RC transmitter for cars, boats, tanks and simple model airplanes

Simple surface 5 channel RC transmitter. The hardware includes nRF24L01+ transceiver and ATmega328P processor. Telemetry monitors receiver voltage using LED indication. The code is Arduino.

This RC transmitter works with RC receiver from my repository RX_nRF24_Motor_Servo

Thank you to "Phil_G" http://www.singlechannel.co.uk for the calibration and reverse routine I used in the code.

The firmware includes

LED mode:

• Normal mode = LED TX is lit
• TX battery voltage 1S LiPo (4.2V) < TX monitored voltage = TX LED flash at a interval of 0.2s
• RX battery voltage 1S LiPo (4.2V) < RX monitored voltage = TX, RX LEDs flash at a interval of 0.5s
• RX receiver off or signal loss = TX LED flash at a interval of 0.1s

Calibration:

• Hold calibration button, switch transmitter TX on, still holding calibration button move all controls to extremes including auxilliary pots.
• Center all controls and aux pots.
• Release calibration button (saved to eeprom).

Servo reversing:

• To reverse the desired channel, hold the joystick in the end position and turn on the TX transmitter (saved to eeprom).

Arduino pins

A0 - joystick 1
A1 - joystick 2
A2 - joystick 3
A3 - joystick 4
A4 - potentiometer 5

D2 - LED
D4 - calibration button (I had to add a 10k resistor -> VCC even when the internal INPUT_PULLUP is activated)
A7 - input TX battery

nRF24L01:
D9  - CE
D10 - CSN
D11 - MOSI
D12 - MISO
D13 - SCK

Used libraries

• <RF24.h> https://github.com/nRF24/RF24
• <EEPROM.h> Arduino standard library
• <SPI.h> Arduino standard library