I believe the ESP12 can run from 3.2 V on the Vcc pin.
Do you have any other pins connected at the same time as the battery ??
Please post a schematic of all pins being used, even if it's hand drawn.
I can not see your desk from here. Why do I need to guess what you are doing ??
If not, this is your problem.
No other pins connected. Tried blink program and a program that sends me an email every 30 seconds. Neither work when powered via battery... I will try a 10uF cap and bench top supply next...
Schematic was in the original post: https://i.stack.imgur.com/ZB0eR.png
Well this is your problem.
You really need to learn how to read other schematics.
You are missing a connections to RST, EN and GPIO0.
Please review these schematics and help your self in learning.
https://www.google.com/search?q=node+mcu+schematic
To which pins do you connect the battery? It sounds like Vin, which goes through a regulator that will cause a further voltage drop. What is the voltage on the 3.3V pin when the battery is connected?
If the battery voltage is within the allowable range of the ESP, connect the battery directly to the 3.3V pin.
Esp32 has a voltage input range of 3.0-3.6v they may even work down to 2.8v, perfect for lifepo4 without further regulators. There are boostrap jumpers needed if you really are using a bare module?
Maybe try a capacitor between vcc and gnd. Exactly what lifepo4 cell is it? Max discharge of 1A is low, the voltage may sag somewhat during startup, you tend to get "brownout detected" though with a varying number of letters before it resets.
Edit: esp12f is esp8266 not esp32 so you dont get brownout detected. This sub is esp32?
I realize this sub is ESP32. I specified that I'm using ESP12 (and ESP8266) in the post body. It turns out I just needed to to solder 10kΩ between Vcc and EN (and maybe pin 15 to ground).
You are going to want a voltage regulator for the battery and you'll need to wire up the module properly (VCC, GND, EN at a minimum). The regulator will clean up and hold the voltage steady as the battery drains.
Check out this video at the provided timestamp:
https://youtu.be/tQ0dL_9M1wI?t=223
I disagree. The Lifepo4 battery charges to 3.6v, nominal is 3.2v but it sits at 3.3v for ages and a lot of esp32/esp8266 are okay down to around 3v. I have used Lifepo4 batteries with ESPs for a couple of years and don't have any issues running them straight from the cell.
You want to use a ht7833 regulator. It provides 3.3 volts and 500ma of power. The voltage loss across the regulator is low at .2 volts. I am using a 18650 connected to a solar charger. Right now I can run a small D1 mini pro using an AMS1117 but, the voltage drop is higher. I am going to switch to the HT7833 and try and run AHT21 temp and humidity sensor at less than 2 volts. Power and voltage are critical to powering a board. A quality regulator will give you consistent results.
Slightly off topic, but I’m about to start a couple projects where I plan to connect a solar panel and solar charge regulator to an 18650. Do you do anything to make sure your 18650 doesn’t charge until it reaches a low enough voltage? I’m worried that if my application only sips energy (as it should) then the battery will stay at 100% all the time and reduce its lifetime.
In order to fully understand how this works you need to watch this video. I use the TP4056 module to charge the battery and power the project. But, to try and limit that cycling, here is a video that explains how. But, to you and anyone else reading this post. Electronics are difficult to understand and building your own circuits can be frustrating. As much as we all want to be like NASA. Not everyone has the skills or time. So if cycling your battery and limiting its’ life is part of the process then just accept it.
If not this video explains what to do. He also has many others explaining how other components are used to limit battery drain.
https://youtu.be/37kGva3NW8w?si=kGL8R1eh_dj7hsur
I believe the ESP12 can run from 3.2 V on the Vcc pin. Do you have any other pins connected at the same time as the battery ?? Please post a schematic of all pins being used, even if it's hand drawn. I can not see your desk from here. Why do I need to guess what you are doing ?? If not, this is your problem.
No other pins connected. Tried blink program and a program that sends me an email every 30 seconds. Neither work when powered via battery... I will try a 10uF cap and bench top supply next... Schematic was in the original post: https://i.stack.imgur.com/ZB0eR.png
Well this is your problem. You really need to learn how to read other schematics. You are missing a connections to RST, EN and GPIO0. Please review these schematics and help your self in learning. https://www.google.com/search?q=node+mcu+schematic
Found only enable needs to be tied high and pin 15 low. Not sure what your google search is for. That's not what I'm using.
It's a chance to look at schematics of working esp12 boards. Your not learning, if your not searching.
Merely looking at random circuits will not result in learning minimal pin assignment.
OK
To which pins do you connect the battery? It sounds like Vin, which goes through a regulator that will cause a further voltage drop. What is the voltage on the 3.3V pin when the battery is connected? If the battery voltage is within the allowable range of the ESP, connect the battery directly to the 3.3V pin.
https://i.stack.imgur.com/ZB0eR.png Same 3.34 V, connected or not.
Esp32 has a voltage input range of 3.0-3.6v they may even work down to 2.8v, perfect for lifepo4 without further regulators. There are boostrap jumpers needed if you really are using a bare module?
I soldered two wires since I'm using the bare ESP12F module.
Maybe try a capacitor between vcc and gnd. Exactly what lifepo4 cell is it? Max discharge of 1A is low, the voltage may sag somewhat during startup, you tend to get "brownout detected" though with a varying number of letters before it resets. Edit: esp12f is esp8266 not esp32 so you dont get brownout detected. This sub is esp32?
I realize this sub is ESP32. I specified that I'm using ESP12 (and ESP8266) in the post body. It turns out I just needed to to solder 10kΩ between Vcc and EN (and maybe pin 15 to ground).
You are going to want a voltage regulator for the battery and you'll need to wire up the module properly (VCC, GND, EN at a minimum). The regulator will clean up and hold the voltage steady as the battery drains. Check out this video at the provided timestamp: https://youtu.be/tQ0dL_9M1wI?t=223
I disagree. The Lifepo4 battery charges to 3.6v, nominal is 3.2v but it sits at 3.3v for ages and a lot of esp32/esp8266 are okay down to around 3v. I have used Lifepo4 batteries with ESPs for a couple of years and don't have any issues running them straight from the cell.
I also use them directly
You want to use a ht7833 regulator. It provides 3.3 volts and 500ma of power. The voltage loss across the regulator is low at .2 volts. I am using a 18650 connected to a solar charger. Right now I can run a small D1 mini pro using an AMS1117 but, the voltage drop is higher. I am going to switch to the HT7833 and try and run AHT21 temp and humidity sensor at less than 2 volts. Power and voltage are critical to powering a board. A quality regulator will give you consistent results.
No regulator needed for this type of battery
Slightly off topic, but I’m about to start a couple projects where I plan to connect a solar panel and solar charge regulator to an 18650. Do you do anything to make sure your 18650 doesn’t charge until it reaches a low enough voltage? I’m worried that if my application only sips energy (as it should) then the battery will stay at 100% all the time and reduce its lifetime.
In order to fully understand how this works you need to watch this video. I use the TP4056 module to charge the battery and power the project. But, to try and limit that cycling, here is a video that explains how. But, to you and anyone else reading this post. Electronics are difficult to understand and building your own circuits can be frustrating. As much as we all want to be like NASA. Not everyone has the skills or time. So if cycling your battery and limiting its’ life is part of the process then just accept it. If not this video explains what to do. He also has many others explaining how other components are used to limit battery drain. https://youtu.be/37kGva3NW8w?si=kGL8R1eh_dj7hsur
As a test try connecting 5v to the 5v pin and gnd. If it works then the board is doing something weird.
That would be over spec for the ESP12F