ESP8266 Community Forum

- Thu Jul 26, 2018 4:45 pm #77433 I wish to transmit serial data (from a GPS with serial output ) via WiFi to a Windows tablet that does not have GPS. This is doable now through the purchase of a stunning expensive module that I'm sure is nothing more than an ESP8266 device (or something similar).

So, I bought myself an ESP8266 board produced by DOIT



that purports to have firmware inside to do exactly this.

I wired the module up to a Windows PC using a serial adaptor and external power supply, ran a terminal emulator, set the baud rate to 76000 and pressed the rest button.

Tada! In the terminal window, things displayed, about 20 lines of English showing dates, firmware revs, checksums and so forth. So I'm pretty sure the serial connection is correct.

From another PC, I connected via WiFi to the device and got the GUI expected (according to the TERRIBLE Chinglish documentation).

However, that documentation also suggests I should be able to type

AT

and get an

OK

and I don't. And no matter what baud rate I select, there is no response to an AT command. I've put a scope on the lines and the serial bits do get to the 8266, but the chip simply ignores them.

I've spent some time at this to no avail, and now am at something of a loss.

Any suggestions appreciated.

Alan

P.S. If there is a suggestion that says "buy this board, do what it says on that webpage and just throw your old board away", well, I'm good with that as well.

- Thu Jul 26, 2018 7:20 pm #77434 Looks like yet Another cool ESP module. I typed szdoit wifi into google and looked at the spec... it listed these baud rates:

Support baud rate (bps): 300/600/1200/2400/4800/9600/19200/38400/57600/74800/115200/230400/460800/921600/1843200/3686400；

I am having Good Luck with the seeed wifi uart that has an ESP8285 on it, same as ESP8266 but bigger flash.
So: find the default baud rate, get AT ctl-m ctlj to answer back OK. Does you usb to ttl module output 5v or 3,3v? If its 5v, does that doit module accept 5v on the rx input? (my experience with the HC-06 bluetooth modules was they needed a voltage divider). Standing by for next question.

- Fri Jul 27, 2018 2:09 am #77439 the transparent AT mode is probably only supported on the serial TTL interface.
Did you try to connect via this interface using the DoitSerialCOM.exe from WiFi-TTL_TOOLS package?

- Fri Jul 27, 2018 2:26 am #77441 I've never seen this particular board, but your idea that the ESP8266 would be a nice chip to use for these kinds of things (instead of using an overpriced out-of-the-box solution) is dead on.

I highly doubt, however, that your GPS module speaks AT-Hayes and the default ESP AT-firmare is known for it's... erm... oddness, so you'd better forget about that and write your own firmware that does what you want (believe me, it's much easier than it sounds).

About a year ago I wrote this reply to someone trying to get a $5 GPS module to work and I made a little example for him you might be able to use as a starting point.

BTW: I always use PuTTY as serial console and have to use CTR-J and CTRL+M for carriage return/line-feed.

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