This version of FM radio with TEA5767 with digital volume use Arduino Uno development board instead Arduino Mega like in previous artilce.
Digital volume in 15 steps is made with MCP4261-502E/P dual digital potentiometer who work as real potentiometer (logarithmic style)...
Step 1: Schematic
This schematic contain:
- Arduino Uno development board or similar (I use VISduino UNO R3, in this case)
- Nokia 5110 display with hand made logical level interface
- FM radio module with TEA5767 chip
- MCP4261-502E/P dual digital potentiomer (SPI control on 8 bit steps)
- breadboard, 4 pushbuttons and few wires
- stereo PC speakers
TEA5767 radio module is put on i2c pins (A4 = SDA & A5 = SCL) and MCP4261 dual digital potentiometer is put on SPI pins: SCK=D13(SCK), SDO=D12(MISO), SDI=D11(MOSI) si CS=D10(SS).
Step 2: Info on Display & Sketch
On Nokia 5110 display (who use PCD8544 controller) I put few informations:
- frequency: value with double characters & units of measure (MHz) with usual characters
- symbol for antenna and small graphic for signal strengh
- graphic for mono and stereo signal and volume steps
My original sketch is put on Github: TEA5767_eeprom_i2c_lcdNokia5110_digitalvolume_3m3.ino.
Value for frequency and value for step volume is stored in EEPROM memory of microcontroller ATmega 328..