Hi Arduino Community,
I just received ESP8266 (ESP-01) and I also got a USB to TTL adapter as well as breakout adapter so I can mount the ESP on a breadboard.
I followed a YT and I was able to download the blink sketch to the ESP and after resetting, I can connect an LED to GPIO2 and GND and it works fine.
I also tried uploading a blank sketch to the ESP and then disconnecting GPIO0 from GND and then doing a reset, but I am not successful in issuing AT commands. There is no response if I just type AT and return. If I do a reset of the ESP I see some garbage/junk show up on the serial monitor. I have tried different baud rates besides 115200.
I was wanting to do this so I can verify the the Wifi is working properly.
My final goal will be able to connect the ESP to an UNO so I can connect to my home network and monitor and control things that are already programmed in my UNO.
Any ideas on why I cannot successfully test AT commands?
I followed a YT and I was able to download the blink sketch to the ESP and after resetting, I can connect an LED to GPIO2 and GND and it works fine.
You followed a what ? Anyway once you've uploaded something onto the ESP yourself (as you say you've done with blink) You've overwritten the firmware that comes with it and therefore the ESP will not respond to AT commands anymore. You can upload (flash) the firmware again, there are several versions available and there is a choice of upload tools, but personally once i managed to upload firmware (sketches) using the Arduino IDE i never bothered about the AT-firmware anymore. The AT-firmware makes it possible for the ESP as a sort of interpreter, but a compiled sketch is both more flexible, faster and a lot easier to control.
I do hope you added a resistor within the circuit with the LED and as a recommendation, make your LED's active LOW (so connect them to 3.3v via a resistor to the GPIO pin) that way you will not switch it into an unwanted boot-mode (actually only GPIO3 the RX-pin can be safely grounded during startup) There is also a builtin LED on GPIO1 which is active LOW, and can be used if you don't use the Serial port (GPIO1 is the TX pin after all )
My final goal will be able to connect the ESP to an UNO so I can connect to my home network and monitor and control things that are already programmed in my UNO.
that should work just fine, have a look at Robin's Serial Input Basics for a means to communicate between the 2 units, though depending on what you want to communicate and how your sketch on the UNO is organized there may be other options. The ESP-01 has 4 data pins, and a lot of resources (memory & processing power) you may not need the UNO, and can let the ESP perform all the tasks.