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Newb programming ESP-01 using Arduino Uno, questions abound

PostPosted: Sun Dec 24, 2017 3:46 pm
by magpie_lark
Hi Folks! I'm new to electronics tinkering and wanted to ask some advice for using an Arduino Uno to program an ESP-01. I looked at a few tutorials and either did not have the exact parts, or was not willing to try certain things, so bear with me...

This tutorial from IOTguider looks pretty simple, but I don't have a voltage divider on hand. I do have a dual-voltage breadboard power adapter and a 2-channel logic level converter on hand, though. Also, I was unwilling to directly connect the TX/RX pins from the Uno to the ESP-01 without at least some confidence that the 5v signal from the Arduino wouldn't damage the ESP-01.
I connected the + and - from the 3.3 v rails on the breadboard to VCC and GND on the ESP, and to the LV and GND on the the LLC, and connected the 5v + and - rails to the HV side of the LLC. I then connected the (confusingly labeled) RX & TX on the Uno to the RX and TX on a the LLC, then RX & TX on the ESP-01 to TX & RX on the LLC. I then connected the CH_PD pin to 3.3v, GPIO_0 to ground, plugged in the Uno, and hit the switch on the breadboard power supply. I hit the power switch on the ESP and plugged in the Uno. Power LED lights up on the ESP.
All of the tutorials I saw said to load a blank sketch onto the Uno and ground its reset pin, and when I plug in the Uno to USB, the signal from the USB will bypass the MCU on the Uno and go to the ESP-01. This did not appear to happen. The Arduino IDE only recognized the Uno on the com port, and that was that. An attempt to upload the ESP-01 sketch threw error messages consistent with trying to load a sketch onto the wrong chip.

Should I even bother continuing? Does anyone have a good tutorial for attempting this with a more step-by-step explanation? Is it safe to wire the TX and RX pairs directly from the Uno to the ESP-01? Do the Uno and the ESP have to be hooked up to the same power supply?