Meshtastic Microcontroller Raspberry Pi Software Development

Meshtastic with Raspberry Pi (Serial) – Part I

In this post, I will step through getting Linux installed on a Raspberry Pi with an overview of different installations, and detailed setup on a headless installation. I will then move into connecting the Raspberry Pi to a LilyGo T-Beam device with Meshtastic Firmware, with the connection to the Raspberry Pi using a Serial Connection. Connecting one or more sensors to the Raspberry Pi, and finally sending that data to another Raspberry Pi connected to a LilyGo T-Beam.

Before Installing Linux on Raspberry Pi

There are several options for installing Linux on the Raspberry Pi. The first question to answer is, which distribution to use? There are several different distributions available for the Raspberry Pi boards. A comprehensive list of distributions available may be found at The distribution that I will be using is Raspberry Pi OS by Raspberry Pi.

The next question to answer is do we want a desktop or do we wish to run in headless mode? Installing a desktop is helpful if we wish to use the Raspberry Pi as a regular computer with a nice user interface. Installing a desktop does require more resources but makes the Raspberry Pi more useful if we wish to connect it to a display and keyboard or use VNC from another machine.

A headless mode installation is best if we only need to work from the terminal (command line) and/or we want more resources for running applications to monitor sensors or server up web pages or application program interfaces (API).

The last question to ask is what peripherals and options do we need to have configured? We know we will want the serial interface enabled, since that will be used to communicate to the LilyGo T-Beam devices. Depending on the sensors that we wish to use, we may want to enable the I2C interface.

Another option we will want is to be able to control the Raspberry Pi from another machine as we do not want to connect a monitor, keyboard, and mouse. We will need to enable SSH and VNC to allow control from another machine.

Below is a list of our installation options that we will configure.

  • Distribution: Raspberry Pi OS
  • Mode: Desktop
  • Enable SSH
  • Enable VNC
  • Enable Serial
  • Enable I2C

We have a couple of ways to enable the above configuration but we will configure all of these options from the Raspberry Pi Imager as it makes this relatively easy and quick. The toughest part is determining what the IP Address is of the Raspberry Pi when it boots up.

Required software on the Windows, Linux, or Apple PC

There is some software that we need to have on the PC in order to install the Raspberry Pi OS and control it from the PC.
If the listed software does not support your operating system, look for a similar application for your operating system.

Prepare SD Card for Raspberry Pi

  1. Insert an SD Card in your PC and note the drive letter. Make certain that the SD Card does not have anything that you wish to keep as the card will be wiped, so your information will be gone.
Windows Explorer showing drives with SD Card highlighted
  1. Open the Raspberry Pi OS Imager and click the “Choose OS” button
    In Windows, you will be prompted by the User Account Control (UAC) to continue. Select “Yes”
Raspberry Pi OS Imager window with Choose OS highlighted
  1. Select “Raspberry Pi OS (32-bit)
Raspberry Pi OS Imager - Operating System Listing
  1. Click the button in the lower right corner, with the gear icon for the advanced settings
Raspberry Pi OS Imager with Advanced Options button highlighted
  1. Set the hostname (optional but recommended)
  2. Make certain that “Enable SSH” is checked and “Use password authentication” is selected
  3. Change the password and optionally change the username
  4. Enter the settings for your WiFi connection if not using ethernet
  5. Optionally set time zone and keyboard layout
  6. Once the options have been set, click the “Save” button
Raspberry Pi OS Imager Advanced Options
  1. Click the “Choose Storage” button
Raspberry Pi OS Imager window with Choose Storage highlighted
  1. Select the SD Card identified earlier. Make certain that this is the SD Card as all data will be wiped from the selected drive and will not be able to be recovered.
Raspberry Pi OS Imager showing the list of storage devices that may be used
  1. Click the “Write” button to write the OS image to the SD Card
Raspberry Pi OS Imager window with the "Write" button highlighted
  1. If you are absolutely certain that the correct SD Card has been selected and there is no data on the card that you wish to keep, click the “Yes” button.
Raspberry Pi OS Imager window with the "Yes" button highlighted on confirmation dialog
  1. Once the image has been written to the SD Card, you may click the “Continue” button, close the Raspberry Pi OS Imager, and remove the SD Card from the PC, and insert it into the Raspberry Pi.
Raspberry Pi OS Imager  showing the "Write Successful" dialog
  1. Once the SD Card is inserted into the Raspberry Pi, connect power to the Raspberry Pi
  2. After a couple of minutes, open PuTTY on your PC and attempt to connect to the Raspberry Pi using the name provided in the advanced options of the Raspberry Pi OS Imager. In the example, “pi-sensor01.local” was used. In PuTTY, attempt to connect using the hostname provided in the image configuration.
    NOTE: If configuring another Raspberry Pi, do not use the same hostname.
PuTTY Configuration window showing the options for connecing to SSH Session
  1. Click the “Open” button after entering the hostname
  2. You may see a PuTTY Security Alert if it is the first time connecting to the Raspberry Pi. If so, click the “Accept” button.
PuTTY Security Alert window
  1. Once connected, enter the username and password that was entered in the advanced settings fo the the Raspberry Pi OS Imager.
PuTTY window showing successful terminal login
  1. Open the Raspberry Pi Configuration Tool by entering the following command:
    sudo raspi-config
  2. Select option 3, Interface Options, and press the Enter key
Raspberry Pi Configuration Tool with Interface Options selected
  1. Select option I3, VNC, and press the Enter key
Raspberry Pi Configuration Tool with VNC option selected
  1. Select Yes, to enable VNC Server, and press the Enter key
Raspberry Pi Configuration Tool confirmation for enabling VNC
  1. Select OK, and press the Enter key
Raspberry Pi Configuration Tool confirmation for enabling VNC
  1. Repeat the steps above to enable the Serial Port and any other interfaces, such as SPI and I2C that may be needed.
  2. Check if there are any other options that you may want to set or execute. Some useful options are Advanced Options > Expand Filesystem and Update.
  3. When done making changes, select Finish to exit the configuration tool.
  4. If you selected Expand Filesystem, you may want to restart the Raspberry Pi by issuing the following command:
    sudo reboot now

VNC Viewer

Check that we are able to connect the Raspberry Pi Desktop using VNC Viewer.

  1. Open VNC Viewer and connect to the hostname for the Raspberry Pi
VNC Connection Window
  1. If this is the first time you are connecting the Raspberry Pi, you will see an Identity Check dialog. Click the “Continue” button.
VNC Identity Check dialog
  1. Enter the Raspberry Pi username and password, then click the “OK” button.
VNC Viewer prompt for username and password
  1. If everything went correctly, you will be presented with the Raspberry Pi desktop.
Raspberry Pi desktop shown in VNC Viewer

By richteel

Software and hardware developer who likes learning new things with a passion of sharing knowledge with others.

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