Keyestudio ESP32 - Page 151

ESP32 Starter Kit
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float checkdistance() { //Acquire distance
// preserve a short low level to ensure a clear high pulse:
digitalWrite(TrigPin, LOW);
delayMicroseconds(2);
// Trigger the sensor by a high pulse of 10um or longer
digitalWrite(TrigPin, HIGH);
delayMicroseconds(10);
digitalWrite(TrigPin, LOW);
// Read the signal from the sensor: a high level pulse
//Duration is detected from the point sending "ping" command to the time receiving␣
˓→echo signal (unit: um).
float distance = pulseIn(EchoPin, HIGH) / 58.00; //Convert into distance
delay(10);
return distance;
}
LedControl lc = LedControl(DIN, CLK, CS, 4);
byte data_val[4][8] = {
{ 0x00, 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x00 },
{ 0x00, 0x00, 0x04, 0x05, 0x05, 0x04, 0x00, 0x00 },
{ 0x00, 0x10, 0x14, 0x15, 0x15, 0x14, 0x10, 0x00 },
{ 0x40, 0x50, 0x54, 0x55, 0x55, 0x54, 0x50, 0x40 },
};
void setup() {
lc.shutdown(0, false); //MAX72XX is in power-saving mode at startup
lc.setIntensity(0, 8); //Set the brightness to its maximum value
lc.clearDisplay(0); //Clear display
pinMode(TrigPin, OUTPUT); //Set Trig pin to output
pinMode(EchoPin, INPUT); //Set Echo pin to input
Serial.begin(9600);
}
void loop() {
distance = checkdistance();
Serial.println(distance);
if (distance < 15) {
temp = 0;
} else if (distance < 30 && distance > 15) {
temp = 1;
} else if (distance < 40 && distance > 30) {
temp = 2;
} else if (distance > 50) {
temp = 3;
}
for (int i = 0; i < 8; i++) {
lc.setRow(0, i, data_val[temp][i]);
}
}
8.5. Arduino Project 147