Sensebender Micro + button

[Pierre P]

Voltage is not good (it's a new 3Vcc button cell) and batterie pourcentage is at 76%

The battery voltage is not just minus 0.3V...

[tbowmo]

@Pierre-P

The measurement method is not accurate at all. It relies on an internal reference that can vary in value between boards (I can't remember the accuracy of it at the moment)

If you don't want the battery voltage, then uncomment the #define for BATT_SENSOR in the top of the sketch, and move the float siVolt = vcc/1000; to be within the #ifdef BATT_SENSOR like:

#ifdef BATT_SENSOR
    float siVolt = vcc / 1000;
    gw.send(msgBatt.set(siVolt, 2));
#endif

Now it should compile, and send battery percentage as the standard sensebender sketch.

[Pierre P]

I personaly think that it's quite good. When powered by FTDI, it found 3.00V.
And I have only add the "//" to BATT_SENSOR and it work good.
(you inverted the thing in the message just above).

Thanks again for you help.
Now i work very good and very fast. I just have to check for adding an antenna to the controller.

[tbowmo]

@Pierre-P

The FTDI probably supplies the board with 3.3V and not 3V..

[alexsh1]

@Pierre-P How do you find the battery life please? I am planning to fit Sensebender with nrf24l01+ SMD and CR2032, but I wonder how long the battery is going to survive? Appreciate if depends on your sketch, but given one is conservative (i.e. no need to send temp/hum every 30-60 sec, but probably every 5-10mins or so), what's your estimate please?

[Pierre P]

I can't tell you for the moment, I haven't check the real voltage of the CR2032 at the beginning. I'll try to make two mesure between 30 days.
But my sketch is 1800000ms or 30min sleeping (if no-one press the button). Because it's a redundant information, my Jeedom controler have a meteo plugin who's working good. (i'll use it for the mini-night-temperature to have a message if there is glass on my car's windows).

[iotcrazy]

@Pierre-P you controller image looks great . What controller is it ?

[Pierre P]

@iotcrazy It is Jeedom, you can find some information here: http://www.mysensors.org/controller/jeedom
It use an RPI2 if you ant to make it yourself, and a major version will come during the week !

[alexsh1]

@martinhjelmare Any idea why siVolt is reporting values rounding up to either 2V or 3V in Domoticz? All I'd like to have is something like 2.9V

[martinhjelmare]

@alexsh1

How are you calculating and sending it? Did you change to float? There was a bug in my original sketch.

Make sure at least one of the operands is a float in the division.

float siVolt = vcc / 1000.0;

[alexsh1]

@martinhjelmare

Yes, it is declared as float

void sendBattLevel(bool force)
{
  if (force) lastBattery = -1;
  long vcc = readVcc();
  if (vcc != lastBattery) {
    lastBattery = vcc;
  float siVolt = vcc / 1000;
#ifdef BATT_SENSOR
    gw.send(msgBatt.set(siVolt, 2));
#endif

It is reported as either 2.000V (battery) or 3.000V (USB) in Domoticz
Changing siVolt to int or changing 2 in set does not change anything.

[martinhjelmare]

@alexsh1 said:

float siVolt = vcc / 1000;

You should change 1000 to 1000.0, i.e. a float. Float math will be used if any of the operands is a float.
https://www.arduino.cc/en/Reference/Arithmetic

[alexsh1]

@martinhjelmare Stupid me! Thanks for bringing this up - these issues are so simple, but very easy to overlook. I was about to start pulling my hair out....