Mixing Arduino with MicroPython on ESP8266

Table of Contents#

1. Fundamental Concepts
2. Usage Methods
3. Common Practices
4. Best Practices
5. Conclusion
6. References

Fundamental Concepts#

Arduino#

Arduino is an open - source electronics platform based on easy - to - use hardware and software. It consists of a microcontroller board and an integrated development environment (IDE). The Arduino IDE uses a simplified version of C/C++ for programming, and there are numerous libraries available for different sensors, actuators, and communication protocols.

MicroPython#

MicroPython is a lean and efficient implementation of the Python 3 programming language that includes a small subset of the Python standard library and is optimized to run on microcontrollers. It provides a more intuitive and rapid - development approach compared to traditional low - level languages.

ESP8266#

The ESP8266 is a low - cost Wi - Fi microcontroller chip with full TCP/IP stack and microcontroller capabilities. It can be programmed using Arduino IDE or MicroPython, making it a popular choice for IoT projects.

Mixing Arduino and MicroPython on ESP8266#

The idea behind mixing these technologies is to use Arduino libraries for tasks that require low - level hardware control, such as reading data from a specific sensor using an Arduino library. At the same time, MicroPython can be used for high - level tasks like network communication, data processing, and interaction with cloud services.

Usage Methods#

Setting up the Environment#

1. Installing Arduino IDE: Download and install the Arduino IDE from the official website.
2. Adding ESP8266 Support: In the Arduino IDE, go to File > Preferences. Add the ESP8266 board manager URL http://arduino.esp8266.com/stable/package_esp8266com_index.json to the “Additional Boards Manager URLs” field. Then, go to Tools > Board > Boards Manager, search for “esp8266”, and install the ESP8266 platform.
3. Flashing MicroPython on ESP8266:
   • Download the MicroPython firmware for ESP8266 from the official MicroPython website.
   • Use a tool like esptool.py to flash the firmware onto the ESP8266. For example, if you have the firmware file named esp8266-20220117-v1.18.bin, you can use the following command:

esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect 0 esp8266-20220117-v1.18.bin

Using Arduino Libraries in MicroPython#

Although MicroPython doesn't directly support Arduino libraries, you can use the Arduino IDE to write a small sketch that uses the library and then communicate with the ESP8266 running MicroPython. For example, if you want to use an Arduino library to read data from a DHT11 temperature and humidity sensor:

1. Arduino Sketch:

#include <DHT.h>
 
#define DHTPIN 2
#define DHTTYPE DHT11
 
DHT dht(DHTPIN, DHTTYPE);
 
void setup() {
  Serial.begin(115200);
  dht.begin();
}
 
void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
 
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
 
  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.println(" *C");
 
  delay(2000);
}

2. MicroPython Code to Read Serial Data:

import machine
import time
 
uart = machine.UART(0, 115200)
 
while True:
    if uart.any():
        data = uart.readline()
        print(data.decode())
    time.sleep(1)

Common Practices#

Data Sharing between Arduino and MicroPython#

• Serial Communication: As shown in the previous example, serial communication is a simple and effective way to share data between an Arduino sketch and a MicroPython script running on the ESP8266.
• External Storage: If you need to share larger amounts of data, you can use external storage like an SD card. The Arduino sketch can write data to the SD card, and the MicroPython script can read it.

Error Handling#

• Timeout Mechanisms: When using serial communication, it's important to implement timeout mechanisms to avoid waiting indefinitely for data. For example, in the MicroPython code above, we can add a timeout to the uart.any() check.

import machine
import time
 
uart = machine.UART(0, 115200)
timeout = 5  # seconds
start_time = time.time()
 
while True:
    if uart.any():
        data = uart.readline()
        print(data.decode())
        start_time = time.time()
    if time.time() - start_time > timeout:
        print("No data received for 5 seconds.")
        break
    time.sleep(1)

Best Practices#

Code Modularity#

• Separate Concerns: Keep the Arduino code focused on hardware - specific tasks and the MicroPython code for high - level tasks. This makes the code easier to understand, maintain, and debug.
• Use Functions and Classes: In both Arduino and MicroPython, use functions and classes to organize your code. For example, in MicroPython, you can create a class to handle serial communication.

import machine
import time
 
class SerialComm:
    def __init__(self, baudrate=115200):
        self.uart = machine.UART(0, baudrate)
 
    def read_data(self, timeout=5):
        start_time = time.time()
        while True:
            if self.uart.any():
                data = self.uart.readline()
                return data.decode()
            if time.time() - start_time > timeout:
                return None
            time.sleep(1)
 
 
comm = SerialComm()
data = comm.read_data()
if data:
    print(data)
else:
    print("No data received within timeout.")

Power Management#

• Sleep Modes: The ESP8266 has different sleep modes that can be used to conserve power. In MicroPython, you can use the machine.deepsleep() function to put the device into deep sleep mode.

import machine
import time
 
# Do some work
time.sleep(2)
 
# Go to deep sleep for 10 seconds
machine.deepsleep(10000)

Conclusion#

Mixing Arduino with MicroPython on the ESP8266 is a powerful approach that combines the simplicity of Arduino libraries with the flexibility of Python programming. By understanding the fundamental concepts, following the usage methods, common practices, and best practices, developers can create more efficient and robust IoT applications. Whether you are a beginner or an experienced developer, this combination can open up new possibilities in your embedded systems and IoT projects.

References#

• Arduino official website: https://www.arduino.cc/
• MicroPython official website: https://micropython.org/
• ESP8266 documentation: https://docs.espressif.com/projects/esp8266 - rtos - sdk/en/latest/
• esptool.py repository: https://github.com/espressif/esptool