ESP8266 Community Forum

- Mon Jun 22, 2015 7:32 am #21208 I have a robot (see setup below) that features:
3.3V regulator capable of something in the range .5-1A, depending on voltage input (https://www.pololu.com/product/2122)
Teensy 3.1
Windows PC (two different machines I'm testing)
ESP8266 (AT+GMR returns version 7.80.8.50)

If you are familiar with the Teensy, you know that out of the box the VUSB is connected to VIN, but rest assured that I set it up with the trace cut and some Schottky diodes so that the ESP is powered solely off of the 3.3V regulator which runs off a LiPo battery. To confirm, if the battery is disconnected, the ESP stays off.

I set up the Teensy to act as a bridge, baudrate 115200. I am using the Arduino IDE Serial Monitor window, sending both newline and carriage return after each command. I have 13 ESP8266 modules so I've also swapped these out repeatedly to eliminate the possibility that one was a dud.

When connected to one machine (Dell laptop, Windows 7) everything works.
When connected to another machine, a Lenovo Thinkpad, only AT and AT+GMR work. All other commands return ERROR.

Any clues? The main reason this bothers me is that the Thinkpad is my own computer, so I can take it back to my residence to work. But the Dells belong to the University where I am teaching, so I have to leave them here.

- Mon Jun 22, 2015 11:54 am #21237 Are you using the same terminal emulator on both PCs?

- Wed Jun 24, 2015 11:35 am #21526 Yeah I was using the Arduino Serial Monitor on both.

I have been too busy to do any further testing, but I suspect something to do with how my Thinkpad handles the usb serial comms. If I had time, I'd update the EPS8266 firmware so that I can easily change the baudrate, then try 9600 and other slow rates and see if it works. It also seems like there are two different outputs I am getting for the version command from the ESP8266, and I'm not sure what causes one (the one that says 7.80.xxx) vs the other (the one that says the SDK version as well, and is generally much more verbose).

I have a few days off soon from the class I'm teaching...I miiiight have time to look into it but I'm much more likely to just switch to using another machine.

- Wed Jun 24, 2015 12:09 pm #21528 Don't rely on the Arduino Serial Monitor.

I use CoolTerm http://freeware.the-meiers.org/

One advantage of CoolTerm is that you can set a custom baud rate of 74880 so you can read the startup messages from the esp8266 bootloader.