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Power MacArthur HAT and RasperryPI properly
#1
Reading the docs I found "Do not power the system from the Raspberry Pi and the MacArthur HAT at the same time, you must use only one power supply". I connected a 12V power source (actually 14.7V) to GND and 12V SW Following the Maiana example. I tested Maiana and worked perfectly fine, but the Raspberry is not powered.

Should I connect the same source to both 12V and 12V SW?

I mean, I tried and worked, but I don't understand the meaning of those 2 connections.
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#2
That warning means that if you are using the pololu power module to power the Raspberry you should not use the Raspberry USB-C 5V input.

If you do not use the pololu power module you need a 5V charger to power the Raspberry by the USB-C input as usual but since the MAIANA devices needs 12V, you need to connect 12V SW to the battery.

We need these 2 connections (12V and 12V SW) because 12V SW will trigger the shutdown and the system needs to be powered by 12V until the shutdown ends.

Graphically:

If you are not using neither the power module nor the MAIANA, power the Raspberry by the Raspberry USB-C input as usual.

If you are not using the power module but you are using the MAIANA, this is the wiring:

   

If you are using the power module and the MAIANA this is the wiring:

   
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#3
In early prototypes, the MAIANA was connected to 12V internally instead of 12V SW, but we noticed that when you turn off your boat's main switch, the MAIANA would still run silently (no red LEDs) and you could accidentally discharge the battery.
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#4
You can also choose not to use the main switch of the boat's electronics and use a switch to turn off only the Raspberry safely without having to do it by software.
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#5
Ok, got it. Since I have both MAIANA and the power module, I'm using the last diagram and everything is working fine.
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#6
Ah OK now I understand your confusion, first we are saying "do not connect 2 power supplies" but when you use MAIANA without the pololu power module in fact you are using 2 sources even though they are 2 totally separate circuits. I will try to add a note to the manual, thanks.
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#7
Exactly, that was what congused me, but after the explanation everything is fine on my home setup:

   

Hope I can install on the boat next week, but I lost the cap of the Maiana antenna and I need to find a replacement before I can install the whole thing on the boat.
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#8
(2023-04-07, 11:49 AM)MigGat Wrote: Hope I can install on the boat next week, but I lost the cap of the Maiana antenna and I need to find a replacement before I can install the whole thing on the boat.

I have many spare parts, I can send you one.
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#9
No problem, I already found some in a local store this morning. They are rubber, not PVC, but I hope it last long enough.. In any case, I had to buy 20, so no problem Big Grin
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#10
Hello,

About the Powermodule and the 12V Lines, the Fuse (2-5A) must be the Line to the Battery (best near the Battery), and not only in the switched Line.

ym2c - Holger

Still waiting for the Arrival to Austria...... ... it just came to my door.
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