Week 09. Embedded Programming¶

This week we learnt about embedded programming.
And the assignment includes:
- individual assignment:
(1) read a micro-controller data sheet, for mine, I read the data sheet of ATtiny44.
(2) program your board (aka. the board I made last week) to do something with as many different programming languages and programming environments as possible.
- group assignment: compare the performance and development workflows for other architectures.

Read the data sheet¶

I read the data sheet of ATtiny44, which is consisted of 286 pages.

Here is the main point that I learned from reading the data sheet.

(Pinout of ATtiny24A/44A/84A, image credit: Atmel)

From the pinout part of the Datasheet, I learned that the pins for my button is Pin2, and LED is Pin3, which will be used in the code when I define my input and output pins.

Program the board¶

This is the board I designed in Week 07 Electronics Design. And this week, I am going to program it!

ATtiny using Arduino IDE¶

I connected my board to the USBtiny and then connected to my MacBook.

Open the Arduino IDE.

I already added ATtiny as the board in Week 12 Output Devices, so I do have it by default now.

I chose the right board, processor, clock and programmer (as shown in the image below).

And click “Tool => Burn bootloader”, it was successful!

By referring to the code of Seeed Grove Button, I wrote the code to use button to control the LED. I checked my design file and the datasheet, my button is connected to pin PA2, and LED is connected to pin PA3 of ATtiny44.

So I used the following code in Arduino IDE and upload.

const int buttonPin = PA2;     // the number of the pushbutton pin
const int ledPin =  PA3;      // the number of the LED pin

// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

void setup() {
    // initialize the LED pin as an output:
    pinMode(ledPin, OUTPUT);
    // initialize the pushbutton pin as an input:
    pinMode(buttonPin, INPUT);
}

void loop(){
    // read the state of the pushbutton value:
    buttonState = digitalRead(buttonPin);

    // check if the pushbutton is pressed.
    // if it is, the buttonState is HIGH:
    if (buttonState == HIGH) {
        // turn LED on:
        digitalWrite(ledPin, HIGH);
    }
    else {
        // turn LED off:
        digitalWrite(ledPin, LOW);
    }
}

It was uploaded succesfully, and when I pressed the button, the LED lighted up, when I released the button, the LED was off. You can see the video below.

ATtiny using Make and Makefiles¶

First of all, I downloaded the hello.ftdi.44.echo.c and the hello.ftdi.44.echo.c.make to the desktop of my laptop.

Now I connect my hello echo board with the USBtinyISP and the laptop.

I opened my terminal and started programming.

STEP 1: locate the above-downloaded files by putting the following code in the terminal and press ‘enter/return’ key. (My files are on my desktop, if your files are in a different location, you need to change the following code accordingly).

cd Desktop/

STEP 2: put in the following code, and press ‘enter/return’ key

make -f hello.ftdi.44.echo.c.make

You can see the screenshot below for STEP 1 & 2.

STEP 3: put in the following code, and press ‘enter/return’ key, and it will require you to enter your system’s password.

sudo make -f hello.ftdi.44.echo.c.make program-usbtiny-fuses

It was successful!

I also tried to program the board to make it blink 3 times when push the button once. Basically by changing the code a little bit, and I can use the button to control the LED differently, including the number of blinks, the duration of LED on, the time between each blink etc.

One push, 3 blinks: each blink‘s duration is different

I used the following code.

const int buttonPin = PA2;     // the number of the pushbutton pin
const int ledPin =  PA3;      // the number of the LED pin


// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

void setup() {
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT);
}

void loop() {

  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed.
  // if it is, the buttonState is HIGH:
  if (buttonState == HIGH) {
    // turn LED on:
    digitalWrite(ledPin, HIGH);
    delay(100);
    digitalWrite(ledPin, LOW);
    delay(10);

    digitalWrite(ledPin, HIGH);
    delay(200);
    digitalWrite(ledPin, LOW);
    delay(10);

    digitalWrite(ledPin, HIGH);
    delay(300);
    digitalWrite(ledPin, LOW);
    delay(10);

  }
  else {
    // turn LED off:
    digitalWrite(ledPin, LOW);
  }
}

And you can see the results in the video below.

One push, 3 blinks: each blink‘s duration is the same