ESP8266 Community Forum

- Sun May 17, 2020 6:48 am #87157 Hello,
I'm new to esp8266 - I've decided to start my adventure using prototype board. So I soldered some wires to ESP12E, placed it on a prototype board with regards to all the instructions I've found on the internet (RST, EN and GPIO0 pulled up with a 10k resistor, GPIO15 pulled down with a 10k resistor, 3.3v from external power source managed by LM317). It all went fine, I was able to program ESP by pulling down GPIO0. My first project was using GPIO2 as an input and maybe that's important.
Now I've decided to move to PCB. I did everything as previously with one exception - LM1117 instead of LM317 and SMD items instead of THT. Double checked all the connections with a multimeter - all looks fine. However, despite GPIO15 is pulled down with a 10k resistor, when I debug my serial connection I see either boot mode 7,6 or 5,6 (depending on GPIO0 state). I'm not able neither to program ESP nor run the code.
I've read probably most topics on different sites, double, triple checked GPIO15 connection. I've even made a new PCB, soldered ESP once again - the same problem. Tried to short-circuit GPIO15 to GND - no result.
Do you have any ideas what alse can I check? Did anyone have the same problem?

- Sun May 17, 2020 12:49 pm #87162 I still can't get to the bottom of it. I have some AI tinker boards and they say from memory 0 and 15 low and no mention of 2. Other sites say 0 and 15 low 2 high. I have just seen one site saying 2 high 15 low and 0 is linked to high and low through resistors.

I can upload with some settings but get no output and can get output without being able to upload using a TTL. I have it working at one point but it would not download updates from a website.

Saying all that I brought one of these https://www.amazon.co.uk/gp/product/B07 ... UTF8&psc=1
and that does everything I just do not know how.

I am about to write a program to try every variation out as I have now put some jumpers on 0, 2 & 15.

Part of your problem is you are using 2 and a user Lotus something has just posted about a similar problem with an ESP01.

- Sun May 17, 2020 1:42 pm #87164 gpio2 has to be high during boot for flashing and executing your sketch.
gpio2 low during boot enters specific mode that is not usable for you.
so be cautious when using gpio2 as input for external hw/sensors!

- Mon May 18, 2020 4:30 am #87178 The magic mushr... uhm mode settings are in our Wiki


0 Low - 1 High - x floating

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.