Solar panel + ARDUINO - Battery supply from solar panel + battery charging

Hello,

I am asking you for advice on how to solve the topic of Arduino power supply.

I developed a car alarm design on the Arduino Pro mini clone. The supply voltage is max 5.5V and I would not like to power the entire system from the car's power supply. I would like it to be a separate system.

I was considering battery power, but such batteries will probably need to be replaced often. That's why I thought that maybe a solar panel is an interesting solution. I bought the cheapest 6V 0.6W panel on eBay.

I use end stops in the system, so I would like to have 5V in the system. I suppose that one such panel is not enough (I am still waiting for delivery from China).

Is there a simple way to power systems this way ?:
1) If the voltage on the panel is 4-5.5V then the system is powered from the panel.
2) If the panel voltage drops below 4V, the system is powered by batteries.
3) if the current above 5.5V is a powered system (I don't know why) + battery charging.

Is that something possible?
I don't know exactly about power supply, so that's a question.
The system will be used in the car and I do not want something to ignite etc. .. A fire in a car is a bad thing!

I rummage on the internet and finally found something:
link

Will such a layout allow charging the panel with battery + power supply from the panel and if necessary from the battery? Will such a system be safe?

Of course it is possible to power the system in this way. Look for the MPPT converter best. Maybe something on ebay May? I think there were also small projections in EP or EdW.
http://ep.com.pl/files/9257.pdf
She was probably also in EdW 5/2016.
Forget that a Chinese 6V / 0.6W panel is enough. Here you need at least 4 -6 pcs. As no more, but you will check how the panels will come. Because the board itself will not be connected, only some executive system, sensors, siren or whatever.
You will need these at least 4 panels for the arduino itself.
Basically as to the power logic:
- make an executive system on mosfets, preferably logic Level, and stitch logic in the Arduino module, measuring voltages through the ADC.
- make a separate comparator
Are there any ready-made modules that meet your requirements, I don't know, I've never looked.
And you can use something on the TP4056 only it must be a charger module and at the same time with the possibility of connecting a Li-on battery, the system would work in buffer mode.
Something like this:
http://www.ebay.pl/itm/1pc-TP4056-Charge-and-...945358?hash=item43f4fbb4ce:g:lB8AAOSwgmJX16dz

Or, a converter from a car battery to 5V, and 14V panels to support the battery. The sense that the car would stand for a long time. Because using it every day is probably not worth having fun.

Thanks for the answer.

I ordered 1 panel for testing - the idea for its use came up after ordering and that sometimes things from ebay have a problem getting to the destination I ordered 1pc.

My layout consists of:
2x end stop as a pull-up
1x RGB diode
1x module NRF24 nrf24l01 (3.3V)

And that would be all. Modifying the end-stop as a pull-down should probably reduce the power consumption.
6 solar panels, it will probably take me a whole trunk board

This may bite the topic from a different angle ... Do you have any suggestions?
I was thinking about a 12V battery and a step-down converter.
There was an option with a 6V battery, but here again there is a voltage problem. Because a charged battery would give 6V, which is too much. I can always connect it to RAW but I would have to switch to VCC somehow when the voltage drops to the correct 5.5V.

What do you think will be the safest solution?

tomekb411 wrote:

6 solar panels, it will probably take me a whole trunk board

This panel will have 7cmx7cm somewhere.
This alarm probably will not take more than a standard car alarm, after all it will fit in a dozen or so mA? In vigil?
Maybe nothing is necessary for the power supply except a standard battery in the car. Do it, measure the current and then see what to do next.
Arduino and NRF will take a max of 60 - 70 mA during operation. Probably almost nothing during the stand-by, only the rest of what you connect.

Or use the set: 18650 battery + TP4056 charger?
Charger connected to the car battery. If nothing would draw power from the battery when the car is stationary, you can connect the charger "after the ignition" When you start the car and go somewhere, your batteries are charged.

Thanks for your interest and willingness to help!

I would prefer not to interfere with the car's power supply. I'm not such an electrician, but rather a short circuit etc. is very easy. I don't want to ground my car for a few days / months.

