Week 14

I’ve always dreamt of making my own hands on electronics that can interact without wires. So I decided this week to make boards that will communicate on 433 MHz radio channel.

Architecturally, the system consists of a receiver and a transmitter. There will be 4 buttons on the transmitter and 4 LEDs on the receiver. Each LED should correspond to its own button and light up when the corresponding button is pressed.

Our lab had a 433MHz transceiver kit, which I decided to use.

Link to kit is here: https://www.chipdip.ru/product/433mhz-kit-transceiver?from=suggest_product

I decided to try the Attiny85 microcontroller, there is just more memory than in Attiny45, the rest is identical.

Link to Attiny85 datasheed is here: https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-2586-AVR-8-bit-Microcontroller-ATtiny25-ATtiny45-ATtiny85_Datasheet.pdf

When I started to design in Eagle, again, just like Input devices week, I had to use another items with the same footprint as the 433Mhz transmitter and receiver. Additionally, I put serial interface on receiver, to be able to connect it to PC.

Eagle schematic for transmitter

Eagle schematic for receiver

Eagle board for transmitter

Eagle board for receiver

In our laboratory we decided to use paste and stencils for soldering, it is very interesting and it turns out to be a very precise application of paste on the board. So I sliced the stencils with a plotter and soldered all the elements onto the board.

And only here I realized that I didn’t have SPI connectors for programming Attiny!!