# SerialPort on BalenaOS not working **URL:** \ **Category:** balenaOS\ **Tags:** docker\ **Created:** [June 10, 2022, 12:24am UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741 "2022-06-10T00:24:23Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 10, 2022, 12:24am UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/1 "2022-06-10T00:24:24Z")
Trying to get a USB-[FTDI]-device connected to my `Asus Tinker S R2.0` board on Balena-Cloud (i.e. running balenaOS). The problem is: - if I run my code on the original Tinker image (i.e. Debian I think this is) → then everything works - if I run the exact same code on a balenaOS image (Tinker S) → then the USB-[FTDI]-device cannot be read ! Instead there are a couple of strange letters (E01 E008 etc dropping in at the startup - but no actually expected serial data coming in). The port is recognised but no data comes in. Here is the excerpt of the Docker.template file: > RUN sudo apt-get update -y > RUN sudo apt-get install -y python3 > #the following two lines are needed for node-package SerialPort and usb-detection to work properly > RUN sudo apt-get install -y build-essential > RUN sudo apt-get install -y libudev-dev > ENV UDEV=1 As mentioned already, also with the balenaOS version, the serialport is recognised and the port can be opened. However, no incoming data from the serialport can be read. The port is: `tty.usbmodem6250301` as I find the device inside `/dev` Any idea what I have to do in order for the balenaOS also to work with the USB-device on the SerialPort ?? ---
**Author:** ![anujdeshpande](https://sea2.discourse-cdn.com/balena/user_avatar/forums.balena.io/anujdeshpande/32/3155_2.png) [@anujdeshpande](https://forums.balena.io/u/anujdeshpande)\ **Post date:** [June 10, 2022, 11:51am UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/2 "2022-06-10T11:51:21Z")
Hi Are you hot plugging the device by any chance? ---
**Author:** ![anujdeshpande](https://sea2.discourse-cdn.com/balena/user_avatar/forums.balena.io/anujdeshpande/32/3155_2.png) [@anujdeshpande](https://forums.balena.io/u/anujdeshpande)\ **Post date:** [June 10, 2022, 11:52am UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/3 "2022-06-10T11:52:09Z")
Also, did your debian install have any drivers that you put there for the said ftdi chip? ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 10, 2022, 12:03pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/4 "2022-06-10T12:03:13Z")
no and no. (i.e. no hot plugging and no special drivers installed with debian) ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 10, 2022, 12:05pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/5 "2022-06-10T12:05:28Z")
The working image is: Tinker Board S R2.0 Debian 10 V3.0.11 Board: Tinker Board S R2.0 Link: [Tinker Board](https://tinker-board.asus.com/download-list.html?product=tinker-board-s-r2). (very bottom of page) The balenaOS version that is NOT working: BalenaOS 2.38.3+rev1 (Development) * * * and actually to be clear: Eventually I would like to use hot plugging ! But for now, I can live with having the dongle plugged into one of the Tinker USB-plugs at power-on…) ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 11, 2022, 12:41am UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/6 "2022-06-11T00:41:54Z")
The USB[FTDI] device that is not read correctly with balenaOS turns out to be on `/dev/ttyACM0` Either it is a FTDI-driver issue - but how are they different from balenaOS-image to Tinker-Debian-image ?? Or it is a permission issue of this `/dev/ttyACM0` serialport. Or something completely else… I don’t think it is an issue with the node-packages [serialport](https://npm.io/package/serialport) and [usb-detection](https://npm.io/package/usb-detection) - since they run fine for the Tinker-Debian-image without issue. Only the balenaOS messes-up the USB[FTD] reading. Any idea what I can do ? ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 11, 2022, 11:37am UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/7 "2022-06-11T11:37:33Z")
