The circuit posted here is of Arduino FM Receiver using digital radio—receiver module TEA5657 by Philips. Additional of components like audio power amplifier, arduino uno board and LCD module to display station number and frequency. However, for the receiving system to function flawlessly, external components like capacitor, resistor etc. included in the circuit which is obvious necessity.
Circuit Description Arduino FM Receiver Circuit :
The circuit of project Arduino FM Receiver is shown in figure 1. The main or controlling part of the system is arduino uno board which is basically a prototyping platform consisting ATmega 328 microcontroller.
Now talking about receiver module, TEA5767. TEA5767 is a low-voltage fully integrated intermediate frequency (IF) FM stereo radio module. It includes features like stereo and mono output, station scanning, indicating signal strength, adjustment free etc. TEA5767 receiver module operates either in I2C protocol or in 3-wire BUS protocol which can be selected using BUSMODE pin (pin 3). Here, in this project Arduino FM Receiver BUSMODE is grounded because we had used I2C protocol.
Figure : TEA5767
Data pin (pin 2) and clock pin (pin 3) of FM receiver module is connected to analog pin (A4 and A5) of arduino uno board respectively where pin 3 and 6 is grounded as shown in circuit diagram. Output is taken from pin 7 and pin 8 of receiver module for left and right channel respectively.
The output from FM receiver module is given to low power audio amplifier IC (LM386) because the output of radio receiver module is very low and inaudible. Here, in the circuit we had used only left channel output. If you need stereo output you must use another LM386 for right channel output. Variable resistor VR2 is used control the volume in the speaker.
Two resistor R1 and R2 with two Push-to-on switches is used to change the frequency (up and down) respectively in order to change the channel. These two resistors are Pull-up resistor used to control the switch bounce condition.
We all know that the length of antenna must be the size of wavelength. For the project posted here we had used 75cm antenna connected to pin 10 of radio receiver module.
Now let’s talk about software. The software is written and compiled in Arduino IDE environment. You can directly download the software package and uploads in arduino uno board. The package contains the software code with auto scan function and without auto scan function.
For better understanding of code, we had already used comment, but still we had listed some syntax.
- BeginTransmission(0x60); “Starts communication with TEA5767 module where 0x60 is for write and 0x61 is for reading”
- Write(0x00); “For sending data bit by bit in I2C protocol”
Before dealing with this syntax at first, we must know about write mode data sequence.
When station is found it set the RF flag 1 i.e. RF = 1 which is stored at bit 3 where bit 4 is used to store stereo or mono signal strength.
The sentence used to update value is “Buffer[i] = Wire.read();”
- read(); “Read data of write mode data sequence in read mode”
OUTPUT OF LCD
- Shows the frequency stored in buffer (0);
- Display scanning in search mode;
- Shows signal strength stored in buffer (3);
PARTS LIST OF ARDUINO FM RECEIVER CIRCUIT USING TEA5767
|Resistors (all ¼-watt, ± 5% Carbon)|
|R1, R2 = 10 KΩ
R3 = 330 KΩ
R4 = 10 Ω
VR1, VR2 = 10 KΩ preset
|C1 = 22 µF/25V (Electrolytic Capacitor)
C2 = 10 µF/25V (Electrolytic Capacitor)
C3 = 100 µF/25V (Electrolytic Capacitor)
|BOARD1 = Arduino Uno Board
IC1 = LM386 Low-Power Amplifier
FM1 = TEA5767 Digital Radio Receiver Module
LCD1 = 16×2 LCD
|SW1, SW2 = Tactile Switch
BATT.1 = 9V Battery
LS1 = 8-ohm, 0.5W speaker
ANT. = 75cm Hookup Wire Antenna