Hello all,
I am very new in this arduino universe. I have a 3D printer I use for printing nice objects, but I would like to rise to another level, with electronics. But I am fully new, sorry if I ask stupid questions or if my subject does not belong here...
I took some time on the internet to find a way to do an autonomous camera (bird camera trap). The goal is to take a photo each time a bird gets close to the bird feeder I am building. I would like to have no connection, fully autonomous system :
Photo stored on Micro SD, system power with solar panel.
Apparently, ESP32-CAM would be the perfect card, along with PIR sensor (I found the HC-SR501).
For power I checked a long time and found this setup : Solar panel 5V connected to TP4056 (with protection), connected to battery 3.7V Li-ion 18650, connected to DCDC converter MT3608 (3.7V to 5V) connected to the ESP
Looking deeper into topics, I found a lot of people advising these cards, but also others, so I am quite lost and would like your help about my specific project.
You need a load sharing charger board for the battery. The TP4056 is not designed to charge a battery if the battery is connected to an active circuit, so the circuit you posted is unsafe.
Also, it is silly to use a 5V boost converter to power the 3.3V ESP32 from a LiPo cell. If the ESP32 module has a low dropout (LDO) linear regulator connected to the 5V input, you should be able to power the ESP32 by connecting the battery directly to the 5V input.
If not, use a LDO linear regulator between the battery and the 3.3V power input. The regulator chosen should have a dropout voltage of less than 100 mV.
Not for the case of a 3.4 V LiPo powering a 3.3V circuit. The power loss is (3.4 - 3.3)/3.4 = 0.03 (97% efficient), whereas boost converters typically operate at 85-93% efficiency, multiplied by a (typically linear) regulator loss of (5-3.3)/5 = 0.34, or 66% efficiency.
The latter is a rather large waste of power.
EDIT: end of battery life voltage assumed. The situation is a bit worse assuming 3.7V input, but the LDO still wins by a long shot.
Hello all, thanks a lot for your answers !
I saw the adafruit board, but this looks too expensive compared to the rest of the build, also, I don't find any shipment to France.
The Module Kmin is sharing looks good, as it is cheap and contains already the battery holder, but I did not get if this has a regulator in it ?
For solar panel, it looks more complex to what I expected, I would try first to make the system on a simple battery, adding solar panels later on...
Also turning off the system during night is a good point ! I'll check this, maybe a simple clock integrated to the code would work ?
Concerning regulator, I understand the efficiency is bad with TP4056 and I should find an LDO, i'll look for it But if I power the board through the 3.3V with LDO, how can I power the PIR with 5V ?
srnet, I did not check that, good question, how can I do ?
For now I only know idle of the PIR is < 50 μA
Knowing the sleep current is vital, if its low, then no big deal, if its not low then you could need large solar panels, heatsinks to keep stuff cool etc.
thanks for this tutorial, it looks similar to what I want to do ! For now I have no parts in hand, I was planning to buy everything at the same time. i'll do so and verify the power consumption
Concerning solar panel, I found some solar panels with integrated battery delivering 5V for very cheap, I would use them to simplify the build. Do I still need to regulate the tension out of it ? I am not so sure as it is meant to charge security cameras or phones.
Waveshare has regulated output for 5V and for 3.3V.
Doesn't make much sense. If you don't use panels, I suggest to use Esp32 board that has battery management built in. Instead if you want panels, you need charge controller/power sharing board that is specifically designed for solar.
That might be good option, but without knowing the specific device, difficult to comment.
Doesn't say a lot.
It likely works, doubts are efficiency and behavior when you put Esp to deep sleep.
Also, probably the assembly is carefully glued and there's no way to change the battery.
OK thanks!
I think I'll do a first version without solar panel. But I understand not all esp32 cam have the battery management built in ? How can I fi'd these specific ones?
The term ESP32CAM is normally meant to mean the one you posted a picture of, not aware myself of any of those that have battery management, but maybe .............
That's easy and safe option. But many power banks have current detection and they turn off when you put Esp to sleep. You need to try some...
I still think that waveshare might be best option, It has MPPT, battery holder for li-ion cell and connector for lipo battery, 3.3V and 5V outputs and decent documentation on their wiki. I have personally never tried though...
But if I power the board through the 3.3V with LDO, how can I power the PIR with 5V ?