I also tried (without success unfortunately) adding a docker-compose.yaml file that defines the `/dev/ttyACM0` device explicitely: Still, it does not work - any more ideas ??? ```auto version: "2.1" services: hello: build: . restart: always privileged: true network_mode: host devices: - "/dev/ttyACM0:/dev/ttyACM0" cap_add: - SYS_RAWIO ``` This is what gets spit out after the serialport Port Creation (see below). On Tinker-Debian, none of this nonsense-log is happening. Instead the serialport can read the port correctly. Here is the log on the balenaOS: (it should not happen) : ```auto [Logs] [6/11/2022, 13:35:43] [hello] [SUCCESS]: /dev/ttyACM0: PORT OPENED [Logs] [6/11/2022, 13:35:43] [hello] 0 [Logs] [6/11/2022, 13:35:47] [hello] 0OK [Logs] [6/11/2022, 13:35:47] [hello] [Logs] [6/11/2022, 13:35:47] [hello] 0OK [Logs] [6/11/2022, 13:35:47] [hello] OK [Logs] [6/11/2022, 13:35:47] [hello] [Logs] [6/11/2022, 13:35:47] [hello] 0OK [Logs] [6/11/2022, 13:35:47] [hello] OK [Logs] [6/11/2022, 13:35:47] [hello] E [Logs] [6/11/2022, 13:35:48] [hello] 0OK [Logs] [6/11/2022, 13:35:48] [hello] OK [Logs] [6/11/2022, 13:35:48] [hello] E1 [Logs] [6/11/2022, 13:35:48] [hello] 0OK [Logs] [6/11/2022, 13:35:48] [hello] OK [Logs] [6/11/2022, 13:35:48] [hello] E1 [Logs] [6/11/2022, 13:35:48] [hello] 0OK [Logs] [6/11/2022, 13:35:48] [hello] OK [Logs] [6/11/2022, 13:35:48] [hello] E1 E [Logs] [6/11/2022, 13:35:48] [hello] 0OK [Logs] [6/11/2022, 13:35:48] [hello] OK [Logs] [6/11/2022, 13:35:48] [hello] E1 E0 [Logs] [6/11/2022, 13:35:51] [hello] 0OK [Logs] [6/11/2022, 13:35:51] [hello] OK [Logs] [6/11/2022, 13:35:51] [hello] E1 E0OK [Logs] [6/11/2022, 13:35:51] [hello] [Logs] [6/11/2022, 13:35:51] [hello] 0OK [Logs] [6/11/2022, 13:35:51] [hello] OK [Logs] [6/11/2022, 13:35:51] [hello] E1 E0OK [Logs] [6/11/2022, 13:35:51] [hello] OK [Logs] [6/11/2022, 13:35:51] [hello] 0OK [Logs] [6/11/2022, 13:35:51] [hello] [Logs] [6/11/2022, 13:35:51] [hello] OK [Logs] [6/11/2022, 13:35:51] [hello] E1 E0OK [Logs] [6/11/2022, 13:35:51] [hello] OK [Logs] [6/11/2022, 13:35:51] [hello] E [Logs] [6/11/2022, 13:35:52] [hello] 0OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] E1 E0OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] E1 [Logs] [6/11/2022, 13:35:52] [hello] 0OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] E1 E0OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] E1 [Logs] [6/11/2022, 13:35:52] [hello] 0OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] E1 E0OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] E1 E [Logs] [6/11/2022, 13:35:52] [hello] 0OK [Logs] [6/11/2022, 13:35:52] [hello] E1 E0OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] OK [Logs] [6/11/2022, 13:35:52] [hello] E1 E0 ``` ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 11, 2022, 3:07pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/8 "2022-06-11T15:07:08Z")
I also tried to change the udevRules in the `config.json`. Unfortunately, still without success ☹ I am more than desperate to get this USB[FTDI] reading issue up-n-running ! Does anyone have more ideas ??? Here is the udev-rules that I added to the config.json: ```auto "os": { "udevRules": { "56": "ENV{ID_FS_LABEL_ENC}==\"resin-root*\", IMPORT{program}=\"resin_update_state_probe $devnode\", SYMLINK+=\"disk/by-state/$env{BALENA_UPDATE_STATE}\"", "64": "ACTION!=\"add|change\", GOTO=\"modeswitch_rules_end\"\nKERNEL==\"ttyACM*\", ATTRS{idVendor}==\"abcd\", ATTRS{idProduct}==\"1234\", TAG+=\"systemd\", ENV{SYSTEMD_WANTS}=\"u-blox-switch@'%E{DEVNAME}'.service\"\nLBEL=\"modeswitch_rules_end\"\n" } } ``` ---
