6. Embedded Programming

For this week's practice we were asked to write a program for a development board with a microcontroller. This must have exits and entrances. In addition to being able to communicate. And as an extra, use different languages and development environments. To carry out this practice, I used Arduino and Python, in addition to which I designed and manufactured a PCB to connect to the board that we manufactured in week four

The idea for this project was to create a pin-pong type game with several LEDs in a row, this would have nine LEDs and two buttons. I started with the design of the PCB, and once I had the plan, I began the task of making the program. I first started with Arduino since I have used it in the past and having the code ready I just passed it to the Python syntax

Arduino (C++)

Arduino is an open source platform used for creating electronics projects. The Arduino development environment is an easy-to-use software that allows you to write, compile, and upload code to the board's microcontroller. This software is compatible with operating systems such as Windows, macOS and Linux. Programming is done in a language similar to C/C++, which makes it easy to learn and use, especially for those who already have experience in these languages.

Circuit Python

Python is a general-purpose, interpreted, high-level programming language designed with a focus on code readability. It is a multi-paradigm programming language, which means that it supports different programming styles, such as object-oriented, imperative, functional and procedural programming. This makes it extremely flexible and suitable for a wide range of applications. Python runs on a variety of platforms, including Windows, macOS, Linux, and has been ported to Java and .NET in virtual environments.

Syntax comparison

	ARDUINO (C++)	PHYTHON
Control Structures	Opening and closing of keys	Tab hierarchy
Variables	Variable type specification int, float, char, etc	automatically determines the type of variable
Comments	//comment and /more comments/	#comment and '''more commnets'''
Functions	Specify the return	Using def with arguments
Delay	(import time) time.sleep(1) one second	Delay(1000) one second
Input	#define push 25 pinMode(push, INPUT)	x = digitalio.DigitalInOut(board.GP25) push.direction = digitalio.Direction.INPUT
Output	#define led 25 pinMode(led, OUTPUT)	x = digitalio.DigitalInOut(board.GP25) led.direction = digitalio.Direction.OUTPUT
Write	digitalWrite(led,HIGH) digitalWrite(led,LOW)	led.value = True led.value = False
Read	digitalRead(push)	push_value = push.value
Printing	Serial.prinln("hello, wold")	print("hello, wold")

for more information visit the GROUP PAGE

Programming

To start programming our microcontroller, we first need to prepare our microcontroller for the programming language we are going to use. To do this on my SEED XIAO rp2040 microcontroller, you will press the B button on the board and, while keeping it pressed, connect it to the computer. This folder will not appear on the computer. This active the mode bootloader

for Arduino

In this mode, we will open the Arduino program and look for the following option

We will look for the seeed xiao rp2040 board and we will give ok

Now the board recognizes us and we can load the code from the Arduino program.

arduino

for Python

Inside the board folder, we will drag the bootloader for python, and we wait for the folder to open again

The folder should look like this

In mu Editor we will load the code file and that's it, we can load code if you press the save button

mu Editor

Having the program ready and the Bootloader installed on the micro controller. Just upload the code for it to work, the following are the programs I created in Arduino and Python that do exactly the same thing

ARDUINO

In this part of the code, I assign a name to each port of the microcontroller, following the given image.


									//DEFINE PINS-------------------------

									

										#define push1 D0 

										#define push2 D1

										

										#define led1 D2

										#define led2 D3

										#define led3 D4

										#define led4 D5

										#define led5 D6

										#define led6 D7

										#define led7 D8

										#define led8 D9

										#define led9 D10

ARDUINO

Flags will allow the button to detect only one press when it is pushed. The other variables are counters that let us see the state of the game; the 'state' variable indicates whether the main counter starts to increase or decrease.


