The use of the ESP8266 in the world of IoT

User avatar
By platinnguyen
#18472 Hi everybody,
I'm doing my graduation project using ATMEGA32 smd + ESP8266. But it's not working. I don't know why.

When I use UART interface of chip, I can transmit but I can't recieve data from ESP. I try UART interfae with PC, it worked fine.
Then I try Arduino Uno + ESP, it worked fine.
Can someone help me???
I nearly expired.
Thank you so much.
This link is schematic.
User avatar
By martinayotte
#18527 On your schematic, you've left the GPIO0 and GPIO2 floating. That's not good !
They needs pullups resistors to 3.3V, something like 4K7 or 10K ohms.
And when you wish to upload a firmware, you will need to short GPIO0 to GND. ... ot-Process
User avatar
By lethe
#18546 Do you use espressif's AT firmware? If so, make sure you are sending CRLF (\r\n) line endings.
Also I did not see any crystal for the AVR in your schematic, are you using the internal oscillator? I never tried myself, but several sources suggest that the internal oscillator may not be stable enough for UART. Have you checked the actual signals with a scope or logic analyzer?
User avatar
By platinnguyen
#18821 Yes, Thank your comment :) I have solved my problem.
The problem was due to my error using internal oscillator 1Mhz,
so when faulty transmission at speeds baurate = 9600.
But when I moved baurate = 19200 for mcu and ESP is running fine.
Luckily !!
Thank you very much.
Wish you have a good day!