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() {
ESP.deepSleep(0);  
}
void loop() {
 }

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

Disable serial-getty service.

sudo systemctl disable [e-mail]

Open “/boot/cmdline.txt”.

sudo nano /boot/cmdline.txt

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

Reboot.

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
ssssss

Step 5: Step 5: Input Serial Data in Putty

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