										//VARIABLES----------------------------------- 

										

										int flag1 = 1;        //flag for the buttons 

										int flag2 = 1; 

										

										int cont = 0;         //main counter to turn on leds 

										int cont_vel = 0;     //counter to determine speed 

										int state = 1;        //counter increases(1) or decreases(0) 

										int game = 0;         //start game 

										int cont_red=0;       //count when you reach the color red

ARDUINO

void setup() is the main configuration of the program. In this, we establish communication and the modes of the pins.
Serial.begin is the speed at which we will communicate with the monitor that Arduino includes, a tool that facilitates communication.
pinMode determines if the pin is an input or output; for buttons, they will be inputs, and for LEDs, they will be outputs.


										void setup() { 


											Serial.begin(9600);          //comunication  

											//PINMODE------------------------------------------- 

											  pinMode(push1,INPUT);        //buttons 

											  pinMode(push2,INPUT); 

										   

											  pinMode(led1,OUTPUT);        //LEDS 

											  pinMode(led2,OUTPUT); 

											  pinMode(led3,OUTPUT); 

											  pinMode(led4,OUTPUT); 

											  pinMode(led5,OUTPUT); 

											  pinMode(led6,OUTPUT); 

											  pinMode(led7,OUTPUT); 

											  pinMode(led8,OUTPUT); 

											  pinMode(led9,OUTPUT); 

										  }

ARDUINO

Here, we create a start for the game. It is necessary to press both buttons for the game to start. It will send a "Start" message. Then it will perform a sequence of turning all the LEDs on and off.


										void loop()  

											//START GAME---------------------------------------- 

											  //press the two buttons to start, small blink and  

											  //I enter the game loop 

											  if ((digitalRead(push1)==1) && (digitalRead(push2)==1)) { 

												game=1; 

												Serial.println("--------START----------"); 

												(digitalWrite(led1,1)); 

												(digitalWrite(led2,1)); 

												(digitalWrite(led3,1)); 

												(digitalWrite(led4,1)); 

												(digitalWrite(led5,1)); 

												(digitalWrite(led6,1)); 

												(digitalWrite(led7,1)); 

												(digitalWrite(led8,1)); 

												(digitalWrite(led9,1)); 

												delay(50); 

												(digitalWrite(led1,0)); 

												(digitalWrite(led2,0)); 

												(digitalWrite(led3,0)); 

												(digitalWrite(led4,0)); 

												(digitalWrite(led5,0)); 

												(digitalWrite(led6,0)); 

												(digitalWrite(led7,0)); 

												(digitalWrite(led8,0)); 

												(digitalWrite(led9,0)); 

												delay(50); 

												state=1; 

											  }

ARDUINO

By pressing both buttons, the 'Game' variable will change to one, and we will enter the game cycle. 'Game Speed' will start at 100, and each time it repeats, it decreases by one. In this way, the internal delay will repeat fewer times, making the game faster.
Here, flags are applied so that the code repeats only once and nothing happens if we keep the first button pressed so that the main counter increases, and the second button will cause it to decrease.


										//GAME LOOP-----------------------------------------  

											while(game==1) 

											//game speed 

											for (int x=100; x>=cont_vel; x--) { 

											delay(2); 

											} 

											//first button with flag, counter increases and 
 
											//speed increases 

											if ((digitalRead(push1)==1) && (flag1==1)) { 

											state=1; 

											cont_vel++; 

											flag1=0; 

											} 

											if((digitalRead(push1)==0) && (flag1==0)){ 

											flag1=1; 

											} 

											//second button with flag, counter decreases   

											//and speed increases 

											if ((digitalRead(push2)==1) && (flag2==1)) { 

											state=0; 

											flag2=0; 

											cont_vel++; 

											} 

											if((digitalRead(push2)==0) && (flag2==0)){ 

											flag2=1; 

											}

ARDUINO

Our main counter has 10 different cases: zero and ten are the limits where if we enter them, we would lose the game. Cases zero and ten will make the LEDs blink, indicating that you lost, and cases one to nine turn on the LEDs independently.


										switch (cont) {  

											//blink and we give up the game 

											case 0: 

											  for (int x=0; x<=5; x++) { 

												(digitalWrite(led1,1)); 

												(digitalWrite(led2,1)); 

												(digitalWrite(led3,1)); 

												(digitalWrite(led4,1)); 

