Week 9

I prepared to use the ISP programmer (made by me earlier) or try the AVR-ISP-MK2 programmer for flashing, but while I was looking for information about the Raspberry Pi bundle and Attiny85 microcontroller I realized that I can use Raspberry directly as a programmer through the SPI interface (on GPIO pins)! Very interesting approach, I wanted to try it at once

By default, SPI is disabled and I had to enable it in the settings

After that, I found the information that for convenient work with GPIO outputs I will need the library WiringPI

After that, I need to physically connect Attiny to the specific GPIO pins, and I found the following matching table

sudo gpio -g mode 22 out
sudo gpio -g write 22 0
sudo avrdude -p t85 -P /dev/spidev0.0 -c linuxspi -b 10000
sudo gpio -g write 22 1

After I’ve connected everything and checked the connection with this command, I have an error.

I realized I had forgotten to connect the resistors into the circuit and added them. After that everything worked out correctly

After I’ve connected everything, I need to write a program in C and create a Makefile - a special descriptor that allows you to compile the code and upload it to the microcontroller.

The program is very simple - it inverts the signal on all microcontroller ports every second

#define F_CPU 1000000L
#include 
#include 

int main(void)
{
DDRB = 0xFF; // PORTB is output, all pins
PORTB = 0x00; // Make pins low to start

for (;;) {
PORTB ^= 0xFF; // invert all the pins
_delay_ms(1000); // wait some time
}
return 0;

Program Makefile

Once the code has been successfully loaded into the microcontroller’s memory, you can make the circuit standalone by adding a regular battery