Embedded Programming

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Program your board to do something

In this section we are going to program the isp boad done in week 5 and the pcb board done in week 7. In this case we will need the following.

• The FabISP Programmer board
• 6-Pin 2x3 Header connetor bet
• The pbc board from week 7 (mutant fish pcb)
• the FTDI Cable

The easy way (arduino)

The first step was to understand what we actually had to create in oder to actually wirte, what to write inside the atmega microcontroller. We had to aquire 3 things:

• 1. Aquire the fuses in order to properly configure the microprocessor
• 2. Find the Microcontroller's name to actually adress it in all future instructions through git.
• 3. Find the correct pins the pic is connected to from the schematic in order to adress it and program the atmel with them in mind. I decided to program i C and aduino cause I didnt really know how much harder it was.
• Getting this things we are able to program the pcb to do something. Like blinking the light.

The fuses: I understood them as a gate keepers for certain rooms to enter inside the Atmega processor depending on what "guests" you might plann to invite into the microcontroller. So for example if Ill be using a 20 hz ozolator (Ext. Crystal Osc; frequency 8,0 - Mhz, start-up time PWEDWN/RESET: 258 CK/14CK + 4,1 ms;), and will require to reset the microcontorller at some point (un-check "BOOT REST")

The final Output we find under Current settings as hexadecimal digits. In this case:

• Low:0xE2
• High:0xD9
• Extended:0xFF

The above digits will prime the microcontroller to work in the way it should require. "open the correct doors"

Below Im entering the Hexa code fiuses in order to set the microcontroller up. We later upload this code into the microcontroller and later we actually the controller into doing what we need.

To find the Atmega 328p code to set up the .make file, we search the git with the following command: "avrdude -c attiny45 t" that is telling the microcontroller's current operating system to tell what are all the code equivalents devices it could read.. and we find Atmega328p = m328. We replace this code to the Attiny45 previous code.

Insert part where everything was not cool and i had to redo de microprocessor pbc

In order to find if everything works properly, I opeed git. And typed : avrdude -c attiny45 -p m328p

In this case I strugled because the behaviour of the git ansers where erratic, It started as: avrdude.exe:
"AVR device initialized and ready to accept instruction
later it showed: "ardude.exe: initialization failed, rc=-1

I looked over the fuses, and got nothing wrong. I had forgot to copy the bootloader files inside the arduino directory.

Find the zip file here I found the files from Edu

After that It was still not working, and it was strange as everything seemed in order. I took some drastic measures and: 1. Re-installed the Arduino IED 2. Gave the Mutant fish a Bath in Alcohol (in case something might be messing the connections.) With close help of alex the ISP finally programed the Mutant PCB.

As a result of this de-bugging the final program was finally working.

					    
					        
					        #define F_CPU 2000000UL  //Frecuencia de cristal
#include  <avr/io.h> //libreria para entradas y salidas
#include <util/delay.h> //call librari that you are able to create delays

#define retardo 1000 // define variable
int main (void)
{
	/* set (PB5) of PORT for output */
	//DORB = (1<<PB5)
	DDRC = (1<<PC0); //configura como salida
	
	while(1)
	{
		PORTC = 0b00000001; //se enciende el led
		_delay_ms(retardo);
		PORTC = 0b00000000; //se apaga el led
		_delay_ms(retardo);
	}
		
	
}