Help! I am using a AHT20+BMP280 sensor with ESP8266 or ESP32 controllers with OLED screen. I can display everything correctly on the OLED - Temperature, Humidity, and Barometric Pressure. The problem I am having is I want to add a Highest/Lowest temperature, pressure, humidity readout on the fourth line. I have managed to get it to work with High/Low temperature readings so far. My problem arises when trying to assign the Barometric Pressure reading to a variable to keep track of the High/Low. I get 'nan' which I believe stands for "not a number"??? I think this may have something to do with the output being a 32 but unsigned integer???
Sloppy code below - I have tried many things. How do I turn that 32 bit integer into a decimal number I can store in a variable??? Any help???
#include <Adafruit_AHTX0.h>
#include <SPI.h>
#include <Adafruit_BMP280.h>
Adafruit_AHTX0 aht;
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
#define BMP_SCK (13)
#define BMP_MISO (12)
#define BMP_MOSI (11)
#define BMP_CS (10)
Adafruit_BMP280 bmp; // I2C
//Adafruit_BMP280 bmp(BMP_CS); // hardware SPI
//Adafruit_BMP280 bmp(BMP_CS, BMP_MOSI, BMP_MISO, BMP_SCK);
// #define I2C_SDA 06
// #define I2C_SCL 05
// Define pins for mini? Didn't work?
//HiLo Variables
float HI_TEMP = 0;
float LO_TEMP = 0;
int COUNTER = 0;
uint32_t BP_READING = 0;
uint32_t HI_BP = 0;
uint32_t LO_BP = 0;
float HI_HUM = 0;
float LO_HUM = 0;
void setup() {
Serial.begin(115200);
Serial.println("Adafruit AHT10/AHT20 demo!");
if (! aht.begin()) {
Serial.println("Could not find AHT? Check wiring");
while (1) delay(100);
}
Serial.println("AHT10 or AHT20 found");
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
delay(2000); // Pause for 2 seconds
// Clear the buffer.
display.clearDisplay();
testscrolltext();
// Clear the buffer.
//display.setRotation(2);
//Rotate Display???
display.clearDisplay();
display.setTextSize(2);
display.print(" HELLO!");
display.display();
delay(1000);
while ( !Serial ) delay(1000); // wait for native usb
Serial.println(F("BMP280 test"));
unsigned status;
//status = bmp.begin(BMP280_ADDRESS_ALT, BMP280_CHIPID);
status = bmp.begin();
if (!status) {
Serial.println(F("Could not find a valid BMP280 sensor, check wiring or "
"try a different address!"));
Serial.print("SensorID was: 0x"); Serial.println(bmp.sensorID(),16);
Serial.print(" ID of 0xFF probably means a bad address, a BMP 180 or BMP 085\n");
Serial.print(" ID of 0x56-0x58 represents a BMP 280,\n");
Serial.print(" ID of 0x60 represents a BME 280.\n");
Serial.print(" ID of 0x61 represents a BME 680.\n");
while (1) delay(10);
}
/* Default settings from datasheet. */
bmp.setSampling(Adafruit_BMP280::MODE_NORMAL, /* Operating Mode. */
Adafruit_BMP280::SAMPLING_X2, /* Temp. oversampling */
Adafruit_BMP280::SAMPLING_X16, /* Pressure oversampling */
Adafruit_BMP280::FILTER_X16, /* Filtering. */
Adafruit_BMP280::STANDBY_MS_500); /* Standby time. */
}
void testscrolltext(void) {
display.clearDisplay(); // clear the display screen of the OLED
display.setTextSize(3); // Draw 2X-scale text
display.setTextColor(WHITE);
display.setCursor(0, 0);
//display.println(F("Welcome"));
delay(2000);
display.clearDisplay();
sensors_event_t humidity, temp;
aht.getEvent(&humidity, &temp);
HI_TEMP = ((temp.temperature*9/5)+32);
LO_TEMP = ((temp.temperature*9/5)+32);
BP_READING = bmp.readPressure()/3386;
delay(100);
HI_BP = bmp.readPressure()/3386;
delay(100);
LO_BP = bmp.readPressure()/3386;
delay(100);
BP_READING = bmp.readPressure()/3386;
Serial.println(F("BP_READING= "));
Serial.println(BP_READING);
Serial.println(HI_TEMP);
Serial.println(LO_TEMP);
Serial.println(HI_BP);
Serial.println(LO_BP);
Serial.println(BP_READING);
}
void loop() {
COUNTER = COUNTER + 1;
if (COUNTER > 40) {
COUNTER = 0;
}
display.clearDisplay();
display.setCursor(0, 0);
sensors_event_t humidity, temp;
aht.getEvent(&humidity, &temp);// populate temp and humidity objects with fresh data
display.print((temp.temperature*9/5)+32); display.println(" F");
if (((temp.temperature*9/5)+32) > HI_TEMP) {
HI_TEMP = ((temp.temperature*9/5)+32);
}
if (((temp.temperature*9/5)+32) < LO_TEMP) {
LO_TEMP = ((temp.temperature*9/5)+32);
}
display.print(humidity.relative_humidity); display.println(" %");
display.print((bmp.readPressure()/3386)); display.println(" inHg");
BP_READING = bmp.readPressure()/3386;
Serial.print(F("BP_READING= "));
Serial.println(BP_READING);
//Assign new values if they are HI or LO
if (BP_READING > HI_BP) {
HI_BP = BP_READING;
}
if (BP_READING < LO_BP) {
LO_BP = BP_READING;
}
//Display HI/LOs based on counter
if (COUNTER < 21) {
display.print(HI_TEMP); display.print(" F HI");
}
if (COUNTER > 20 && COUNTER < 41) {
display.print(LO_TEMP); display.print(" F LO");
}
// if (COUNTER > 20 && COUNTER < 31) {
// display.print(HI_BP); display.print(" BP HI");
// }
// if (COUNTER > 30 && COUNTER < 41) {
// display.print(LO_BP); display.print(" BP LO");
// }
display.display();
//Serial Print for debugging
Serial.print(F("Temperature = "));
Serial.print((bmp.readTemperature()*9/5)+32);
Serial.println(" *F");
Serial.print(F("Pressure = "));
Serial.print(bmp.readPressure());
Serial.println(" Pa");
Serial.print(F("Barometric Pressure = "));
Serial.print((bmp.readPressure()/3386));
Serial.println(" inHg");
Serial.println(HI_TEMP);
Serial.println(LO_TEMP);
Serial.println(HI_BP);
Serial.println(LO_BP);
Serial.println(BP_READING);
Serial.println();
delay(1000);
}
