flipper-zero-tutorials/js/adc/ai-sensor.js
2024-06-14 20:57:47 -05:00

72 lines
2.4 KiB
JavaScript

// Script created by ChatGPT 4
// @CodeAllNight / MrDerekJamison
// Discord server - https://discord.com/invite/NsjCvqwPAd
// Github - https://github.com/jamisonderek/flipper-zero-tutorials
// Flipper Zero JavaScript ADC (Analog-to-Digital Converter) demo.
// Required hardware connections...
// Step 1. Connect a NTC Thermistor (R0:2K, B:3470K) to 3.3V and Pin A7.
// Step 2. Connect a 2.2K Resistor to Pin A7 and GND.
// Requires MNTM-005 (or current Momentum dev build)
let gpio = require("gpio");
let Math = require("math");
// Constants for the thermistor calculation
let B = 3470; // B value of the thermistor
let R0 = 2000; // Resistance of the thermistor at T0 (in ohms)
let T0 = 298.15; // Reference temperature (25°C in Kelvin)
let Vref = 3.3; // Reference voltage in volts
// Initialize pin A7 as analog
gpio.init("PA7", "analog", "no");
// Start analog reading with a reference voltage of 3.3V
gpio.startAnalog(2048); // vRef = 2.048V (scaled)
function readTemperature() {
let millivolts = gpio.readAnalog("PA7");
// Voltage divider calculation
let R1 = 2200; // Known resistor value in ohms (2.2kΩ)
let Vout = millivolts / 1000; // Convert millivolts to volts
if (Vout === 0) {
return 0;
}
let Rt = R1 * (Vref / Vout - 1); // Corrected thermistor resistance calculation
// Steinhart-Hart equation to calculate temperature in Kelvin
let logRt = Math.log(Rt / R0);
let invT = (1 / T0) + (1 / B) * logRt;
let tempK = 1 / invT;
let tempC = tempK - 273.15; // Convert Kelvin to Celsius
let tempF = tempC * 9 / 5 + 32; // Convert Celsius to Fahrenheit
return tempF;
}
function formatTemperature(temp) {
let roundedTemp = Math.floor(temp * 100 + 0.5) / 100; // Round to two decimal places
let intPart = Math.floor(roundedTemp); // Integer part
let fracPart = Math.floor((roundedTemp - intPart) * 100); // Fractional part
let intPartStr = to_string(intPart);
let fracPartStr = fracPart < 10 ? '0' + to_string(fracPart) : to_string(fracPart); // Ensure two digits in the fractional part
return intPartStr + '.' + fracPartStr;
}
// Main loop to read and display the temperature every second
while (true) {
let tempF = readTemperature();
if (tempF !== 0) { // Ignore invalid measurements
print("Temperature: " + formatTemperature(tempF) + " F"); // Use " F" instead of "°F"
}
delay(1000); // Wait for 1 second
}
gpio.stopAnalog();