SI473X Library for Arduino

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Examples of using the Si4735 Arduino Library on ATtiny85

This folder shows how you can use de Si4735 Arduino Library on the very small ATtiny85. See the examples below.

SI47XX 01 - SI47XX_01_ATTINY85_LCD_16x2_I2C - AM/FM receiver with ATtiny85

This example implements an AM and FM receiver using the ATtiny85 as the master MCU.

The Attiny core board/plataform can be installed using the Arduino IDE boards manager. Insert the URL on board manager.

On menu Preferences, enter the above URL in “Additional Boards Manager URLs; To setup ATtiny85 on Arduino IDE, go to Tools Menu, Board, Board Manager and install “ATTinyCore by Spence Konde”. See also the video How to “SI4735 Arduino Library and ATtiny85”.

See ATTiny Core - 1634, x313, x4, x41, x5, x61, x7, x8 and 828 for Arduino.

See also ATtiny85 pinout.

EEPROM - SI47XX_03_SSB_Tiny4kOLED - SI4735-D60 SSB patch from an external EEPROM

This example shows the use of the external EEPROM. It will transfer the SSB patch content stored in an EEPROM to SI4735-D60. To run this sketch you must have a external I2C EEPROM device configured with your ATtiny85 and the Si4735 devices via i2C bus. The EEPROM must have the patch content generated by the sketch SI47XX_09_SAVE_SSB_PATCH_EEPROM. See folder examples/TOOLS.

ATtiny85 Schematic

The pull-up resistor values may vary depending on the devices connected to the I2C bus. Select the lowest possible resistors. The schematic below show 4.7K for pull-up resistors. However, it can be lower than it.

Schematic ATtiny85 and Si4735


Schematic ATtiny85 and Si4735


The photo below show the Si4730 on adapter board with the basic components suggested by Silicon Labs.

Photo ATtiny85 and Si4730 on Adapter

The photo below shows the Si4730 on adapter board connect attached on a mini breadboard.

Photo ATtiny85 and Si4730 on mini breadboard

The Si4730 and ATtiny85 FM radio prototype.

Photo ATtiny85 and Si4730