In my previous post, I made a simple variable power supply intended to power my ESP8266. I hooked it up and was having some problems. This is what I found….
For this test, I am going to keep it simple. I am going to use my FTDI USB to serial cable and see if the ESP8266 reboots when I pull the RESET pin high or low (since I can’t find documentation on which polarity the RESET is). Here is a simple diagram of the setup.
(Click on diagram to enlarge)
Never got to the toggling test. The ESP8266 would never even boot up.
- Probing the LM317 output was showing only about 1.01V being output. I checked the data sheet and it should be able to output 1.6A.
- Maybe a big spike during boot up?… So I added a 2200uF cap on the LM317 output. That still did not help.
- Probed the 9V battery and it was down to only 2.6V.
- I took out the 9V battery and used the 5V supply from my Arduino board. The LM317 output was regulated to 3.3V as expected. When I used this setup, the ESP8266 booted with no issue.
- ====> The 9V battery is too weak!!!! I did buy the battery at the 99 cent store. Wonder if all 9V batteries are like this so need to go buy a name brand battery to try.
I replaced the 99c store 9V battery (Eveready) with another brand from the 99c store (Sony). Everything is working great! I am surprised how big a variance there is with batteries. I guess you get what you pay for.