Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

User avatar
By bighairyg
#47887 Hello,

I will admit, I am new to Arduino and the whole mcu community. I recently picked up a couple ESP-01 modules to put together some projects with Arduino Nanos, and once I got them set up properly, they work awesome. The problem I am having is with an ESP-07 module that I have. I have tried it now with three different setups (different mcu, wiring, and logic-level converter, on it's own power supply or on the Arduino 5V with a LM1117 regulator). I cannot communicate with the ESP-07 (aside from a couple random instances that the ESP download tool was able to connect to flash different firmware). I tried several different firmwares on it, including NodeMCU, but ESPlorer could not get a response (and neither could the serial monitor in the Arduino IDE).

Now, from what I understand, ALL of the ESP8266 modules (regardless of form-factor) run on 3.3V, and the 'receive' line must be converted to 3.3V to prevent damage to the unit.

The best that I could get out of it is the red power LED, followed by a couple quick flashes of blue LED (normal boot-up sequence), but ZERO communication (I only have the Arduinos to connect it to, I do not have any other converter). After several hours of reading multiple internet sources and testing, I assumed I just received a bad module. It's ok, it's not the first time, and probably won't be the last. So I thought, what the hell? Let's just run the TX and RX lines straight from the Uno to the the ESP-07 and see what happens. To my surprise, EVERY command issued (using AT firmware) was immediately followed by a blue LED flash and an immediate response in ESPlorer. I ran through a series of commands, and all of them completed successfully, with no errors.

Now, I guess my question is, is this safe to use it this way? I don't have any planned projects to use this one yet. The reason I bought it was to possibly build something using the extra IO ports that it has, but it might still get used connected to a Nano. Now that it is working, I would hate to burn it up by using the wrong voltage. Any assistance would be greatly appreciated!!

FYI: After communicating with it without the logic-level converter, I wired it up with one that I know is working (no problems with the ESP-01 units) and received the same results, no response.