ESP8266 Community Forum

- Fri Jul 20, 2018 5:57 pm #77287 Hi all - new to the forum, I have signed up to ask about why the hell 4 different ESP8266 boards have such wildy different standby current.

Some background - I have developed a wood moisture content logger for measuring and report wood moisture content. The idea is that it runs off a small battery and gets built into a building, structure or whatever to monitor if wood remains dry in critical locations.

The circuit uses:

ESP8266
A resistor voltage divider
A transistor

I plan to run it on a single 18650 and a HT7333 voltage regulator.

Currently I am test benching and have 4 units constructed using the same components and wired up in the same way. Two of them have been flashed with what I gather is the latest firmware and two are as supplied.

I am using 1x 12E, 1x12F and 2x 12S.

The 12E and one of the 12Ss have been reflashed. The other 12S and the 12F are as shipped.

I have uploaded the same code onto them and am running them of the 3.3v rail (verified as 3.4v) of a PC power supply. I am monitoring in usage current consumption and am finding all run at 70-80mA when connected to WIFI and taking a measurement. In deepsleep the power usage varies HUGELY between the different boards.

Standby current is as follows:

12E - 200uA
12F - 20uA
12S (reflash) - 960uA
12S (stock) - 1000mA

I am super happy with 20uA. I am sure the HT7333 will add a few uA when they are wired in and the units are running from a battery. But still at that current drawing with 1 measurement a day I should get 12 to 18 months from a 2000mAh 18650.

The others are not great! 1mA is rubbish and even 200uA is way too high.

Does anyone have any ideas as to why there is such wild variation between units? AFAIK the 12E 12F and 12S are supposed to be the same units. Has anyone had similar experiences?

Thanks in advance!
Lewis

- Tue Oct 23, 2018 3:32 pm #78829 Bump - Has anyone got any thoughts?

Are these different current draws a result of the different 'types' of board (i.e. E, F or S) or something else.

I am using them for long-term imbedded sensors in buildings and want to get 2+ years out of them. The 12F will do that and I currently have it running off a 4000mah LiIon (well 2 18650s in parallel) using a HT7333 voltage regulator and it draws 20uA in deepsleep.

I want to build some more and am looking to purchase around 100 units. I will try and order the Fs as so far my experience is that these appear to draw the least current in deepsleep BUT is this true or am I going to find out the hard way that there is something else going on?

Cheers

Lewis

- Tue Oct 23, 2018 6:39 pm #78832 Have you looked if they have the same flash chip?

- Wed Oct 24, 2018 2:28 am #78835 Without reflashing - so to say without knowing what the module does - spraking about “deep sleep“ is theoretical.
Show your setup and code, then we - maybee - can see further.