**Author:** ![nmaas87](https://sea2.discourse-cdn.com/balena/user_avatar/forums.balena.io/nmaas87/32/5570_2.png) [@nmaas87](https://forums.balena.io/u/nmaas87)\ **Post date:** [June 11, 2022, 5:39pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/9 "2022-06-11T17:39:46Z")
I would use dmesg, lsmod (in balenaOS, not in a container, I would try to get it working first before going further…) and see if the FTDI really mounts as ttyACM0 and not something else. Then I would use stty to set the USB FTDI to some correct speed and maybe try to bridge the serial side of the FTDI chip and play around with echo and try to send some data and see if this works. It would also be useful to know which USB FTDI you are using, possible that there are driver issues within Yocto for that specific FTDI chip (you can acquire the vendor and hw ids via lsusb on any linux machine). Best of luck ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 11, 2022, 8:36pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/10 "2022-06-11T20:36:42Z")
Thank you nmaas87, 90% of what you suggest I have done. Since I can plug/unplug the USB[FTDI] to my Tinker-Debian with no issues, I am absolutely sure that it works. Also if I connect it to an App called [`Serial`](https://www.decisivetactics.com/products/serial/), it all works too ! And if I plug it to my Tinker-balenaOS then the [serialport](https://npm.io/package/serialport) and [usb-detection](https://npm.io/package/usb-detection) Node-packages do bring me the information that the USB[FTDI] connected to `/dev/ttyACM0` just the same way it does when plugged to Tinker-Debian. `[Logs] [6/11/2022, 13:35:43] [hello] [SUCCESS]: /dev/ttyACM0: PORT OPENED` Now since I work with a serialport parser, I get all the information logged that comes from the USB[FTDI]. The log shows anything coming from the USB-port that is read to the serialport-buffer. For a test-device with a simple RS232-to-USB[FTDI] converter, I have everything working nicely (i.e. I can write anything to the serialport-buffer). And even the Tinker-balenaOS then works !! But for the USB[FTDI] dongle at question, there are these messy `E0` and `E` and `OK` numbers that are pushed. I think you are right with the assumption that the FTDI-chip (or timing settings) are not compatible with Yocto. The question is: What is different in Tinker-balenaOS compared to Tinker-Debian ??? ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 13, 2022, 12:26pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/11 "2022-06-13T12:26:10Z")
The solution was to change the board (and together with it, to change the balenaOS-version) Before: `balenaOS 2.38.3 (rev 1)` for `Tinker Asus S` → the USB[FTDI] dongle at question is not working After: `balenaOS 2.98.33` for `Generic_x86_64` → everything working fine - the USB[FTDI] dongle at question is working just great !!! It is not clear to me whether it was the different driver or wether the Yocto-kernel also shows differences within these two balenaOS-versions. Anyway, I will not use the Tinker S with balenaOS 2.38.3 anymore for this USB dongle but rather the new combination of HW and OS. ---
**Author:** ![nmaas87](https://sea2.discourse-cdn.com/balena/user_avatar/forums.balena.io/nmaas87/32/5570_2.png) [@nmaas87](https://forums.balena.io/u/nmaas87)\ **Post date:** [June 13, 2022, 3:05pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/12 "2022-06-13T15:05:07Z")
The newer balenaOS will probably use a newer Yocto version, so that will change a lot. Having another architecture also helps, but I think there might have been some problems with the older Yocto. Nice that you got it working, all the best! ---
**Author:** ![skuenstler](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@skuenstler](https://forums.balena.io/u/skuenstler)\ **Post date:** [June 13, 2022, 5:36pm UTC](https://forums.balena.io/t/serialport-on-balenaos-not-working/358741/13 "2022-06-13T17:36:27Z")
Thank you for confirming Yocto-versions. The balena-officially recommended version for the `Asus Tinker S` board is `balenaOS 2.38.3 (rev 1)` . I never tried to install a newer version since recommended. As you said, the best bet is probably to go with the new Yocto-version preferably and choose a HW-board that fulfils the recommended balenaOS-version. Thank you for your thoughts and contributions.