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How to connect Solar panel to Arduino MKR 1400
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How to connect Solar panel to Arduino MKR 1400

by physicsUofR on Sun Jul 28, 2019 3:08 pm

Hello,

I have bought the following kit: https://www.adafruit.com/product/390 and the following solar panel https://www.adafruit.com/product/200.

I have read this guide https://learn.adafruit.com/usb-dc-and-s ... ly-charger and was wondering about specifics of how to connect projects.

What I need to do is to connect it to the Arduino MKR 1400. Now I do not think it would be a good idea to connect the load end of the charger directly to the pins of the MKR 1400. When the MKR 1400 needs to send a text message the current draw can be 2A and the pins can't take that. Also, I am not sure if it is supposed to run that way anyways.

What I think would work best is to connect the load end to the MKR 1400's lithium-polymer port. I think I could to that by soldering two of the load attachments given in https://www.adafruit.com/product/390 and then plugging one end to the load of the charger and the other into the MKR 1400.

I also saw in the guide previously mentioned something that looked like a USB attachment connected to the load but I could not find a link to buy it. I think that would work too since the MKR 1400 has a micro USB port.

I guess another good question to ask is what is the voltage coming out of the load port of the charger? The MKR 1400 is designed for 3.7.

Is that the best way to go about this or is there some better way?

Sorry if any of this sounds elementary. I do not have much experience in this so I thought I would ask for advice.

The materials for the project I am working on is on GitHub: https://github.com/PhysicsUofRAUI/binTempSensor and I also wrote an instructable about where the project currently is here https://www.instructables.com/id/Remote ... e-Sensing/.

Any help would be appreciated!

Cheers,

physicsUofR
 
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Re: How to connect Solar panel to Arduino MKR 1400

by adafruit_support_mike on Mon Jul 29, 2019 3:50 pm

The Solar Charger connects the solar panel’s output directly to the LOAD port when the panel is active, so it in high-sun conditions the voltage can approach 6V.

If your MKR1400 needs high current for cell transmission, it will probably be best to ignore the Solar Charger’s LOAD port and connect to its BAT port. That’s equivalent to connecting the LiPo directly to the MKR1400 and letting the solar panel recharge the LiPo.

That connection is a little less energy efficient than using the LOAD port, since any energy from the solar panel that doesn’t go to the load or to charging the LiPo is wasted, but your requirement for high current outweighs that. You could run other parts of the system that use less current and are more tolerant of higher supply voltage from the LOAD port.

adafruit_support_mike
 
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Re: How to connect Solar panel to Arduino MKR 1400

by physicsUofR on Tue Jul 30, 2019 10:25 am

Thanks for your help!

Is there some way to connect a lithium polymer battery and the MKR 1400 to the solar panel at the same time?

Then the battery can supply the high current when needed and it will charge when high current is not needed.

Cheers,

physicsUofR
 
Posts: 5
Joined: Sat Oct 06, 2018 2:09 pm

Re: How to connect Solar panel to Arduino MKR 1400

by adafruit_support_mike on Tue Jul 30, 2019 1:45 pm

You can connect a JST-PH2 jumper between the Solar Charger’s BAT pins and the MKR1400’s JST jack:

https://www.adafruit.com/product/261

The BAT pins are connected directly to the LiPo’s positive and negative lines on the Solar Charger.

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Please be positive and constructive with your questions and comments.