ESP8266 Community Forum

- Wed Jun 10, 2015 10:31 pm #20110 Hi there.
I just successfully flashed my ESP-01 with

Code: Select allnodemcu_lastest.bin

using

Code: Select allespytool.py

Now I want to send AT commands.

After flashing, I unpowered, removed connection to GPIO0, and repowered.

I tried

Code: Select allscreen /dev/ttyUSB0 9600

and it takes me to a blank terminal. I try to type, and nothing shows up. I tried baud rates of

Code: Select all57600

and

Code: Select all115200

, but neither of those worked either. On all three baud rates, when I cycle power, I get some jibberish question mark things in the terminal.

Anyone have an idea of what my problem might be?

- Thu Jun 11, 2015 5:17 pm #20204 When the chip fires up it shoots out some stuff on 75800 baud or thereabouts . Then it switches to another baud rate which on my modules is 115200. Thats probably what you are seeing . Change to 75800 and have a look . It might be continually resetting.

Get you modules here:

https://www.banggood.com/custlink/KvGGhGF4wG

- Thu Jun 11, 2015 11:50 pm #20226 Thanks for the suggestion. I tried that baud rate, and lots of others. They're all yielding the same results.

[code]�<Վ���8�
���8����<Y����<��
�

[/code]

To confirm, I'm using a USB-TTy cable. I have the following connections:

USB GND -> GND
USB RX -> ESP TX
USB TX -> ESP RX
+3.3V -> ESP VCC
GND -> ESP GND
+3.3V -> ESP CH_PD

I've also tried connecting ESP RESET to +3.3V (HIGH).

Any other suggestions?

- Fri Jun 12, 2015 12:33 am #20230 I'm not familiar with a "USB-TTy" Is that the same as an FTDI cable?Mine was putting out 4.76 Volts I found so I should have had a 3.3V one . Used a couple of diodes in series to drop it .

Your connections look right but I'll stick my note on the ESP12 in here just in case . When you flash GPIO0 is kept low and when running High or floating but I notice mine keeps running after loading until a reset occurs.

Actually someone else quoted that frequency as 74800 or so . try that then you might have to look it up for the right one . I'll come back and edit it when I can. User cal says

The boot code uses 74880/115200 until the firmware sets otherwis...

Attachments

Get you modules here:

https://www.banggood.com/custlink/KvGGhGF4wG