												(digitalWrite(led5,1)); 

												(digitalWrite(led6,1)); 

												(digitalWrite(led7,1)); 

												(digitalWrite(led8,1)); 

												(digitalWrite(led9,1)); 

												delay(100); 

												(digitalWrite(led1,0)); 

												(digitalWrite(led2,0)); 

												(digitalWrite(led3,0)); 

												(digitalWrite(led4,0)); 

												(digitalWrite(led5,0)); 

												(digitalWrite(led6,0)); 

												(digitalWrite(led7,0)); 

												(digitalWrite(led8,0)); 

												(digitalWrite(led9,0)); 

												delay(100); 

											  } 

												game=2;   

											break;


										case 1: 

										(digitalWrite(led1,1)); 

										(digitalWrite(led2,0)); 

										(digitalWrite(led3,0)); 

										(digitalWrite(led4,0)); 

										(digitalWrite(led5,0)); 

										(digitalWrite(led6,0)); 

										(digitalWrite(led7,0)); 

										(digitalWrite(led8,0)); 

										(digitalWrite(led9,0)); 

										cont_red++; 

										Serial.println("red"); 

									  break; 

							          

									  case 2: 

										(digitalWrite(led1,0)); 

										(digitalWrite(led2,1)); 

										(digitalWrite(led3,0)); 

										(digitalWrite(led4,0)); 

										(digitalWrite(led5,0)); 

										(digitalWrite(led6,0)); 

										(digitalWrite(led7,0)); 

										(digitalWrite(led8,0)); 

										(digitalWrite(led9,0)); 

									  break;

PYTHON

In this part, I defined the input and output pins of the ports on the board. In the case of the buttons, we also have to declare the type of button. We declare the pins, as seen in the image.


										#DEFINE PINS-------------------------  

										

										push1 = digitalio.DigitalInOut(board.D0) 

										push1.direction = digitalio.Direction.INPUT 

										push1.pull = digitalio.Pull.DOWN 

										push2 = digitalio.DigitalInOut(board.D1) 

										push2.direction = digitalio.Direction.INPUT 

										push2.pull = digitalio.Pull.DOWN 

 										

										led1 = digitalio.DigitalInOut(board.D2) 

										led1.direction = digitalio.Direction.OUTPUT 

										led2 = digitalio.DigitalInOut(board.D3) 

										led2.direction = digitalio.Direction.OUTPUT 

										led3 = digitalio.DigitalInOut(board.D4) 

										led3.direction = digitalio.Direction.OUTPUT 

										led4 = digitalio.DigitalInOut(board.D5) 

										led4.direction = digitalio.Direction.OUTPUT 

										led5 = digitalio.DigitalInOut(board.D6) 

										led5.direction = digitalio.Direction.OUTPUT

PYTHON

In the case of this code, I had to import some libraries: import boar` and import digitalio. These will help us assign the pins and determine if they are inputs or outputs. Import time will allow us to pause the code for a specified amount of time using time.sleep().
Flags will allow the button to detect only one press when it is pushed. The other variables are counters that let us see the state of the game; the state variable indicates whether the main counter starts to increase or decrease.


										#IMPORT LIBRARIES--------------------  

										import board 

										import digitalio 

										import time 

										 

										#VARIABLES-------------------------------- 

										flag1 = 1       #flag for the buttons 

										flag2 = 1 

										

										cont = 0        #main counter to turn on leds 

										cont_vel = 1    #counter to determine speed 

										state = 1       #counter increases(1) or decreases(0) 

										game = 0        #start game 

										cont_red = 0    #count when you reach the color red

PYTHON

Here, we create a start for the game. It is necessary to press both buttons for the game to start. It will send a "Start" message. Then it will perform a sequence of turning all the LEDs on and off.


										while True: 

