This library is originally written in Arduino sketch by Kiril Zyapkov. This library ported in micropython also allows an ESP8266/ESP32 module with the HSPI port available to become an AVR In-System Programmer.
The ESP8266/ESP32 module connects to the AVR target chip via the standard 6-pin AVR "Recommended In-System Programming Interface Connector Layout" as seen in AVR910 among other places.
If the AVR target is powered by a different Vcc than what powers your ESP8266/ESP32 chip, you must provide voltage level shifting or some other form of buffers. Exposing the pins of ESP8266/ESP32 to anything larger than 3.6V will damage it.
Connections are as follows:
| ESP8266/32 | AVR / SPI |
|---|---|
| GPIO12 | MISO |
| GPIO13 | MOSI |
| GPIO14 | SCK |
| any* | RESET |
For RESET use a GPIO other than 0, 2, 12 and 15 (bootselect pins), and apply an external pullup/down so that the target is normally running.
See the included example (MicroPython_Wifi_AVRISP.py). In short:
import ESPAVRISP
TCP_PORT = 328
RESET_PIN = 5
# Create the programmer object
avrprog = ESPAVRISP.ESPAVRISP(TCP_PORT, RESET_PIN)
# ... with custom SPI frequency
avrprog = ESPAVRISP.ESPAVRISP(TCP_PORT, RESET_PIN, 300000)
while True:
# Check current connection state, but don't perform any actions
state = avrprog.update()
# Serve the pending connection, execute STK500 commands
if state != ESPAVRISP.AVRISP_STATE_IDLE:
avrprog.serve()
This library started off from the source of ArduinoISP "sketch" included with the Arduino IDE:
ArduinoISP version 04m3
Copyright (c) 2008-2011 Randall Bohn
If you require a license, see
http://www.opensource.org/licenses/bsd-license.php
Support for TCP on ESP8266
Copyright (c) Kiril Zyapkov <kiril@robotev.com>.
Port in MicroPython on ESP8266/ESP32
Copyright (c) tab4moji <tab4moji@gmail.com>.