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ESP-1 Power supply and weird Rx behavior

PostPosted: Thu Jun 08, 2017 4:19 pm
by Filas_Codes
Hello,

I am using the ESP-1 board connected using this schema:

Image

using TA-02L as USB - TTL converter.

However I am experiencing numerous issues with this wiring.

First of all, powering the ESP1 from the converter's 3V3 source is causing ESP to goes completely off while booting. It spits out boot message then goes silent with the LED turned off. Also the converter disconnects itself from the computer. This happens while in normal mode (GPIO0 HIGH). When in programming mode (GPIO0 LOW) i can succesfully flash the ESP.

I tried powering it from Arduino NANO but to no avail. However using Arduino UNO, the ESP boots just fine (Why is that?).


The next issue is about the RX pin on the ESP. If I have it connected like on the schema through the voltage divider, I can flash the ESP just fine. However, when I boot into the firmware, I cannot issue any AT command as ESP is not receiving the message (blue LED not lid). Weird thing is, if i switch the cables from voltage divider to ESP, I actually can issue AT command but cannot flash the ESP (I am not kidding). I measured the resistance of the other cable and it's just 0.1 Ohm less then the other.

However, if I connect the RX pin directly to the converter without the voltage divider, i can flash and issue commands just fine.

Also worth mentioning that i actually have 2 of those ESPs and both behaves exactly the same.

Please, help me resolve this issues as they are rendering the ESP utterly useless for me :(.

I'd be glad for any advice.

Re: ESP-1 Power supply and weird Rx behavior

PostPosted: Fri Jun 09, 2017 2:00 am
by schufti
forget the voltage divider, just use a 1k series resistor.
but life can be easier with automatic run/program, just 2 transistors and resistors not more effort than your buttons, look for nodemcu circuit and copy relevant parts ...

Re: ESP-1 Power supply and weird Rx behavior

PostPosted: Fri Jun 09, 2017 8:30 am
by atexit8
Filas_Codes wrote:I'd be glad for any advice.


The circuit you have is very fancy, but you don't all of that simply to communicate to the ESP-01 with AT commands.

Read http://www.martyncurrey.com/arduino-to-esp8266-serial-commincation/
It works for me.

Re: ESP-1 Power supply and weird Rx behavior

PostPosted: Fri Jun 09, 2017 11:59 am
by rudy
You need a decent 3.3v power supply. The 3.3v from the Uno is not adequate.