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How does a microcontroller work with a RF transmitter?
Signals from the keypad are fed to microcontroller AT89C2051, which, in turn, is interfaced to the RF transmitter through encoder HT12E. The microcontroller continuously reads the status of the keys on the keypad. When any key is pressed, data is passed to the encoder and then to the RF transmitter from where it is transmitted.
How does RF based multiple device control work?
Fig. 1 shows the block diagram for RF-based multiple device control using microcontroller. Signals from the keypad are fed to microcontroller AT89C2051, which, in turn, is interfaced to the RF transmitter through encoder HT12E. The microcontroller continuously reads the status of the keys on the keypad.
What is the C code on a RF transmitter?
The first code is for the RF transmitter circuit microcontroller. The transmitter circuit has 4 push buttons: B1, B2, B3 and B4. Each button sends a code through the RF transmitter as follows (32-bit codes): The full C code is below.
How much voltage do you need for a RF transmitter?
The RF transmitter can be powered from 3 to 12V depending on the range required (more voltage —> more transmission range). In this RF project NEC protocol is used to send data from the transmitter circuit to the receiver circuit. More details about the NEC protocol and how to decode it using PIC16F887 in the following topic:
How to connect nRF24L01 to PIC microcontroller?
Schematic Used to Connect the nRF24L01 With PIC18F46K22 Microcontroller The complete schematic diagram to make the PIC18F6K22 based SPI Communication Test Circuit is shown below. Note: The nRF24L01 module is sensitive to power supply noise. Therefore, it is always a good idea to include a decoupling capacitor in the power supply line.
How are RF signals converted to serial format?
The encoder converts the parallel signals to serial format and transfers them through the RF transmitter at a rate of 1 to 10kbps. The signals are decoded back to parallel signals by the decoder IC HT12D after being received by the receiver. The signals after being inverted are then applied to the motor driver IC, to drive the motor.