Slow ramping voltage hangs esp32 / BOR - Brownout misbehavior or not ?
Posted: Tue Nov 28, 2017 11:32 am
Hello !
This is my first post ! Good to be here! I am an ESP32 / electronics enthusiast - hobbist, and my electronics knowledge is kind of meager, so please forgive me if my question is kind of basic knowledge.
I am trying to do a solar panel based experiment on an ESP32, with some solar panels which at peak sun deliver around 3.3volts.
If I hook it directly into the ESP32, at that moment, the ESP32 happily wakes up and executes its chores.
BUT, if I connect the solar panels at night, then sun arises and gradually powers up the ESP32, then it remains unresponsive. Most of the time it won't even revive when pressing the reset button on the board: I need to unhook the solar panels and reconnect (at good sun time) for the ESP32 to revive.
Then, as a second step I purchased a "cheap" 3.3v regulator, those that can be found on online stores carrying a description like "0.8v - 3v to 3.3v voltage step up regulator" and now my power "system" is comprised of:
Solar Panels -> Diode -> 2.7v supercapacitor -> 3.3v tep up - regulator -> ESP32
I manage to get about 3.3v way earlier on the morning, and in general, get stability for most of the sunlight period, since my code makes the ESP32 go to sleep and only wakes up to perform a sensor reading for less than a second.
BUT AGAIN: at first, when the voltage is low, and the step-up regulator cannot quite start delivering 3.3v, slowly ramping into that voltage line, will freeze the ESP32.
So I was wondering if anyone got any insights on this behavior, if it is to be expected.
I am thinking about placing a transistor which could open up voltage input into the regulator when it senses that the supercapacitor reached a viable source voltage (around 1.4 volts as I could test, instead the "advertised" 0.8 volts from the step-up / regulator).
Any idea, help or comment, please, I would appreciate it very much.
Regards, Enrique.
This is my first post ! Good to be here! I am an ESP32 / electronics enthusiast - hobbist, and my electronics knowledge is kind of meager, so please forgive me if my question is kind of basic knowledge.
I am trying to do a solar panel based experiment on an ESP32, with some solar panels which at peak sun deliver around 3.3volts.
If I hook it directly into the ESP32, at that moment, the ESP32 happily wakes up and executes its chores.
BUT, if I connect the solar panels at night, then sun arises and gradually powers up the ESP32, then it remains unresponsive. Most of the time it won't even revive when pressing the reset button on the board: I need to unhook the solar panels and reconnect (at good sun time) for the ESP32 to revive.
Then, as a second step I purchased a "cheap" 3.3v regulator, those that can be found on online stores carrying a description like "0.8v - 3v to 3.3v voltage step up regulator" and now my power "system" is comprised of:
Solar Panels -> Diode -> 2.7v supercapacitor -> 3.3v tep up - regulator -> ESP32
I manage to get about 3.3v way earlier on the morning, and in general, get stability for most of the sunlight period, since my code makes the ESP32 go to sleep and only wakes up to perform a sensor reading for less than a second.
BUT AGAIN: at first, when the voltage is low, and the step-up regulator cannot quite start delivering 3.3v, slowly ramping into that voltage line, will freeze the ESP32.
So I was wondering if anyone got any insights on this behavior, if it is to be expected.
I am thinking about placing a transistor which could open up voltage input into the regulator when it senses that the supercapacitor reached a viable source voltage (around 1.4 volts as I could test, instead the "advertised" 0.8 volts from the step-up / regulator).
Any idea, help or comment, please, I would appreciate it very much.
Regards, Enrique.