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

User avatar
By AverageGuy
#84594 I'm using the USB to ESP8266 Serial Module TTL Wifi ESP-01 CH340G Developent Board Adapter to program an ESP-01 from this device: ... 2749.l2649
I put a small pushbutton to connect GPIO0 to ground per some instructions on Instructables. It looked like I was programming the chip. The blue light blinked while programming and it finished with the standard message
Code: Select allHash of data verified.

Hard resetting via RTS pin...

Once programmed it does nothing. I've tried blink and loading a simple web server example. I don't see anything on the serial console except a few random characters that I often see. I don't have a reset button but I did remove the device from the usb port and replace it. The web server example runs fine on a NODEMCU 8266.
When I plug it in, the blue light flashes once and the red light stays on.

Any ideas?
User avatar
By Zachrey
#84598 I recognize that last bit about hard reset via RTS pin. It sounds like it flashed just fine. Are you on Linux?

I noticed that some ESP modules have the "Built-in" LED on different pins. What board are you selecting on the Arduino IDE?

One thing you could try is selecting "generic esp8266 module" as your board and then dropping down and look for "built-in" LED and try different pin assignments. On my system, the default is pin "2", whatever that is...

You could also play with the baudrate on the "Serial Monitor" until you get something intelligible.
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By AcmeUK
I don't see anything on the serial console except a few random characters

That will be the boot messages at 74800 baud. If you have a programming (not program) issue this should help you.

There is a technical reason why the ESP8266 starts up with the 74880 baud rate, if you want to know why see here:-

74880 is not a standard baud rate and hence is not supported by all terminals. I use CoolTerm see here for details:-

However I think that the Arduio IDE now supports 74880.
User avatar
By AverageGuy
#84603 I am running Linux, yes. I can only tell you I it's a esp-01s. I've read elsewhere that the led is tied to the transmit pin so I understand why it might not work. As far as the serial not working, I have very early in the web server code set the speed to 115200 and printed a message, which doesn't show up. I looked at my router and didn't see the esp connect. All my other esp devices show up.

The system doesn't like 74880.
On the command line right after the Hard resetting...
Error while setting serial port parameters: 74,880 N 8 1
Error while setting serial port parameters: 74,880 N 8 1

I'm fairly certain it's being programmed, since the console messages indicate so.

Can I assume if I unplug the programmer and plug it back in (with the esp still attached) that the esp would start running, or do I have to do something special?

I did select the esp8266 generic.