How is your experience with the accuracy of the bme280 in the MotionMote R3?
I am asking because It is covered from the moteino and everything is in a box.
Do you really measureally the room temperature and humidity?
I have a MotionMote R3 in testing for a few weeks with a Panasonic PIR, and it includes the BME280. The readings are very stable, no issues.
The moteino is on top of it at around 1/2" (1.5cm) and there is a vent cutout in all the MotionMote casings so air can freely flow in/out.
It's very accurate from what I can tell. And actually it's very much in agreement with the Si7021.
And of course everything is really low power.
Are there somewhere the electric circuit files available for the R3?
Additionally:
Why do not you measure the battery voltage with the internal function?
e.g.
unsigned long getVCC(void) {
unsigned long result;
byte saveADMUX;
byte saveADCSRA;
byte saveADCSRB;
saveADMUX = ADMUX;
saveADCSRA = ADCSRA;
saveADCSRB = ADCSRB;
// Read 1.1V reference against AVcc
// set the reference to Vcc and the measurement to the internal 1.1V reference
// REFS1 REFS0 --> 0 1, AVcc internal reference -Selects AVcc external reference
// MUX3 MUX2 MUX1 MUX0 --> 1110 1.1V (VBG) -Wählt den Kanal 14, um die Bandgap-Spannung zu messen
ADMUX = (1<<REFS0) | (1<<MUX3) | (1<<MUX2) | (1<<MUX1);
ADCSRA = (1<<ADEN) | (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);
ADCSRB=0;
TIMING::delay(20); // Wait for Vref to settle
//first measurement is most of the time slightly wrong
ADCSRA |= (1<<ADSC);
while(ADCSRA & (1<<ADSC)); //measuring
TIMING::delay(50); // Wait for Vref to settle
ADCSRA |= (1<<ADSC);
while(ADCSRA & (1<<ADSC)); //measuring
uint8_t low = ADCL; // must read ADCL first - it then locks ADCH
uint8_t high = ADCH; // unlocks both
result = (high<<8) | low;
result = 1125300L / result; // Calculate Vcc (in mV); 1125300 = 1.1*1023*1000 (because...= 3300*1023/3 since 1.1 is exactly 1/3 of 3.3V)
ADMUX = saveADMUX;
ADCSRA = saveADCSRA;
ADCSRB = saveADCSRB;
return result;
}
I guess not yet, I have to put it up on the MMote page.
The BME280 max input voltage is 3.6v so on the MotionMote it takes regulated 3.3v from the Moteino.
DS here: https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280_DS001-11.pdf