Adafruit ESP32-S3 boards

Adafruit have designed several boards based on the Espressif ESP32-S3 Wi-Fi microcontroller modules. These modules have dual 240MHz Xtensa cores, Wi-Fi, and Bluetooth support. These boards have a USB-C connector, and use the ESP32-S3's native CDC USB, avoiding the need for a UART chip. 

Even large serial uploads are now reliable using the latest core, provided you install with the USB Mode: "USB-OTG (TinyUSB)" option, and so these boards can be recommended for use with uLisp.

Boards 

Adafruit ESP32-S3 Feather

Adafruit QT Py ESP32-S3

General features

Installing the ESP32 Arduino core

If you don't already have the ESP32 Arduino Core installed:

  • Add the following URL to the Additional Boards Manager URLs list in the Arduino IDE Preferences dialog box:
https://espressif.github.io/arduino-esp32/package_esp32_index.json
  • In the Arduino IDE search for the ESP32 Arduino core in Boards Manager and install it.

I tested this with core version 3.3.7.

Setting up the Board options

The installation procedure is the same for all of these boards:

  • Select ESP32 Arduino from the Board menu.
  • Select the appropriate Board option:

Adafruit Feather ESP32-S3 2MB PSRAM

Adafruit Feather ESP32-S3 No PSRAM

Adafruit QT Py ESP32-S3 No PSRAM

Adafruit QT Py ESP32-S3 (4M Flash, 2M PSRAM)

  • Set USB Mode: to "USB-OTG (TinyUSB)".
  • Set USB CDC On Boot: to "Enabled".
  • Set Upload Mode: to "USB-OTG CDC (TinyUSB)".
  • Set Partition Scheme to Default 4MB with spiffs.

If the board has PSRAM:

  • Set PSRAM: to "QSPI PSRAM" to use it (recommended), or "Disabled" to disable it.

You can leave the other options at their defaults.

Uploading uLisp

  • Download release 4.9a or later of the ESP version of uLisp from the Download uLisp page.
  • Select the board's USB port from the Port menu.
  • Upload uLisp to the board.

Uploading Lisp programs

To upload a program to uLisp:

  • Select it, including the comment at the top of the program, and do Copy.
  • Click in the Arduino Serial Monitor input field and do Paste, then press Return.

The comment disables echo, which could interfere with the serial upload.

LittleFS and save-image

The ESP32 version of uLisp uses LittleFS to allow you to save the entire workspace on all ESP32 boards using (save-image).

The first time you call save-image LittleFS allocates the file system, and an error may be displayed such as:

./components/esp_littlefs/src/littlefs/lfs.c:1071:error: Corrupted dir pair at {0x0, 0x1}
E (62578) esp_littlefs: mount failed,  (-84)
E (62579) esp_littlefs: Failed to initialize LittleFS

It should subsequently work without error.

If you have previously used the board with an older version of the Arduino ESP32 core and you get the error:

assert failed: lfs_fs_grow_ lfs.c:5263 (block_count >= lfs->block_count)

upload uLisp again after selecting the option:

  • Erase All Flash Before Sketch Upload: "Enabled"

Wi-Fi

All these boards support Wi-Fi. To connect to a Wi-Fi network give the wifi-connect command with the network name and password; for example:

> (wifi-connect "Geronimo" "secret99")
"10.0.1.28"

If successful it will return the IP address you are connected to.

For more examples of using the Wi-Fi features see Wi-Fi examples, and for reference information see Wi-Fi extensions.

NeoPixel

These boards provides a NeoPixel RGB LED on :pin-neopixel. The following program slowly displays the full range of colours on the LED using the rgbledwrite function:

; NeoPixel spectrum

(defun fix (y)
  (setq y (mod y 1536))
  (if (>= y 768) (setq y (- 1535 y)))
  (setq y (max (min (- y 256) 255) 0)))

(defun spectrum ()
  (unwind-protect
      (loop 
       (dotimes (c 1536)
         (rgbledwrite :pin-neopixel (fix (+ c 768)) (fix (+ c 256)) (fix (+ c 1280)))
         (delay 50)))
    (rgbledwrite :pin-neopixel 0 0 0)))

The unwind-protect turns off the LED if you escape from the program.

