mrobosub-esp32

Motor driver code using ESP32

How to install the Firmware onto the ESP32-S3

The general workflow goes as such.

1. Install esptool onto your laptop (preferably in a virtual environment).
2. Download the firmware onto your computer (.bin format)
3. Flash the firmware to the computer
4. (Optional) Verify that the firmware was successfully flashed.

1. Install esptool

esptool is a Python package. As such, first ensure that you have a recent version of python installed on your device and is on your path.

NOTE: For Windows users, I have found it easier to use a Python environment on WINDOWS and not on WSL because you have to do some setup in order to make the Serial ports accessible via WSL.

Create a virtual environment on Mac or Linux

python3 -m venv .venv

You may need to install a package (via brew or apt) for virtual environments. On Ubuntu it's

sudo apt update && sudo apt upgrade -y
sudo apt install python3-venv -y

To load in (or to use the proper lingo, source) the virtual environment, run in the top level directory:

source .venv/bin/activate

Create a virtual environment on Windows

python -m venv .venv

To source the virtual environment, run in the top level directory:

.\.venv\Scripts\activate.bat

NOTE: I needed to expose the <Python Path>\Scripts directory to my path in order to actually be able to run esptool.exe from the command line.

Install the esptool PIP package

With the virtual environment sourced, run these lines on Mac/Linux:

python3 -m pip install esptool

On Windows:

python -m pip install esptool

NOTE: On Windows, the esptool application will be accessible via esptool.exe.

Erase any existing firmware

Connect the ESP32 via USB.

Next, on a Linux environment (I can't speak to Mac for this one), check to see if you can see the Serial device. To do this, look at the /dev/ folder.

Try plugging in and out the USB device and see if a new /dev/ttyACM* device or similar is loaded as a result of connecting the device to your machine.

On a Windows machine, you can use the Device Manager. Look under "Ports (COM & LPT)", you should see a new device once it is plugged in. It should be specified as a COM port.

Next, in a terminal, run the following line (use the .exe for a Windows machine).

esptool[.exe] erase_flash

You may need to specify the Serial port using --port <PORT> on the above line.

NOTE: If you encounter an issue connecting to the Serial port, try these tips. First,ensure no Arduino IDE instances are open. Next, load the board in BOOT mode by holding down the "B" button before plugging in the device to your computer, and only after that releasing the "B" button.

2. Download the Firmware

Download the .bin file from this site.

3. Flash the Firmware to the ESP

Next, we can use the esptool command from the terminal to flash the ESP as follows:

esptool[.exe] write_flash 0 <PATH TO ESP32_FIRMWARE_FILE>

Again you may need to specify a Serial (/dev/ttyACM* on Linux/Mac or COM* on Windows) port.

(Optional) 4. Verify that the Firmware flashed correctly

To do this we will connect to the ESP device using Serial.

For a cross-platform experience, I recommend using Thonny. However, I used PuTTY since I am on a Windows device.

How to connect using PuTTY

1. Specify Serial under Connection type.
2. Specify the Serial port as whichever COM port you find in Device Manager.
3. Set the Speed (which is the BAUD rate) as 115200.
4. Click open.

You should now be able to see a MicroPython terminal open.

Try running

import machine
machine.freq()

If you see something, then this is a success!

Authors

• Zayn Baig
• Colten Germundson