ESP8266 Community Forum

- Fri Aug 19, 2016 9:21 pm #53332 I know its sounds strange , I have added volt meter parallel to the esp vcc and ground to see the voltage consumption as below :



Now when first time the esp wake up i see on the voltage meter 3.4V

After couple of cycles (2-4) of deep sleep and wake up i see the voltage drops down to 2.2V,
In this step the esp stops working (no data transmission) .

Now if i short the capacitor legs the voltage comes back to 3.4V


What is wrong , please help ?

Last edited by stavbodik on Sat Aug 20, 2016 9:44 am, edited 2 times in total.

- Fri Aug 19, 2016 10:40 pm #53333 Do you have a "supercap" capacitor across VCC? If so then what you are seeing is normal from my experience. They are a what I call spongy, with a fair amount of hysteresis. The ones I have used for clock circuits are able to hold a lot of energy but they don't charge or release it very quickly.


EDIT:

You have caused a lot of confusion by the question you asked (capacitor discharge) and not stating that you had a regulator supplying providing constant supply to the circuit. (I see you have now included it in the schematic and earlier posts) If you had been clear on this you would have had your question answered much sooner. You are not using an appropriate regulator for that application.

Last edited by rudy on Sat Aug 20, 2016 7:16 pm, edited 2 times in total.

- Sat Aug 20, 2016 12:06 am #53335

Do you have a "supercap" capacitor across VCC? If so then what you are seeing is normal from my experience. They are a what I call spongy, with a fair amount of hysteresis. The ones I have used for clock circuits are able to hold a lot of energy but they don't charge or release it very quickly.

No i have only the 104, what i have noticed is that if i short the LDO which i am using right now vin and vout
I get same behavior maybe one of the LDO capacitors is Supercap ?

The one i am using is AMS1117 with LED light on it :



Couldn't find anywhere data sheet of it to find out about his capacitors, maybe some one knows ?
By the way i run now already for 2 hours w/o problems .

- Sat Aug 20, 2016 2:25 am #53339 forgot to switch off the "hold" function of your voltmeter?