I've installed the recommended CH340G serial driver, it's detected fine as COM8 (Windows 7 btw), I connected via PuTTY, and the only thing it'll give me is the bootloader message on reset (which only appears as non-gibberish at 74880 baud):
ets Jan 8 2013,rst cause:2, boot mode:(3,6)
It accepts no input (i tried a few AT commands - nothing, not even an echo back), and I also tried at other baud rates such as 9600 and 115200.
I googled a bit and found the following suggestions:
• Use an external power supply
- I grabbed my bench supply and tried it with that on both the 5V pin (labelled Vin on the LoLin board) and 3.3V pins, no change.
• The CH340 chips are often unreliable
- I happen to have a 2102 FTDI UART-USB interface, so hooked that up. Detected as COM7, but no change.
- I should also mention I made sure the FTDI interface and bench supply had common ground.
• Try ESPlorer
PORT OPEN 74880
Communication with MCU..Got answer! Communication with MCU established.
AutoDetect firmware...
Can't autodetect firmware, because proper answer not received (may be unknown firmware).
Please, reset module or continue.
• Reflash the firmware
- Cloned and built esptool
- Created a firmware .bin using that cloud build service (can't remember the URL, i'm sure you guys know the one)
Connecting...........................................
A fatal error occurred: Failed to connect to Espressif device: Timed out waiting
for packet header
- HOWEVER, during the connection attempts the blue LED on the ESP8266 blinks a few times, suggesting it's aware something is going on.
At all stages I've used a multimeter to check continuity (I also checked to make sure my FTDI interface Tx/Rx was 3.3V and not 5V), and tried various combinations of serial interface, baud rates, power sources, and now I'm at a loss.
There's clearly something working on the ESP8266 as it does send that 1 line of data across the serial link on a reset, and there's that blinking LED when esptool tries to connect suggesting it can receive as well (although for all i know it could just be issuing a reset to the Rst pin over and over).
Anyone have any further tests I can do?