Espressif

See also ESP8266 and ESP-C3.

Espressif modules and boards

Hardware

ESP-C3-12F - These are in the old ESP12F form factor but have a RISC-V processor. I will put them in a page on the C3, here ESP-C3.

ESP12F and programmer, see docs at Amazon

Wemos D1 R1 - ESP8266 board in Arduino form factor. Purchased from MPJA for about $13, available on eBay for $7.

Espressif WROVER-DEVKITC-VIE boards (2) from Digikey ($11). Great except they are too wide to use on a breadboard. This device has 520KB RAM + 4MB Flash + 8MB PSRAM making it a good choice for Micropython.

I have a some Home control stuff deployed around my house that's based on ESP8266 chips including FEIT dimmers and Martin Jerry switches. I intend to reflash them all soon to get them off the IoT and onto the local network. There are more details on the ESP8266 page.

ESP-PROG / JTAG board. https://www.digikey.com/en/products/detail/espressif-systems/ESP-PROG/10259352 Flash download tools: https://www.espressif.com/en/support/download/other-tools There is no install step, you just run it.

M5 hardware

520 kB RAM, 4MB flash; really not enough RAM to mess around with Micropython.

M5 Atom Matrix grey with 5x5 Neopixel LED matrix and a 6-axis IMU

M5 Atom Echo white, with a speaker and microphone. It also has a Neopixel.

M5StickC

M5StickC orange and wearable. I have a few of these because they are cheap, come with lots of sensors, a tiny 80x160 LCD, and are nicely enclosed in a little case. Also has a 6-axis gyro/accelerometer, and a microphone. Also it can detect alien lifeforms in a 100 meter radius.

It uses an ESP32-PICO-M4 processor with 4MB of RAM. It's supposed to be a wearable so it has a battery. This MCU uses more power than an ESP32S3 if that matters to you.

Initially I set up one with a PIR hat and used it to control a light for about a year. Currently it's offline due to household politics. It works really perfectly for this with an MQTT connection to Home Assistant.

• What can I do with the internal temp sensor? There are sensors in both the PMIC and the MEMS sensors
• What can I do with its RTC? Datasheet https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/docs/datasheet/Stamp/StampTimerPower/RTC8563.pdf
• What can I do with the accel/gyro? Detect vibration or change of direction in a car? Step count? It supports "wake on motion". You can find its orientation by reading the accelerometer. "Down" is usually Z=1g for example.
• What can I do with the mic? Make lights blink? https://www.hackster.io/esikora/audio-visualization-with-esp32-i2s-mic-and-rgb-led-strip-4a251c
• Can I turn off TV's with the IR LED? https://www.hackster.io/alessandro-polselli/turn-m5stickc-into-universal-ir-remote-home-automation-d3ec0d

Internal photos (This "plus" version has bigger screen) https://www.gwendesign.ch/kb/m5stack/m5stickcplus/ and https://www.gwendesign.ch/kb/m5stack/m5stickc/

It has some magnets in it so you can stick it to things! Cool.

Batteries - it has an RTC button cell and a tiny (95mAH) LiPo. More of a UPS than a power supply.

Looks like taking it apart is a waste of time, things are pretty packed in there. Don't bother. Have lots of other ESP32 things already.

Projects

Motion sensor -- I have had one deployed for months in our bedroom, it switches on a light in the evening. Works via MQTT I used a RADAR sensor that is too good, it can see through drywall and picks up motion everywhere. I am switching to PIR sensors soon.

LED strip controller -- working on this soon, to control RGBW strips over WiFi, or maybe I will press on with the Nordic nRF52840's and Zigbee.

Toolchains

Right now it's a blob in my mind so I am here writing this to sort it out. I got some nRF52840's and that's just added to the confusion.

Arduino, Espressif IDF, FreeRTOS Visual Studio Code, PlatformIO

I have been using Arduino but I really want to try out working with RTOS and I want to use VSCode as my IDE, I am getting comfortable with it at work.

There is a tutorial here: https://randomnerdtutorials.com/vs-code-platformio-ide-esp32-esp8266-arduino/

• Visual Studio Code (VSCode) is an IDE. It is far more useful than Arduino's IDE.
• PlatformIO is an extension for VSCode.
• There is also an Espressif IDF extension.

• PlatformIO adds the "alien" icon in the left bar.
• ESP-IDF adds a bunch of tools to the blue bar at the bottom.

VSCode + PlatformIO + Arduino framework

When creating a project with PlatformIO you can pick Arduino as the Framework if you don't need the ESP-IDF platform. I put all my source code in ~/source/platformio/.

I cloned the M5Stack repo https://github.com/m5stack/M5Stack.git The Examples/ are great.

I just built and uploaded a Blink program and it worked flawlessly on the first try. In the blue bar there are build and upload tools. There is a "serial monitor" tool in the blue bar too. Output goes to a Terminal window.

So far I find this experience much better than using Arduino IDE, perhaps because I already use VS Code, also partly because the project is organized more the way I'd want. I like having one window for everything, I've never liked how Arduino opens a new window for each "sketch". Also I never liked the word "sketch", lol.

VSCode + PlatformIO + ESP-IDF framework

I followed this tutorial. https://docs.platformio.org/en/latest/tutorials/espressif32/espidf_debugging_unit_testing_analysis.html#

It worked fine, I tested it on an M5 Atom Matrix. I got a soft AP running.

Libraries

PlatformIO has its own library manager and when you add a library, the library is downloaded and referenced in the platformio.ini in the current project.

So how do I do that?

JTAG debugging

Example of JTAG debugging

JTAG debugging

https://mcuoneclipse.com/2019/10/20/jtag-debugging-the-esp32-with-ft2232-and-openocd/

Books and resources

Neil Kolban

Random Nerd