Embedded Programming

As an architect, I had not programmed anything until now. My first approach to programming was in week 4 when I programmed the Quentorres so that the LED turned on. Therefore, this week's assignment seemed like a great challenge for me.

First of all, I did my first programming tests with the XIAO RP2040, a LED and a button connected on a breadboard. I did this because I was afraid of damaging some PCB components that were so difficult to find in my country. After gaining confidence, I programmed the microcontroller in the Quentorres PCB so after pressing the button the LED would light up 8 times and send a message to the Arduino IDE serial monitor. For accomplish this, I used this guide and help from my colleague Ronal Vilca. I used this code in Arduino IDE:

const int ledPin = D6;     // the number of the LED pin
const int buttonPin = D1;  // the number of the pushbutton pin
int buttonState = 0;       // variable for reading the pushbutton status

void setup()
{
  Serial.begin(9600);
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);

}  
void loop()
{
  buttonState = digitalRead(buttonPin);	
  if (buttonState == HIGH) {
  for (int i=0; i<=7; i++)
  {
	delay(500);
	digitalWrite(ledPin, HIGH);
	delay(1000);
	digitalWrite(ledPin, LOW);
	
  }
} else {

  digitalWrite(ledPin, LOW);
}

}

Code being upload to XIAO RP2040 for programming button and LED in Quentorres

Data send to the serial monitor from the button on Quentorres once it is pressed

I felt very happy and motivated when the code worked. So I decided to program a soil moisture sensor based on this code. Every 10 seconds the measured humidity percentage of a pot with soil and a lemon tree would appear on the Arduino IDE serial monitor. After breaking a component of the Quentorres (because it was desoldered), adjusting loose wires, and several tests, the programming worked. I used this code in Arduino IDE:

// constants
const int hygrometer = A2;  // hygrometer sensor analog pin output at pin A2 of XIAO RP2040
// variables									
int value;
											
void setup(){

  Serial.begin(9600);
}

void loop(){
  // when the plant is watered well the sensor will read a value 380∼400, I will keep the 400
  // value but if you want you can change it below.

  value = analogRead(hygrometer);     // read analog value
  value = constrain(value,400,1023);  // keep the ranges
  value = map(value,400,1023,100,0);  // map value: 400 will be 100 and 1023 will be 0
  Serial.print("Soil humidity: ");
  Serial.print(value);
  Serial.println("%");
  delay(10000);                       // read every 10 seconds
}

Code in Arduino IDE for programming the hygrometer in Quentorres

Code of hygrometer well programmed