4. Embedded Programming

This week I learned what embedded programming constitutes.

Group assignment: demonstrate and compare the toolchains and development workflows for available embedded architectures

Individual assignment: browse through the data sheet for your microcontroller write a program for a microcontroller, and simulate its operation, to interact (with local input &/or output devices) and communicate (with remote wired or wireless connections) extra credit: test it on a development board extra credit: try different languages &/or development environments

GROUP ASSIGNMENT
You can view our group assignment here!

INDIVIDUAL ASSIGNMENT

Exploring Xiao Rp2040

I went through the RP2040 Datasheet that provides a detailed understanding of the icrocontroller

The name of the chip comes from the following.

This diagram shows the system overview of the RP2040 Microcontroller

Some of the features of rp2040 include:

Dual Cortex M0+ processor cores, up to 133MHz
264kB of embedded SRAM in 6 banks
30 multifunction GPIO
6 dedicated IO for SPI Flash (supporting XIP)
Dedicated hardware for commonly used peripherals
Programmable IO for extended peripheral support
4 channel ADC with internal temperature sensor, 500ksps, 12-bit conversion
USB 1.1 Host/Device

Pinout Diagram

A "pinout diagram" is a diagram or list that shows the arrangement and function of the pins (or terminals) on an electronic component or connector, helping users understand how to connect and interact with the device.
Shown below is the pinout diagram of a xiao rp2040 microcontroller.

The various uses of the pins are explained in the datasheet as shown below:

Each individual GPIO pin can be connected to an internal peripheral via the GPIO functions defined below. Some internal peripheral connections appear in multiple places to allow some system level flexibility. SIO, PIO0 and PIO1 can connect to all GPIO pins and are controlled by software (or software controlled state machines) so can be used to implement many functions.

Understanding Arduino IDE and Micropython

Micropython

MicroPython is a lightweight version of Python designed for microcontrollers, while Arduino IDE is a platform for writing and uploading code to Arduino boards, typically using C/C++.Allows for easy interaction with hardware through GPIO pins, sensors, and actuators.

Arduino IDE

It is a software environment for programming Arduino microcontroller boards. Arduin IDE provides an easy-to-use interface for writing, compiling, and uploading code to the board. It is widely used in hobbyist, DIY, and educational projects for electronics and robotics. It includes very helpful libraries and built-in functions to get started with a program and simplifies hardware interaction.

Programming

This week i tried to learn how to program a microcontroller using Arduino IDE (C/C++) and Thonny (MicroPython).

To understand how to write the code we tried write simple code to function an LED.

Trying out WOKWI

WOKWI is an online simulator for microcontrollers, allowing users to test and debug embedded systems without needing physical hardware. It supports various microcontrollers, including the Raspberry Pi Pico, Arduino boards, and ESP32, along with virtual peripherals like LEDs, buttons, sensors, and serial monitors. i tried to simulate and learn basic codes to work a circuit.

. Open Wokwi and make an account for yourself and add a new project

Select Pico as Microcontroller. Also select the language as Micropython.

Since this was the the first time i was doing this i went with a simple circuit containing a LED that will turn on with a push button switch.

A templete with the raspberry pi board will appear on the screen along with a window on the left for writing the code.

Now we can add components and write codes to simulate an action. Click on the '+' to add components.

We can change the parameters of the components according to what we need. just click on the component and a toolbar pops up where you can set the parameters.

So i placed an LED on to the board and connected its ends to a ground pin and another available pin.

Similarly add a push button switch to the circuit

Now that the components are set up we need to write the code to make it work the way we need it to.

I tried to write the code using micropython.

First we need to import the required libraries into the code using the import command. in this circuit we we need to import pin and time.The Pin function lets us use the GPIO pins from our microcontroller.The sleep function is imported to add a delay to the program.

   from machine import Pin
   from utime import sleep

Now we have to set up the pins and name the variable. Here we need to define that the Led is an Output.We also define the button as an input.

    from machine import Pin
    from utime import sleep
        
    led = Pin(1, Pin.OUT)
    button = Pin(7,Pin.IN,Pin.PULL_UP)

Next we can apply funtions to the code . To make the led turn on when the button is pressed the following code is written .

  from machine import Pin
  from utime import sleep
  
  print("Hello, Pi Pico!")
  
  led = Pin(1, Pin.OUT)
  
  button = Pin(7,Pin.IN,Pin.PULL_UP)
  
  while True:
     
      if button.value() == 0:
          print("Button pressed, LED on")
          led.value (1)
  
         
      else : 
          led.value(0)

The while loop executes a set of statements as long as a condition is true. The if statement executes a code based on whether a certain condition is true or false. The else statement is an alternative code block to execute if the if condition is false.

I also tried adding another blue led and made them turn on/off using the button in various ways. The simulation below shows when the blue led turned on initially and when the button is switched on the red led turns on and the blue led turns off.

    from machine import Pin
    from utime import sleep
    
    print("Hello, Pi Pico!")
    
    led = Pin(5, Pin.OUT)
    led2 = Pin(2,Pin.OUT)
    button = Pin(7,Pin.IN,Pin.PULL_UP)
    
    while True:
       
        if button.value() == 0:
            print("Button pressed, LED on")
            led.value (1)
            led2.value(0)
           
        else : 
            led.value(0)
            led2.value(1)

-->

Using Arduino IDE

I had to install Arduino IDE first as this was my first time using it.

I felt like the interface of this software was quite easy to follow and there was a lot of refrence libraries and example codes to use and follow.

We need to setup the New sketch according to the board that needs to be programmed. Go to tools >> select board >> choose the board you will be programming (in this case Arduino Uno).

I used an Arduino Uno board and attached a power led to it used a example code to blink the LED.To get the example code first go to file >> Examples >> Blink

Next choose the port to which the board is connected.

I tried out some sample codes.

Then just as an exercise i made a code to blink the led when an initialised variable(in this case the variable is 'namita') which is incrementing becomes a multiple of 5

You can compile the sketch to check for any errors made while writing code (such as missing a library or missing out on putting the';" after a declaration ).Then we can upload the code to the board.