Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

User avatar
By trackerj
#31886
eduperez wrote:
gregware wrote:The battery voltage seems to drop rather quickly, does this indicate that the battery drains out?
Would be interesting to find out how long this can last on a '2000mAh' battery?

Thanks for the posting!

Greg


I think the scale on that graph can lead to the wrong conclusion: even if the voltage has barely moved, it appears as a big drop, because the lower part of the graph is not at 0v.


Used the "zoom" scale to be able to see better the small voltage variations. With graph origin at 0V it will look line a line, not too much usable visual information.

battery_voltage_run_full_0.jpg


How is looking so far,in a more user friendly view:

battery_voltage_run_1.jpg
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User avatar
By Vincent Lê
#31890 Hi,

It's uncommon, but I try to "up" my post as it has been overtaken by a 5-6 messages flow.

Hi,

I have read your posts with a great attention since I am working on a coin cells based project.

My project will run on two CR2032 during 1 year and some months, using deep sleep mode.

As the deepsleep current is still arount 30uA, your RTC solution would extend my barrety life to 4 years !

Now I have one question: how do your circuit shut down?

I understand that the RTC will trigger the power source as its alarm will be ringed. at the end of the operations (say after 3s), what causes the power shut down of the ESP?
User avatar
By Barnabybear
#31891
Vincent Lê wrote:Hi,

It's uncommon, but I try to "up" my post as it has been overtaken by a 5-6 messages flow.


Hi, have a look at this post its probably more relevant to your application as you may not need a voltage regulator http://www.esp8266.com/viewtopic.php?f=11&t=4458
Feel free to reply on that post if you have any questions.
User avatar
By DrG
#31959
Vincent Lê wrote:Hi,

I have read your posts with a great attention since I am working on a coin cells based project.

My project will run on two CR2032 during 1 year and some months, using deep sleep mode.

As the deepsleep current is still arount 30uA, your RTC solution would extend my barrety life to 4 years !

Now I have one question: how do your circuit shut down?

I understand that the RTC will trigger the power source as its alarm will be ringed. at the end of the operations (say after 3s), what causes the power shut down of the ESP?



The power is shut down by resetting the RTC interrupt flag in sofware. This is the last function of the ESP8266 code - to disconnect itself and all power....until the next time the RTC wakes up the unit.

The actual code is:
// Reset interrupt flag IF for alarm #1
void resetIF1(){
byte status;

Wire.beginTransmission(0x6f);
Wire.write(0x0d);
Wire.endTransmission();
Wire.requestFrom(0x6f,1);
status=Wire.read();
status=status & 0xf7;
Wire.beginTransmission(0x6f);
Wire.write(0x0d);
Wire.write(status);
Wire.endTransmission();
}

BTW: The project is continuing on and I recently moved the circuit from the breadboard to a prototype see below).
Image

I changed R1 to 4.7K and added some pins for easy I2C access, terminals for battery and regulated output and a shorting block jumper for testing. Now, I am moving on to the software. So far, still so good...I wish I had more time to devote to these projects but that is not the case at the present.

Cheers,
DrG