046 – MicroPython TechNotes: RF433 Transceivers

 

In this article, I will tackle how you can use an RF433 transceiver modules with ESP32 using MicroPython.

 

RF433 transmitter and receiver modules uses a radio frequency of 433 MHz which is under the Industrial, Scientific, and Medical bandwidth or ISM band for short.

 

The RF433 transmitter and receiver module both have 3 pins which are (1) G for the ground pin, (2) V for the supply voltage, and (3) S – for the signal pin or data pin. In receiver module, S pin serves as the receive data pin while in transmitter module, S pin serves as the transmitter data pin.

 

To follow this lesson, you will need the following:

1. An ESP32 development board, 1 for the transmitter side and another 1 for the receiver side.

2. A Gorillacell ESP32 shield, 2 pieces for both side of the circuit. This component is optional, you may use a breadboard instead if you want. Gorillacell ESP32 shield simplifies circuit connection.

3. A 3-pin dupont jumper wires, 2 pieces for both side of the circuit.

4. The RF433 transceivers, the receiver and the transmitter module.

 

Since I don’t have prior knowledge in using an RF433 transceiver modules so I did some quick research in the internet. I found this video https://www.youtube.com/watch?v=98tYLEnevfA where he demonstrates the use of the module without using any microcontroller. You might want to jump to 2:23 timestamp to just watch the demonstration.

 

 

I have the exact components, so I followed the circuit but it is a bit clunky. It easily picks interference and it is not working properly.

 

 

 

 

 

If you have any concern regarding this video, please write your question in the comment box.

 

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Thank you and have a good days ahead.

 

See you,

– George Bantique | tech.to.tinker@gmail.com

 

# More details can be found in TechToTinker.blogspot.com 
# George Bantique | tech.to.tinker@gmail.com

from machine import Pin
from time import sleep_ms

transmit = Pin(23, Pin.OUT)
sw = Pin(0, Pin.IN)

while True:
    transmit.value(not transmit.value())
    sleep_ms(50)

 

# More details can be found in TechToTinker.blogspot.com 
# George Bantique | tech.to.tinker@gmail.com

from machine import Pin
from time import sleep_ms

receive = Pin(23, Pin.IN)
led = Pin(2, Pin.OUT)

while True:
    led.value(receive.value())
    sleep_ms(50)

 

# More details can be found in TechToTinker.blogspot.com 
# George Bantique | tech.to.tinker@gmail.com

from machine import Pin
from machine import UART

tx = UART(2, baudrate=9600, tx=23, rx=25)

# tx.write('This is a test messagern')

 

# More details can be found in TechToTinker.blogspot.com 
# George Bantique | tech.to.tinker@gmail.com

from machine import Pin
from machine import UART

rx = UART(2, baudrate=9600, tx=25, rx=23)

# print(rx.read())
while True:
    if rx.any():
        print(rx.read())

 

# More details can be found in TechToTinker.blogspot.com 
# George Bantique | tech.to.tinker@gmail.com

from machine import Pin
from time import sleep_ms

transmit = Pin(23, Pin.OUT)
sw = Pin(0, Pin.IN)
var_sw = 1

while True:
    if sw.value()==0:       # means, sw is pressed!
        var_sw = not var_sw # toggle the state of variable
    transmit.value(var_sw)  # send it to the radio
    sleep_ms(50)

 

 

1. Purchase your Gorillacell ESP32 development kits:

    https://gorillacell.kr/

 

2. Video showing the use of RF433 transceiver modules without an MCU:

    https://www.youtube.com/watch?v=98tYLEnevfA/