ESP8266 Community Forum

- Tue May 19, 2015 5:39 pm #17905 Ran more tests and I can confirm that my ESP-01 is working down to 2.2V. In the long term it mightn't be very stable but it is working.

The serial flash memory chip used on my board is a 25Q40BV. I couldn't find an exact datasheet for this part but similar parts from winbond operate from as low as 1.65V and the closest I could find was the W25Q40CL which has an operating voltage of 2.3 to 3.6V. Below is a link to the data.

https://www.winbond.com/hq/product/code ... o=W25Q40CL

It looks like the memory used on your module (ESP-12) does not have the same supply voltage range.

- Tue May 19, 2015 9:21 pm #17914 Thanks for following up and providing that data. Yes, many versions of memory can operate at low Vcc, it just depends on which version. Now I'll have to pop a top off of my ESP-12 modules and see what's there. It still bothers me that you are able to operate at 2.2V though since the datasheet for the ESP8266 says that it's a 3.3V part and I've never run across a 3.3V part that could operate with that low of a voltage. I know that the IO on the ESP8266 can be operated at 1.8V but none of the modules I've seen have regulators to generate that 1.8V and if they did you wouldn't be able to interface to 3.3V on the GPIO pins.

The mystery continues...

- Wed May 20, 2015 3:25 am #17933

Not sure if it matters (or maybe it really does) but I'm running NodeMCU (NodeMCU 0.9.5 build 20150318 powered by Lua 5.1.4).

Moin,

I get a smell that this maybe related to the "zombie" mode issue discussed in the big "zombie mode" thread.
To make it short:
Waking up from deep sleep (and maybe sometimes on reset? Don't know about power up) modules
got stuck.
I was able to reproduce the problem and they all vanished for me when using an nodemcu
using some SDK 1.x libs.
The thread has a link in one of the last posts to a git repo with an SDK 1.x based nodemcu.
You may give that a test.

I saw that you already posted in that thread so you may already know ...

Cal

Get your modules here:

https://www.banggood.com/custlink/KvGGhGF4wG

- Wed May 20, 2015 8:09 am #17953 Hi Cal:

Thanks, yes I was reading through that thread and wondered myself, especially since sometimes on power up during my testing I can see the module pull ~400mA. I'll find that link later this morning and give that firmware a try. I don't have the SDK installed or the toolchain as I was hoping I didn't have to go through all of that for my initial testing.

You're talking about thislink, https://github.com/chadouming/nodemcu-firmware, right?

George