ESP8266 Community Forum

- Thu Aug 06, 2015 5:09 pm #25234

The previous poster is simply intent on attacking me and is not attempting to help.

Just as a reminder about the fact : viewtopic.php?f=13&t=3729&start=10#p21722

- Thu Aug 06, 2015 6:11 pm #25237 The post you refer to has been proved wrong and was mis-stated by the poster whose English understanding is not the same as an English user . Read down further . You have been proved wrong on GPIO2 but won't admit it . You need to understand that constantly contradicting my posts and following my posts around will not achieve anything for you , me or anybody else . Is that the best you can do? Its time you grew up.

Last edited by tytower on Fri Aug 07, 2015 2:43 am, edited 1 time in total.

Get you modules here:

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

- Thu Aug 06, 2015 6:57 pm #25241

You have been proved wrong on GPIO2 but won't admit it .

Please, give us the quote here !!!
(because I don't have to admit anything, the engineering facts are there : https://github.com/esp8266/esp8266-wiki ... ot-Process)

- Sat Aug 08, 2015 4:17 pm #25384 To go back to the OP, the wiring for GPIO0 and GPIO2 is not causing the problem IMHO:

• GPIO0 is pulled up by R2 when the adapter is disconnected, and driven by the adapter's active low DTR signal when connected, which enables the UART download mode when low, and normal Flash boot up when high.
• GPIO2 is pulled up internally, however, as @martinayotte said, I would strongly recommend adding an external 10k pullup resistor on GPIO2, as you will get a much better noise margin than with the internal weak pullup resistor and thus be less sensitive to garbage on this signal. Every serious ESP8266 board is doing this, for good reasons (NodeMCU v0.9, NodeMCU v1.0, Huzzah). Leaving such an critical pin unconnected is calling for troubles: it may work in the lab, but will fail in real world situations when you get a strong electromagnetic field (such as thunderstorm) or ESD

The power supply wiring is probably the cause of the problem: the 100 nF C1 decoupling capacitor is certainly not sufficient to handle large power draws, such that when the ESP8266 turns on WiFi, I recommend at least adding a 10~100 µF capacitor in parallel. Again, all serious boards are doing this. The fact that the board is working with the adapter attached may come from additional decoupling built into the adapter and/or the adapter bringing some juice from the USB bus.

Also, make sure your power supply is able to handle the peak current of 250 mA, I would recommend doubling this figure just to be safe.