Blinky ESP32-S3 with Micropython

dev board ESP32-S3-DevKitC-1
chip ESP32-S3-WROOM-1-N8R2
features blinky led esp32s3 micropython ampy

Before starting


Ensure the following dependancies are downloaded and available:

Buy the components


Download code
from machine import Pin
import time
led_pin = 5  # Default on-board RGB LED GPIO48 does not work

led = Pin(led_pin, Pin.OUT)
for i in range(10):
  print("Blink ", i+1)


.PHONY: help default upload log

default: upload

help: ## Show help message
	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m\033[0m\n"} /^[$$()% 0-9a-zA-Z_-]+:.*?##/ { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)

upload: ## Erase flash and then upload the micropython binary
	@echo "Ensure you plug in the board into the USB port"
	@ls /dev/cu.* --chip esp32s3 --port $(UPLOAD_PORT) erase_flash --chip esp32s3 --port $(UPLOAD_PORT) write_flash -z 0 $(BIN_FILENAME)

log: ## Access the serial monitor with ampy
	@ls /dev/cu.*
	@echo "Ensure you plug in the board into the UART port"
	ampy --port $(SERIAL_PORT) run $(PYTHON_FILE)

	@ls /dev/cu.*
	@echo "Ensure you plug in the board into the UART port" --port $(SERIAL_PORT) erase_flash
	@echo "Flash in ESP-IDF blinky"


A photo of the actual setup.

Blinky ESP32-S3 with Micropython prototype


Wire up the hardware accordingly

Blinky ESP32-S3 with Micropython schematic

Serial console

Serial output from the firmware.

Blinky ESP32-S3 with Micropython serial console

Blinky ESP32-S3 with Micropython browser

Use GPIO5 to add a simple external LED



The default on-board RGB LED GPIO48 does not work with the blinky code. Hence, wire up a simple LED and resistor to GPIO5 of the board.

Upload Micropython binary

  1. Plug in the board via the USB port to know the port number
     $ ls /dev/cu.*
     /dev/cu.Bluetooth-Incoming-Port  /dev/cu.usbmodem14101
  2. Download the *.bin file for the board GENERIC_S3-20220618-v1.19.1.bin
  3. Erase the entire flash
     $ --chip esp32s3 --port /dev/cu.usbmodem14101 erase_flash
     Serial port /dev/cu.usbmodem14101
     Chip is ESP32-S3 (revision v0.1)
     Features: WiFi, BLE
     Crystal is 40MHz
     MAC: 7c:df:a1:e2:79:08
     Uploading stub...
     Running stub...
     Stub running...
     Erasing flash (this may take a while)...
     Chip erase completed successfully in 21.5s
     Hard resetting via RTS pin...
  4. Flash the firmware starting at address 0
     $ --chip esp32s3 --port /dev/cu.usbmodem14101 write_flash -z 0 GENERIC_S3-20220618-v1.19.1.bin

Access the Serial monitor with the Python code

  1. Download ampy and ensure it is available
     ampy --help
  2. Plug in the board through the UART port
  3. Check the port number of the board
     ls /dev/cu.*
     /dev/cu.Bluetooth-Incoming-Port  /dev/cu.SLAB_USBtoUART  /dev/cu.usbserial-1410
  4. Run the python script
     ampy --port /dev/cu.usbserial-1410 run

Rollback from Micropython to Arduino

  1. Follow the rollback steps to erase the flash.
  2. Flash in blinky with ESP-IDF.
  3. Flash in blinky with Arduino.