I am trying to find a way to make the battery last longer. I am using the P1 module with 4 AA on a 6V system. The wifi is turn off. I just let the system run and the system last about 3 days. From the p1 datasheet, the operating current is about 30mA-40mA that seem to be right with my test.
Operating Current (Wi-Fi off) I3V3 avg[1] 30 40 mA
Unfortunately, the system can’t not enter a deep sleep mode. Is there anyway to lower the current consumption? What other options could I try? The p1 need to keep track of a sensor when there is activity.
You’d need to give some more detail about your setup.
e.g. what kind of sensor are you talking of?
Could the sensor wake the device from Stop or Standby Mode via an interrupt pin?
@ScruffR, I am using a HTU21D sensor, 2.4" spi tft lcd, P1 and a relay. The basic setup is to have the user set the temperature, once the HTU21D temperature reach the user set temperature, P1 will trigger the relay. Wifi will be off while using battery since, it drain to much current. Ideally if the battery could last 2-3 month it would be great. I was thinking having the device sleep for a set amount of time then wake and sample the temperature. If I can get the current draw down to average of 1-2mA that will give me the time I am looking for since AA Capacity is around 2250mah. Any other Ideas will be great. Thanks
So given that, why could your device not deep sleep during that time?
Or should the P1 permanently drive the display?
In that case, I'd say the display will be the power hog.
@ScruffR, at first I was thinking to keep the display on all the time but as you said it will be a power hog. The battery will not last. What do you suggest? Is it possible to have an average current at 1ma-2ma or lower? I am thinking if I could disable the cloud and wifi at startup and run it as a purely MCU, this would save some battery life and use deep sleep cycle. Is it possible to play around with the clock speed? At the end of the day, I am trying to achieve 2-3 month with 4 AA. Any guidance would be great, I am a bit confuse at this point. Thanks
You could use ePaper/eInk display which will only use power while updating and then just hold the contents without further power draw.
With that and long enough deep sleep phases you can extend the battery life considerably.
@ScruffR, ePaper/eInk is great but the production cost will be out of the budget range. The only option is the deep sleep route. Just need to put together a test case and see what result it gives.