-->
Page 1 of 1

ESP-07/12 adapter plate and GPIO2 confusion

PostPosted: Wed Oct 14, 2015 1:39 am
by BlitzSSS
Hi All

I'm playing with my first ESP-07 and 12E and bought some of those cheap white adapter plates to go with. Like this http://i.imgur.com/K9UDi53.jpg

I've just spent a fair amount of time trying to understand the requirements surrounding GPIO 0, 2 and 15 on these boards (tytower vs esp8266.com ;) ) and come to the conclusion that despite the weak internal pullups GPIO2 should have an external pullup of ~4k7.

Now my confusion is with these adapter plates, they appear to have a 10k pulldown. I've quickly tested the board and with the standard AT firmware it's responding OK however is this going to give me issues when it comes to flashing?

If this is going to be an issue should I remove the resistor on the adapter plate or just use a stronger pullup?

Thanks

Re: ESP-07/12 adapter plate and GPIO2 confusion

PostPosted: Wed Oct 14, 2015 3:58 am
by torntrousers
I use lots of those boards, they're about the cheapest and easiest way i've found to use ESP-07/12's. They work fine with the existing pullups/downs on the board you shouldn't need anything else. The only mods i do is to add a jumper between GPIO-16+RST so deep sleep works. I do usually also add a couple of bypass capacitors across the power supply pins 100nF+100uF, don't know if thats really necessary but i never have stability issues like i used to get with ESP-01s. Also, i usualy use more header pins than the length of the board and short them all together to the power supply pins so there's spare Vcc and GND pins and then its easy to prototype stuff without needing a breadboard.
ESP12.png

Re: ESP-07/12 adapter plate and GPIO2 confusion

PostPosted: Wed Oct 14, 2015 6:54 am
by lethe
That 10k pulldown is for GPIO15, which needs to be low for the ESP to boot from flash (otherwise it will try to boot from SD card).

Re: ESP-07/12 adapter plate and GPIO2 confusion

PostPosted: Wed Oct 14, 2015 7:07 am
by BlitzSSS
torntrousers wrote:I use lots of those boards, they're about the cheapest and easiest way i've found to use ESP-07/12's. They work fine with the existing pullups/downs on the board you shouldn't need anything else. The only mods i do is to add a jumper between GPIO-16+RST so deep sleep works. I do usually also add a couple of bypass capacitors across the power supply pins 100nF+100uF, don't know if thats really necessary but i never have stability issues like i used to get with ESP-01s. Also, i usualy use more header pins than the length of the board and short them all together to the power supply pins so there's spare Vcc and GND pins and then its easy to prototype stuff without needing a breadboard


Thanks for the suggestions.

lethe wrote:That 10k pulldown is for GPIO15, which needs to be low for the ESP to boot from flash (otherwise it will try to boot from SD card).


Hmmm you're right, after taking a closer look I see that I'm mistaken by not taking into account the offset of the pins and the print.

Thanks, kind of a dumb mistake to make :oops: