Trouble Getting An ESP8266 Wifi Module To Work - Even With Parallax Serial Terminal

Mahonroy

Hey guys,
I am attempting to get an ESP8266 Wifi module up and running with the propeller. From what I have read, the first step is to connect to the ESP8266 through a USB-to-serial cable through a serial terminal first, try sending a few AT commandss to it, to make sure everything is working properly.

Here is the pinout of the ESP8266 wifi module:


I am using the prop plug, and I have the TX of the prop plug connected to the RX of the ESP8266, and the RX of the prop plug connected to the TX of the ESP8266. GND to GND. I am using a 3.3v voltage regulator to power the ESP8266, and not using the +5v on the prop plug. I have also experimented with running the 3.3v to all 4 pins in the center of the ESP8266, even though supposedly its not necessary.

After this is wired up, I opened up the Parallax Serial Terminal, and am attempting to write AT commands to it to see if its working. Supposedly sending "AT" and I should get a response of "ok". I have also tried all of the baud rates... supposedly these modules can be factory set up to 9600, 57600, or 115200. I have yet to get a response back from the ESP8266. I also am not seeing it broadcasting itself in the wifi (supposedly you will see something like ESP_****** when looking for wifi networks.

Am I doing something wrong? Am I not using the parallax serial terminal properly with this? Any help is greatly appreciated, thanks!

xanadu

Which 3.3v regulator? On a Prop board? Should be enough power. You sure about TX and RX? RST and CH_PD need to be pulled high.

My saving grace was -

1. Build a solid breadboard environment with prog and rst buttons
2. Pull any unused GPIO high
3. Flash the firmware until it works

I would also reccomend flashing NodeMCU - http://www.whatimade.today/loading-the-nodemcu-firmware-on-the-esp8266-windows-guide/

Also check this out - http://www.esp8266.com/wiki/doku.php?id=getting-started-with-the-esp8266 (about 3/4 of the way down "Basic Wiring")

Mahonroy

xanadu wrote: »

Which 3.3v regulator? On a Prop board? Should be enough power. You sure about TX and RX? RST and CH_PD need to be pulled high.

My saving grace was -

1. Build a solid breadboard environment with prog and rst buttons
2. Pull any unused GPIO high
3. Flash the firmware until it works

I would also reccomend flashing NodeMCU - http://www.whatimade.today/loading-the-nodemcu-firmware-on-the-esp8266-windows-guide/

Also check this out - http://www.esp8266.com/wiki/doku.php?id=getting-started-with-the-esp8266 (about 3/4 of the way down "Basic Wiring")

I'm using an external 3.3v regulator.

So you were not able to communicate with the ESP8266 until you flashed it? Can I use the propeller plug to flash it?

xanadu

I was able to communicate. When the ESP boots it sends ASCII over the serial connection. You can just hit reboot until you see something, no need to send AT commands.

You mentioned not pulling the center pins high, two of them need to be. Do you have RST and CH_PD pulled high?

Yes, the Prop Plug works great with the ESP8266

Dr_Acula

Maybe go back a step and leave out the esp module and join tx to rx and test you get an echo on a terminal program.
No need to reflash anything - it adds another layer of complexity.
Most modules are 9600 baud default.
I've found there are lots of ways to lock up the module and the easiest solution is a hard reset by toggling the reset pin low then high before doing anything else. That produces a signon message and the led will flash on the module.
Then try sending AT, and need a carriage return line feed after that, ie ascii 13 then 10. I have a feeling the parallax terminal may only send an ascii 13, and then the module will just hang waiting for the 10.

Mahonroy

Thanks for these tips, I will try them in the morning.

How do I send the ascii 13 AND 10 in the terminal? I have just been pressing the "Enter" key on the keyboard and it seems like its accepting it. Is there a way to type in an ascii code from the keyboard?

Cluso99

Ctl-M is cr and a Ctl-J is lf on most terminal programs.
As already said, join tx and rx on the prop plug and check that works first.
Use 5k to 10k pull-ups, not directly connected.
BTW there is an older esp8266 thread that probably shows a pic of the required connections. My esp8266 was running at 115,200,