Arduino uno User Manual

void setup() {
10
Serial.begin(BAUD_RATE);
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}
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void loop() {
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unsigned long current_millis = millis();
15
if (abs(current_millis - last_measurement) >= 1000) {
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current_temperature = get_temperature();
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last_measurement = current_millis;
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}
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Serial.print(scaled_value(current_temperature));
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Serial.print(",");
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const unsigned long duration = measure_distance();
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Serial.println(scaled_value(microseconds_to_cm(duration)));
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}
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25
long scaled_value(const float value) {
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float round_offset = value < 0 ? -0.5 : 0.5;
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return (long)(value * 100 + round_offset);
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}
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30
const float get_temperature() {
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const int sensor_voltage = analogRead(TEMP_SENSOR_PIN);
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const float voltage = sensor_voltage * SUPPLY_VOLTAGE / 1024;
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return (voltage * 1000 - 500) / 10;
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}
35
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const float microseconds_per_cm() {
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return 1 / ((331.5 + (0.6 * current_temperature)) / 10000);
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}
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40
const float sensor_offset() {
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return SENSOR_GAP * microseconds_per_cm() * 2;
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}
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const float microseconds_to_cm(const unsigned long microseconds) {
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const float net_distance = max(0, microseconds - sensor_offset());
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return net_distance / microseconds_per_cm() / 2;
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}
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const unsigned long measure_distance() {
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pinMode(PING_SENSOR_IO_PIN, OUTPUT);
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digitalWrite(PING_SENSOR_IO_PIN, LOW);
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delayMicroseconds(2);
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digitalWrite(PING_SENSOR_IO_PIN, HIGH);
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delayMicroseconds(5);
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digitalWrite(PING_SENSOR_IO_PIN, LOW);
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pinMode(PING_SENSOR_IO_PIN, INPUT);
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return pulseIn(PING_SENSOR_IO_PIN, HIGH);
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}
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Increasing Precision Using a Temperature Sensor • 91
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Arduino uno Specifications

General

Form factor	Arduino
Certification	RoHS, FC, CE
Processor model	-
Processor frequency	- MHz
Microcontroller model	ATmega328
Microcontroller frequency	16 MHz
DC input voltage	7-12 V
Operating voltage	5 V
DC current per I/O pin	40 mA
Flash memory	0.032 MB
Maximum internal memory	- GB
SRAM (Static Random Access Memory)	2 KB
EEPROM (Electrically Erasable Programmable Read-Only Memory)	1 KB
Wi-Fi	No
Number of analog I/O pins	6
Number of digital I/O pins	14

Weight and Dimensions

Board dimensions	53.4 x 68.6 mm