! dmesg result is HUGE, so I can't take a photo of it. Is there a command to make it save the result as a text file somewhere I can copy it from? It may not be needed anyway - see below... @ Quazee137: This is the output I get from those commands...  From what I can tell from this, I am already a member of the dialout group, and I think the Prolific adaptor is at /dev/ttyUSB0. Inside PuTTY, I cannot select /dev/ttyUSB0. All it will let me select is /dev/ttyS0. I cannot backspace and even TRY to type in the USB0 location - backspace has no effect. EDIT: Hold the phone - In PuTTY, right down the bottom of the config window, under Category, I can enter in the /dev/ttyUSB0 reference there, and it seems to open OK. Now I just need to connect something up to be sure it is working.... Edited 2023-06-12 16:08 by Grogster Smoke makes things work. When the smoke gets out, it stops! |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
COM port is now working in PuTTY. Would prefer to use GFXterm though, so Rob - as soon as you see this.... Smoke makes things work. When the smoke gets out, it stops! |
||||
atmega8 Guru Joined: 19/11/2013 Location: GermanyPosts: 722 |
A piece of wire between pin 2/3 gives a nice echo🤓 Edited 2023-06-12 16:37 by atmega8 |
||||
| atmega8 Guru Joined: 19/11/2013 Location: GermanyPosts: 722 |
Modemmanager, NOT modemanager! |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Yes, I should have thought of the loopback test! However, I had a thing on the bench ready to connect to it, which I knew worked on the same Prolific adaptor and a Windoze laptop, so.... F-ing Linux! Totally missed that extra "m" - very well hidden..... In any event, it did not seem to matter, as the COM port is working now. Smoke makes things work. When the smoke gets out, it stops! |
||||
thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4043 |
dmesg > out.txt Use > to redirect the standard output from any console command to a file. Best wishes, Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2350 |
try the following: dmesg -w this waits after printing all the messages, adding new messages as they arrive - press ctrl-C to exit. so with dmesg waiting, hit the enter key a few times (to create some blank lines) and then plug in your USB device to see the new messages associated with it displayed. hit the enter key a few more times (for more blank lines) then unplug the USB device to see 'unplug' events. ModemManager is a right pain. when active, if it sees a serial device plugged in that it thinks may be a modem, it proceeds to try talking to it. if the device is a modem, this is all fine and dandy. if it is not a modem things can quickly go to custard as the device gets thoroughly confused by the gobbledygook being sent to it. TassyJim's advice to simply get rid of it is sound. GFXterm's new home is here: https://github.com/robert-rozee/GFXterm the binaries folder contains pre-compiled binaries for 32- and 64-bit linux, as well as win32. in theory, it should also be possible to compile for RPi. new changes are: 1. anything being pasted that is only one line long now does NOT have a carriage return appended (as requested by Frank N. Furter), and, 2. there is now a new menu option, "screen size" that enables you to manually set the screen size to anything between 40x16 and 160x60. this should accommodate the needs of the pico versions of MMbasic. cheers, rob :-) |
||||
| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3150 |
Re dmesg, if you start up your device and then plug in the USB/serial module "dmesg | tail" will usually give you what you want, e.g., ttyUSB0 (or the like). PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
||||
| Andy-g0poy Regular Member  Joined: 07/03/2023 Location: United KingdomPosts: 59 |
Permissions are assigned to users as are groups Use whatever user manager you normally use. This will need to be run as root. Permission changes sometimes need you to log out and log back in again The backspace issue: putty defaults to using (I think) 127 as backspace. Backspace is control+H try that and see it it works. If so there is a putty setting that sets the backspace behaviour, choose the send control H option You can't usually access a dev with an ls. devs are files. Use ls -l (long listing to get a bit more info, and remember to pass the output through grep is things get too long ls -l /dev | grep ttyU will pull out all the ttyUSB devices. grep is also useful for taming dmesg Andy |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Lovely, thanks for the pointers, chums.  I have now removed modemmanager using the extra m this time. It completed without errors, so that should now be gone. EDIT: @ Rob - Can download the file, but Mint does not know what to do with it. Mint moans that the file has no application associated with it. The file has NO extension, and the W10 machine I downloaded it on, just refers to it as filetype "File". Do I need to rename and add an extension perhaps? Edited 2023-06-13 10:26 by Grogster Smoke makes things work. When the smoke gets out, it stops! |
||||
| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2350 |
right-click on the file's icon and select 'Properties' from the menu. this will bring up a window with three tabs, the right-most is the one you want, 'Permissions'. here you will find a checkbox with the text "Allow this file to run as a program". check this checkbox, this will then allow the file to be run. with linux, extensions don't have any special meaning in the same way as they do with windows, so no need to rename anything. cheers, rob :-) Edited 2023-06-13 12:23 by robert.rozee |
||||
| Quazee137 Guru Joined: 07/08/2016 Location: United StatesPosts: 571 |
bring up nemo or other file mgr you use right click on  click box  from here on in it should just run. Quazee137 |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Excellent, thanks chums! All up and running. Smoke makes things work. When the smoke gets out, it stops! |
||||
 Print this page |
