Pican stacking with moitessier?

[MigGat]

You can follow the updates regarding the new HAT on this thread: https://forum.openmarine.net/showthread.php?tid=3284

[rszemeti]

Ah, OK,  I had seen that, but didn't think that was the board that was supposed to be like the Pican-M, as it is nothing like the Pican-M ... it doesn't have an NMEA2000 connector, doesn't have a  PSU to power the Pi from the NMEA bus and has all sorts of junk I don't want or need.

[Sailoog]

The Pican-M is a good board. The MacArthur HAT has NMEA 2000 in/out, PSU and more.

We considered including a CAN connector but that big an rigid connector caused too much mechanical stress to the HAT. Using a screw terminal you have just to cut the wire and connect H and L terminals.

Our PSU is generally used to power drones and has additional features:
- You can measure voltage and current of your battery bank. Taking power from the CAN bus you can not measure consumption of the whole electrical circuit, just the CAN network consumption. Using our PSU you still can take the power from the CAN wire if you want.
- We will have less electrical interference. We will have IMUs around so it is better to have the DC-DC conversion far away.
- Drone power modules have a very clean output.

we have endeavored to make the price cheaper than boards like the Pican-M with a lot of extra "junk" that you do not know when you will need.

[rszemeti]

I did not realise the board had a PSU built in, this is good news.   One of the problems solved by the Pican-M is the PSU. Normally I have to have an extra PSU, and it is a mess. with the Pican-M and now the MacArthur HAT the integrated PSU is a big plus, it really neatens installation. So that part is a good think, thank you.
The on board NMEA2000 connector of the PicanM is good ... but maybe I can live without it, a separate one means I can easily mount it on the side of the waterbproof box, so that is OK now I consider it.
As the only reason for me to use the MacArthur HAT instead of the PicanM is so it fits under the Moitessier HAT (and uses SPI1) the IMU etc is not really needed as the Moitessier has those already.
For battery sensing I have dedicated NMEA2000 battery voltage/current sensors near the batteries. what I don't want is hundreds of wires going from the batteries, engine etc to a single "sensor" unit ... I have an NMEA2000 engine monitor unit,  2 x dual channel battery monitor units, a 4 channel NMEA2000  tank level unit etc. This keeps the wiring on the boat simple, just an NMEA2000 bus around the boat, and units where they are needed.
Anway, thankyou for the work, where is the price of the MacArthur and where can I buy it?

[Sailoog]

The MacArthur HAT is not available yet so we do not know the price. We are waiting for the second batch of prototypes but the global component shortage crisis is slowing things down. I am afraid it will not be ready for this season.

[rszemeti]

Ah OK. In that case I may just make a version of the Pican with the SPI port selectable between SPI 0 and SPI 1 ... it should be quick and easy to do this.

[Techstyle]

do either of these HAT's include safe shutdown? in other words, do you have to power down the Pi manually or can you just turn off the supply without the possibility of it damaging/corrupting the SD card?

[Sailoog]

the recommended PSU for the MacArthur HAT does not have safe shutdown but we are exploring the options

[Skipjohnsen]

Sorry, same situation, they use SPI0 (GPIO08/pin 24).

The good news is that we are working on a new HAT fully compatible with the Moitessier HAT that will have NMEA 2000 using SPI1. Software for this new HAT is almost done and PCB design too but it will take still some months to have the first units.

Hi,  where can I order one?

[Sailoog]

https://forum.openmarine.net/showthread....4#pid21024