Using Linux to Upload Code

[daveclifford]

Using Linux to Upload Code

Contributed by Dave Clifford - 2023-03-28

Linux can be used in creating a EX-T3-WiFi throttle to build/upload the file system image as well as build/upload the FireBeetle 2 control program.

This guide defines a process and steps to install/check installation of the tools needed to to communicate from the Linux system to the Fire Beetle 2 and check user permissions to use the tools.

Hardware to Be Used

The FireBeetle 2 ESP32-E IoT Microcontroller with Header (FireBeetle 2) (DFRobot SKU:DFR0654-F) communicates to an external wired device via a USB C to USB C (or USB A) interface cable.

NOTE: USB C cables can have variations in speed, power, and protocol capabilities. A USB C cable with 3.1 Gen 2 capabilities vs one with 2.0 can mean a vast difference in data transfer.

The FireBeetle 2 ESP32-E USB to UART interface chip used to do this communication is the CH340K (vendor is identified as QinHeng Electronics).

Checking If The USB Driver is Installed

The Linux operating system communicates with internal and external devices via an extensive set of drivers provided by the kernel.

The current Linux driver providing the signal and control for the CH340K USB Bridge Controller is the CH341 driver.

The Linux Kernel V5 Series has ch341.ko driver support.

A search in a new (2023-03-25) Linux system kernel shows the CH341 USB serial driver is installed in

 $ find /lib/* -type f -name "*ch341.ko"

/lib/modules/5.19.0-38-generic/kernel/drivers/usb/serial/ch341.ko

If the developer plugs in the FireBeetle 2 to a USB port and then uses the terminal window command,

 $ lsusb -t 

he should see an output stream showing that the ch341 driver is attached to a USB port, similar to

==> Port 2: Dev 7, If 0, Class=Vendor Specific Class, Driver=ch341, 12M

This establishes that the driver is defined in the kernel and loaded for use.

This does NOT establish that the user has permission to use the driver.

Setting User Permissions to Use The CH341 USB Driver

There are two steps to take to set permissions for the user to use the USB port to transfer the code to the FireBeetle 2.

The first step is to enable TTY Ports for use.

Linux has an extensive security system to lock every port and requires the user to add controls to open ports for use.

Linux users need to install Udev Rules for PlatformIO supported boards/devices.

The latest version of the rules may be found at [99-platformio-udev.rules] (https://raw.githubusercontent.com/platformio/platformio-core/develop/platformio/assets/system/99-platformio-udev.rules).
The instructions are thorough and use a curl command string for installing to your Linux system.

The second step is to add the user to the dialout Group.

The dialout group membership provides full and direct access to serial ports. Members of this group can reconfigure the modem, dial anywhere, etc.

   sudo adduser $USER dialout

The adduser command will add you [$USER] to the dialout group which controls access to the serial ports.

The port my system uses is /dev/ttyUSB0 and is defined within the dialout group.

Install Visual Studio Code for Linux

Visual Studio Code for Linux should be able to be installed using the package installer that come with your distribution.
.
The package name is code and the version that was installed is version 1.76.2-1678817801.

Install the PlatformIO IDE Extension within Visual Studio Code for Linux

Startup the Code application. Search for Extensions and add the PlatformIO IDE.

My installed version is v3.1.1.

NOTE: The startup time is 223 seconds.

Modify Your Linux Shell File to Define the USB Port To Be Used To Upload the Builds

Your shell file resides in your home directory and defines the tools, formats, parameters, etc. to be used while the session is active of your shell.

My Linux distribution use the bash shell, so my shell file is named .bashrc.

In order to communicate with the FireBeetle 2 through the PlatformIO upload port, I had to add a port definition to the .bashrc file.
This will define the port at the user session level, not at the application level.

   export PLATFORMIO_UPLOAD_PORT=/dev/ttyUSB0

[Don't add a port definition to the platformio.ini within the EX-T3-WiFi .git tree! I discovered that GIT saw my discrepancy and wanted me to promote the change!]

The user is achieving the same solution (by using the user session resource file) - defining the upload port to be used for PlatformIO - but is not affecting the integrity of the git package.

I hope this road map helps you to successfully build/upload your EX-T3-WiFi throttle software!

[daveclifford]

Alex,

Please consider promoting this to your .doc tree so others can easily find the Linux instructions.

The references you provided for markup were very helpful!!

Please fell free to make any syntax changes; please consult me for the Linux commands.

Thanks,

Dave.

[daveclifford]

I tried and have one to go, but I wanted to update it before and discovered that I couldn't.
I will send you a pull request and maybe it then can let me do the update.

Dave

[daveclifford]

I think I sent you a pull request - Let me know what you think and if it worked. It is my first time to pull a request

Consider yourself my mentor

Dave

[daveclifford]

Alex,

Here's a screen capture of the pull request. I have a fork of the EX-T3-Wiki. I added the doc to the fork and requested a pul to your reepository. I am new at this, so I may have thought I requested a pull, but Git is confused (or I am, more so).

Dave

[alex-code]

Hi Dave,

I think you've done a PR to your fork.
When doing the compare you need to select the DCC-EX/EX-T3-WiFi repo on the base drop-down.
That should then create a PR here I can merge in.

[daveclifford]

I think i fixed the PR. It was in my fork to my fork - not across my fork and your master.

You should rename the file xxx.md I forgot to add the .md suffix.

Also you may wish to change the file name to just Using Linux.md

An aside - how can I get a spell checker enabled for use in writing these words?

Dave