I’ve currently a problem reading my BME280 sensor: Sometimes, randomly the sensor starts to send “wrong” values, f.e -140 degrees for temperature. If I press the Reset button my photon, it doesnt solve the issue. Only if I un- and replug the power connection, it’s working again… Does anybody else has this problem? If yes, how did you solve it?
My idea was to reinitiate the sensor if the temperature falls below -50 degress (which will never happen normally in my region xD). I’m using the Adafruit BME280 library. How can I reinitiate the sensor properly?
How is connected power to the BMP280? 3v3?
I’ve got the same issue, the only way to solve it was to power the sensor by a pin and powercycle it every time.
I have a few BME280s and have not run into that problem in the few years they’ve been running. They on Photons, connected by I2C with 10K pull-ups. They’re on a custom circuit board, so the traces are short. There’s also a 0.1uF capacitor on the BME280 3V3 connection, right next to the chip. I’d guess you have a power issue that is causing the sensor to crash, essentially, and not respond to I2C/SPI.
I don’t use any resistors with I2C. Do you mean a power issue in the meaning of a bad connection (soldering) or that the particle doesnt provide enough power for the sensor?
@electronweather, I had similar issues with a Photon that wakes, takes a reading and goes to deep sleep. Because of the low power consumption of the BME280, I ended up powering it via a GPIO pin so it gets powered off in deep sleep. Doing this, I haven’t had ANY reading reliability issues. I use the Adafruit_BME280 library and power up the BME280 and delay 50ms before calling begin() for the device.
So there isn’t any possibility to restart the sensor only by software? I’ve tried it with pressing the RESET button (AFAIK this forces the Photon to restart =re-do the Setup process where bme.begin(); is called but it only works with “hardreset” (unplug power source)
@electronweather, here is my code (minus the Blynk stuff I use):
/***************************************************************************
This is a library for the BME280 humidity, temperature & pressure sensor
Designed specifically to work with the Adafruit BME280 Breakout
----> http://www.adafruit.com/products/2650
These sensors use I2C or SPI to communicate, 2 or 4 pins are required
to interface.
Adafruit invests time and resources providing this open source code,
please support Adafruit andopen-source hardware by purchasing products
from Adafruit!
Written by Limor Fried & Kevin Townsend for Adafruit Industries.
BSD license, all text above must be included in any redistribution
This file was modified by Markus Haack (https://github.com/mhaack)
in order to work with Particle Photon & Core.
***************************************************************************/
#include <Adafruit_BME280.h>
SYSTEM_THREAD(ENABLED);
void startRGB() {
RGB.control(true);
RGB.color(0,0,0);
}
STARTUP( startRGB() );
#define BME_SCK D4
#define BME_MISO D3
#define BME_MOSI D2
#define BME_CS D5
#define BME_PWR D3
#define SEALEVELPRESSURE_HPA (1013.25)
Adafruit_BME280 bme; // I2C
//Adafruit_BME280 bme(BME_CS); // hardware SPI
//Adafruit_BME280 bme(BME_CS, BME_MOSI, BME_MISO, BME_SCK);
double temperature, pressure, altitude, humidity;
char buff[100];
unsigned long wait;
void setup() {
bool BMEstarted = false;
Serial.begin(9600);
// If WiFi takes more than 10secs to reconnect, reset and try again
if (!waitFor(Particle.connected, 10*1000))
System.reset();
// Power ON the BME280 board
pinMode(BME_PWR, OUTPUT);
digitalWrite(BME_PWR, HIGH);
delay(50);
do {
if (!bme.begin()) {
// Cycle power on BME280 board to reset it and try to initialize it again
digitalWrite(BME_PWR, LOW);
delay(50);
digitalWrite(BME_PWR, HIGH);
}
else
BMEstarted = true;
} while (!BMEstarted);
wait = millis();
}
void loop() {
// Update data from BME80
updateData();
while (millis() - wait < 5U*1000U) { // flush data from Blynk and TCP for 5 secs
Particle.process();
}
System.sleep(SLEEP_MODE_DEEP, 30*60);
}
void updateData() {
temperature = bme.readTemperature();
pressure = bme.readPressure() / 100.0F;
altitude = bme.readAltitude(SEALEVELPRESSURE_HPA);
humidity = bme.readHumidity();
sprintf(buff,"{\"temperature\":%.2f,\"pressure\":%.0f,\"altitude\":%.2f,\"humidity\":%.2f}",temperature, pressure, altitude, humidity);
Particle.publish("BME280", buff, 60, PRIVATE);
//Serial.println(buff);
}
I’m having the same issue but rewiring our setup to use a GPIO for power is (almost) impossible.
Anyone who actually knows what the underlying problem is? Is it a power issue?
We use the DFrobot version of the BME280 sensor but with the library of Adafruit.
Maybe it’s something in their library?
I was never able to find a software-only solution either. It seems the sensor stops responding on the I2C bus and will only work again after its power is cycled.
We’ve had this problem for almost a year and a half. We typically see that the sensor crashes (the Adafruit does a NaN check in order to check if the sensor crashed). We’ve talked with another company who had same issue, they “hotfix” it by sending the configuration again in order to make it work. However, we’ve been unsuccessful at using BME280 in a robust setup, so we’re switching to standalone sensors for humidity, pressure and temperature with more accuracy.
I’m following this thread in order to finally be able to pinpoint the fault and sleep at night.