										#START GAME---------------------------------------- 

										  #press the two buttons to start, small blink and I enter the game loop 

										  if push1.value == True and push2.value == True : 

											  game = 1 

											  print("-----------START-------------") 

											  led1.value = True 

											  led2.value = True 

											  led3.value = True 

											  led4.value = True 

											  led5.value = True 

											  led6.value = True 

											  led7.value = True 

											  led8.value = True 

											  led9.value = True 

											  time.sleep(.05) 

											  led1.value = False 

											  led2.value = False 

											  led3.value = False 

											  led4.value = False 

											  led5.value = False 

											  led6.value = False 

											  led7.value = False 

											  led8.value = False 

											  led9.value = False 

											  time.sleep(.05) 

											  state=1

PYTHON

By pressing both buttons, the 'Game' variable will change to one, and we will enter the game cycle. 'Game Speed' will start at 100, and each time it repeats, it decreases by one. In this way, the internal delay will repeat fewer times, making the game faster
Here, flags are applied so that the code repeats only once and nothing happens if we keep the first button pressed so that the main counter increases, and the second button will cause it to decrease.


										#GAME LOOP---------------------------------  

										while game == 1: 

									 

											#game speed 

											for x in range(0,100-cont_vel): 

												time.sleep(0.001) 

											 

											#first button with flag, counter increases  

											and speed increases 

											if push1.value == True and flag1 == True: 

												state = 1 

												cont_vel = cont_vel + 1 

												flag1 = 0 

											if push1.value == False and flag1 == False: 

												flag1 = 1 

									 

											#second button with flag, counter decreases   

											#and speed increases 

											if push2.value == True and flag2 == True: 

												state = 0 

												cont_vel = cont_vel + 1 

												flag2 = 0 

											if push2.value == False and flag2 == False: 

												flag2 = 1 

									 

											#counter increases or decreases 

											if state == 1: 

												cont = cont + 1 

											if state == 0: 

												cont = cont - 1

PYTHON

For Python, there is no `case` statement, so I had to write the code using the `if` statement, which essentially serves the same purpose.


										#cases for the accountant  

										if cont == 0: 

											#blink and we give up the game 

											for x in range(0,6): 

												led1.value = True 

												led2.value = True 

												led3.value = True 

												led4.value = True 

												led5.value = True 

												led6.value = True 

												led7.value = True 

												led8.value = True 

												led9.value = True 

												time.sleep(.05) 

												led1.value = False 

												led2.value = False 

												led3.value = False 

												led4.value = False 

												led5.value = False 

												led6.value = False 

												led7.value = False 

												led8.value = False 

												led9.value = False 

												time.sleep(.05) 

											game = 2


										#LED1 turns on and network increases 

										if cont == 1: 

											led1.value = True 

											led2.value = False 

											led3.value = False 

											led4.value = False 

											led5.value = False 

											led6.value = False 

											led7.value = False 

											led8.value = False 

											led9.value = False 

											cont_red = cont_red + 1 

								 

										#LED2 turns on and network increases 

										if cont == 2: 

											led1.value = False 

											led2.value = True 

											led3.value = False 

											led4.value = False 

											led5.value = False 

											led6.value = False 

											led7.value = False 

											led8.value = False 

											led9.value = False

PCB MANUFACTURING

design

Here I show the PCB manufacturing process for this practice

PCB

design

For the design of the pcb, I used the fusion 360 program, with its electronic design tool, I began by creating a plan of the size of the pcb and using the plan

design

Find the schematic of the missing components and add them in fusion, also activate more components that the program has

design

I started adding all the components I was going to use like LEDs and resistors. Using the Connect tools, I added names to the connections.

design

With all the components linked, I moved on to the actual display so I could arrange the components into place. Use the alignment tools to accommodate them.

design

I set up the track configuration and used the Autoroute tool to make the connections.

design

To generate the PCB cut images, I typed export in the top bar, image and it gave it a resolution of 2000. I exported one for the tracks and one for the cut

PCB

Tracks
Cut

design

Having the cutting images, use the CNC Drill to manufacture the PCB. For more information visit week four

design

Having the PCB and the components, I started soldering to finish with the PCB.

final result

Loading either of the two codes, we would obtain the same result in terms of the operation of the PCB. Within the program terminals we can see how many times the light bounces and the total points that were obtained.