ESP8266 Community Forum

- Thu Sep 22, 2016 3:39 pm #55542 I know that I must be doing something wrong. I have had several boards made with the ESP-12F and I can't upload a sketch to any of them. In every case I get the "cant receive slip payload data" error repeated 8 times. I am pretty confident of the boards. I have a good 5V power supply and a 3.3V voltage regulator with the required caps. All the GPIO pins are pulled up or down as required, except that GPIO-0 is pulled up to 3.3V and then pulled low by the DTR pin, ala Sparkfun Thing Dev.

I am thinking that the problem might be with my Arduino setup. And for that, I selected the Generic ESP8266 Module for the board and upload speed of 115, 200 baud. I am using a FTDI1232 USB to UART.

This is the board I am using. http://www.electrodragon.com/product/esp-12f-esp8266-wifi-board/

I have searched for the error message and the only specific solution relates to a Mac driver. I am using a PC and as I said, the Arduino IDE. What am I missing?

My schematic:

- Thu Sep 22, 2016 6:09 pm #55549 Ok, here is a clue. I just tried shorting the GPIO-0 pin to ground and then re-powering the board. This time I was able to upload the sketch. So the DTR trick to temporarily toggle GPIO-0 low seems not to be working and is causing the error. I thought I made the circuit the same as the Sparkfun Thing board in this respect but something must be different.

Here is the schematic for The Thing.

Oh wait! I just noticed that DTR also hits Reset! I think I have my solution. Sorry if you spent much time thinking about this problem.

- Fri Sep 23, 2016 9:00 pm #55594 This is getting tiresome. I soldered on a 1 uFceramic capacitor between the DTR line and the reset pin, as in the schematic for The Thing. I expected that would solve my problem, and it did put an end to the annoying slip payload data message. But I STILL cannot upload a program to the ESP-12. Now it is just the familiar:

warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed

Does anyone have a suggestion? I would love to get past this.

- Sun Sep 25, 2016 9:01 am #55673 For those who read this thread in the future, there are two things worth noting. First, the original error message, in my case at least, was related to GPIO-0 not being pulled low at the same time as the ESP is being reset. The second thing is that some ESP-12F devices cannot use DTR to reset the chip as seen in the schematic for the Sparkfun Thing (not the Dev version). At least they cannot use it the same way as in that schematic. DTR can be used however if you connect it through a 100 nF capacitor to CH_PD (the enable pin). I eventually found this page that explains it all. I hope this helps some people in the future.