To run the program enter:

(spectrum)

To exit type a ~.

Sleep

The sleep function can be used to put these boards into light sleep for a specified number of seconds. The current consumption typically drops to 5% of normal power.

Adafruit ESP32-S3 Feather

Adafruit offer two ESP32-S3 Feather boards: the Adafruit ESP32-S3 Feather 8MB Flash No PSRAM [1], and the Adafruit ESP32-S3 Feather 4MB Flash 2MB PSRAM [2]. They adopt the same format as Adafruit's other Feather boards, making them compatible with their Featherwings:

FeatherS3.jpg

I recommend the PSRAM version for use with uLisp.

The boards have a USB-C connector, and use the ESP32-S3's native USB, avoiding the need for a UART chip. They include a JST connector for a Lipo battery, a Lipo charger to allow the battery to be charged from the USB port. Earlier boards have an I2C LC709203 battery monitor chip; in recent boards this has been replaced by the MAX17048. The boards also have a vertical QWIIC/STEMMA QT connector for connecting I2C modules.

LEDs

As with other Feather boards the ESP32-S3 Feather boards have a red LED connected to digital pin 13 which you can flash with the following program:

(defun blink (&optional x)
  (pinmode :led-builtin t)
  (digitalwrite :led-builtin x)
  (delay 1000)
  (blink (not x)))

Run it by typing:

(blink)

Exit by entering ~.

Analogue inputs

The ESP32-S3 Feather boards have 15 analogue inputs, on pins 3 to 6 and 8 to 18.

Serial

The ESP32-S3 Feather boards have one serial port on pin numbers 38 (RX) and 39 (TX).

SPI

The ESP32-S3 Feather boards have one SPI port on pin numbers 42 (SS), 37 (MISO), 35 (MOSI), and 36 (SCK).

I2C

The ESP32-S3 Feather boards have one I2C port on pins 3 (SDA) and 4 (SCL).

Adafruit QT Py ESP32-S3

Adafruit offer two ESP32-S3 QT Py boards: the QT Py ESP32-S3 No PSRAM [3], and the QT Py ESP32-S3 with 2MB PSRAM [4]:

QTPYS3.jpg

They provide 8 MB flash and no PSRAM or 4 MB flash and 2 MB PSRAM respectively. For uLisp I recommend the one with PSRAM.

LEDs

The QT Py ESP32-S3 has no built-in LED, but it does have a NeoPixel RGB LED. To use it see General features above.

Analogue inputs

The QT Py ESP32-S3 boards have 8 analogue inputs, on pins 5 to 9 and 16 to 18.

Analogue outputs

The QT Py ESP32-S3 supports PWM output on any pin using analogwrite.

Serial

The ESP32-S3 QT Py boards have one serial port on pin numbers 16 (RX) and 5 (TX).

SPI

The ESP32-S3 QT Py boards have one SPI port on pin numbers 42 (SS), 37 (MISO), 35  (MOSI), and 36 (SCK).

I2C

The ESP32-S3 QT Py boards have two I2C ports: port 0 on the edge connector on pins 7 (SDA) and 6 (SCL), and port 1 on the STEMMA QT connector on pins 41 (SDA) and 40 (SCL).

  1. ^ Adafruit ESP32-S3 Feather 8MB Flash No PSRAM on Adafruit.
  2. ^ Adafruit QT Py ESP32-S3 with 4MB Flash 2MB PSRAM on Adafruit.
  3. ^ Adafruit QT Py ESP32-S3 No PSRAM on Adafruit.
  4. ^ Adafruit QT Py ESP32-S3 with 2MB PSRAM on Adafruit.

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