I see that it would be appropriate to change the topic of the thread to something else because we left the conversation about the solar panel.

Let's stick to the rechargeable batteries, however, because a solar panel is probably a bad idea. I ordered a step-down converter a few days ago so it would be better to use it, so as not to generate costs.

How about supplying the whole system with a 12V 1.2Ah gel battery from PLN 17 for allegro? Is this an excess of form over content in my case?
I was still thinking about rechargeable batteries, e.g. from a lap battery, only that each one has probably 3.7V. But if I combined it into a set of cells, I would have the inverter voltage suppressed. And I can always recharge the batteries with a charger, which was suggested by a colleague above, e.g.

Maybe I'll explain how the alarm works to lighten my vision.
End-stops register whether the door is closed or open. The LED flashes every 1s. When the door opens, the LED turns red.
NRF sends a signal every 50ms (sample time) to the receiver. The receiver at home signals whether there is a connection or if the car is out of range. When the door opens, the NRF sends an alarm signal to the receiver. One button turns on / off a lit LED so that it does not hurt the eyes.
- in a nutshell everything is supposed to work. The design will be improved over time.

Hint something because I have been thinking for a long time and I have too many ideas at once how to safely power it up ...

If someone else liked Arduino and wanted to help gently with the code, I ask for PW ... The whole alarm works but has one weak point where it hangs and I do not know how to solve it.

Why do you send information every now and then that the door is closed?
Keep the processor asleep, and if the door is opened, just send information about this fact.

When you keep the uC dormant, even a small battery will last for a very long time

I am sending a signal all the time to let me know at home if I have a car connection. I don't send a signal that the door is closed. I only send any message to let the receiver know it is connected.

But the fact It doesn't make sense to constantly send signals, this can be extended to e.g. 5s. The fact is, the LED in the car must flash, because it is finally an "alarm".

I would put the source codes here, but I don't know which programming language to choose in CODE for arduno ... That's why I put links from Dropbox:
link
I apologize for my scribble in the code, but I programmed it as much as my knowledge would allow. Maybe someone would like to suggest what to change in the code, so that it somehow neatly walked? Currently, the effect is satisfactory for me, but sometimes something hangs. The LED should flash blue and red only when the door is open. Unfortunately, there is a moment that the opening hangs a diode that lights up blue and red.

From hour to hour I have more ideas on how to power it and I do not know if there will be any good batteries from an old laptop battery ... Since one battery has 3.7V, a set of 3 batteries will give some 11.1V which will be git for my converter step-down.

tomekb411 wrote:

3 batteries will give some 11.1V which will be git for my step-down converter.

Since you insist on powering from a separate source, why 3x Li-on?
Process from 12V (because after charging it is> 4V) to 5V is not economical enough, and you still should not discharge these batteries to less than, max 2.5 - 2.8V depending on the cell.
In this application, it should not happen anyway, they should not be able to discharge to such a value because the current consumption will not allow it
So, even when completely discharged, they will give you some voltage. There should be 2 x Li-on. So in the range of 6 - 8.4V from discharge to full charge.

Jawi_P you are probably right because I don't know each other.
I will stay with 2xLi-on and step-down

And can you suggest something about safety during short circuit of such batteries? That nothing would light up or explode here ...

I want the power supply separately because I am lucky that sometimes I connect something wrong or something and then I have a problem because something will burn. In the car, if the fuse goes, no problem. It is worse if I burn some element and then I will have more problems and financial outlays. Probably after the initial tests I will change the ideas on the battery of the car but for now it is a prototype and I need to refine it. Now the software issue remains because I have problems with multitasking and when I click the button it will not always get it ..

tomekb411 wrote:

And can you suggest something about safety during short circuit of such batteries? That nothing would light up or explode here ...

If these are stimulants from a laptop or bare cells, I see it wrong.
If secured, it's better, but I wouldn't try it anyway.

It's good that I started the thread.

This is probably the only solution is the cheapest power bank. I just have to see if everything will work, because I currently have a 16000mAh power bank, which turns off after 5s. Probably too low power consumption ...