ESP8266 Community Forum

- Sun Apr 05, 2015 9:47 am #13561

Hi all,

So I bought a bunch of different modules. Have experimented with only the ESP-01's for now, as I am waiting for adapter boards for the ESP-03, 07 etc..

I really find them quite flakey. I have using a 3.3v source from a quality bench supply, so its not my power source. I have been using an ESP-01 and NodeMCU, with CH_PD high, GPIO0, GPIO2 and RST unconnected (floating). GND is also connected to a FTDI UART. In a temperate measuring module, I had GPIO0 picking up the DHT11 signal.

I am able to flash NodeMCU most of the time, but sometimes it just reboots, or crashes and refuses to come back. I am using the latest NodeMCU firmware.

It sounds like there's some problem with your flashing setup. Do you ever get errors while flashing?

I initially had flashing errors, but they were due to my handrolled MAX232 RS232 to TTL adaptor - I had missed one connection. Once I fixed that, my flashes were always successful. And I have to say that my ESP-01s have been surprisingly rock-solid from a hardware standpoint. Of course, if I screw up the firmware, it's not happy

I have a few ESP-07s and ESP-12s but haven't tried them yet.

On my homegrown evaluation board I take 5v in and have a local 3.3v regulator, with capacitors on the regulator's in and out pins. I'm not doing anything special with the IO, other than a resistor + zener on the serial RCV to clamp incoming serial at 3.3v .

- Sun Apr 05, 2015 10:14 am #13564 I found the ESP8266 modules to be quite stable actually, but very sensitive to good connections, specially when flashing new firmware and uploading LUA code to NodeMCU.

After making a protoboard adabter for my 01 modules I went from having to try to upload LUA code 5-6 times before success, to it working every single time, even with a lot longer code than I started out with. I also went from not being able to flash NodeMCU, to it working first time, every time.

Only change is, I had wires between the CH340 based programmer and ESP module before, now it is all soldered connections, and the ESP modules plugged into a 2x4 header on the protoboard.

Also bypassing the CH340 chip, and adding an external 3v3 regulator made a big difference.

Last edited by Mikey on Sun Apr 05, 2015 12:05 pm, edited 1 time in total.

- Sun Apr 05, 2015 11:55 am #13573 After some initial success, I was having a lot of "flakeyness" too.

In my case a lot of it was apparently caused by having my cheap (Harbor Freight) ammeter in the power connection, to monitor current demand by the module. Took it out and it has been solid since. The ammeter would have that crippling effect whether in the 5V or the 3.3V sections of the circuit ( "before" or "after" LD33v regulator), or even with direct 3V from batteries.

I've gone back to leaving the pins with internal pullups unconnected.

Cheers,
John

[RichardS]

- Sun Apr 05, 2015 12:15 pm #13576 Pay very close attention to:

* a power supply that can source 250mA at least for the peaks
* 3.3V to 5V or 5V to 3.3v connections make sure they are 3.3v to 3.3v
* connect "unconnected" pin appropriately if everything else above fails
* correct baud rates

Lots of people failing to provide proper power, run it from a couple AA battery and see if that helps.

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