Introduction: Read and Write From Serial Port With Raspberry Pi Using Wemos

Communicating with a Raspberry Pi using a Wemos D1 mini R2.

Step 1: Step 1: Flash Wemos D1 R2 Mini

Upload following code to the Wemos D1 R2 mini:

* ESP8266 Deep sleep mode


void setup() {



void loop() {


Step 2: Step 2: Disabling Console Service on the Raspberry Pi

Disable serial-getty service.

sudo systemctl disable serial-getty@ttyS0.service

Open “/boot/cmdline.txt”.

sudo nano /boot/cmdline.txt

Remove “console=serial0,115200”, then save the file.


sudo reboot

Step 3: Step 3: Connect Raspberry Pi With Wemos D1 R2 Mini

RX <--> RX

TX <--> TX

GND <--> GND

Step 4: Step 4: Upload Python Script

Run following code on your Raspberry Pi:

import time
import serial

ser = serial.Serial(

port='/dev/ttyUSB0', baudrate = 9600, parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE, bytesize=serial.EIGHTBITS, timeout=1 ) counter=0

while 1: x=ser.readline() print x


Step 5: Step 5: Input Serial Data in Putty

Write serial data in Putty and see the echo on the Raspberry Pi.