2023-04-21, 07:50 PM
Thank you for the detailed feedback! 
I know that the stacking header situation is unsatisfactory. "Extra-long headers" will have a gap under the HAT, with only the stand-offs ensuring proper mounting height. The correct headers would be the "double-shrouded" stacking headers available from Adafruit, Pimoroni, PiHut, etc. If anyone knows a reasonably priced source for bulk quantities of these, please let us know.
Having through-hole solder joints on both sides of the PCB is an issue for manufacturing. In volume production these are not hand-soldered but done with a selective soldering machine. Besides that, I'd be worried about clearance above display and camera connectors.
But you are right about the labels being hidden. One idea is to include a sheet with stickers that would go on all the connectors, including the detachable screw terminals. As a bonus, that sheet could also include a sticker for extra insulation on top of the Ethernet and USB connectors
There are several reasons we decided do go with a screw terminal for NMEA 2000:
1. Size: Compatible connectors occupy an area of 20x15mm on the PCB and are 17 mm high, compared to 8x7x7 mm for the screw terminal
2. Versatility: While NMEA 2000 is just CAN, some vendors have gone with different connectors for their own implementation (for example SeaTalkNG and Simnet). Plus the screw terminal is easier to use for DIY CAN projects.
3. Cost: The connector required for NMEA2000 is relatively expensive ($8-$10 in 100 quantity)
I will leave that question to Sailoog.
(2023-04-21, 02:14 PM)rszemeti Wrote: On my Pi4, the height of the pillars is correct for the board, but the connection block is about 3mm too short, only just making contact with the header on the Pi4. I pushed the connector down 1.5mm from the MacArthur and it is better, but really, it needs a longer header.
I know that the stacking header situation is unsatisfactory. "Extra-long headers" will have a gap under the HAT, with only the stand-offs ensuring proper mounting height. The correct headers would be the "double-shrouded" stacking headers available from Adafruit, Pimoroni, PiHut, etc. If anyone knows a reasonably priced source for bulk quantities of these, please let us know.
Quote:The board contacts the USB sockets, so only the solder resist on the PCB prevents a short circuit of the tracks to the USB sockets, which will happen in time. A simple solution: put some PVC tape on the top of the USB sockets to prevent the board contacting thr bare metal.
The labelling of the connections/sockets is on the back of the board. Impossible to see once the board is mounted. If the connectors were just mounted on the back of the board instead of the top, the labelling could be placed on the top silkscreen layer, which woudl make it much easier to wire up without referring back to the manual. This could be done without any board changes, just the top silkscreen would need updating and the hand soldering of the connectors made with them mounted on the bottom layer. There is enough clearance between the Pi and the board to accommodate this.
Having through-hole solder joints on both sides of the PCB is an issue for manufacturing. In volume production these are not hand-soldered but done with a selective soldering machine. Besides that, I'd be worried about clearance above display and camera connectors.
But you are right about the labels being hidden. One idea is to include a sheet with stickers that would go on all the connectors, including the detachable screw terminals. As a bonus, that sheet could also include a sticker for extra insulation on top of the Ethernet and USB connectors
Quote:Personally, I woudl be happy to lose the "seatalk" connection and gain a proper NMEA2000 plug, so I can connect with standard cables, but this is a minor point. I will have to find an NMEA2000 to bare wires cable.
There are several reasons we decided do go with a screw terminal for NMEA 2000:
1. Size: Compatible connectors occupy an area of 20x15mm on the PCB and are 17 mm high, compared to 8x7x7 mm for the screw terminal
2. Versatility: While NMEA 2000 is just CAN, some vendors have gone with different connectors for their own implementation (for example SeaTalkNG and Simnet). Plus the screw terminal is easier to use for DIY CAN projects.
3. Cost: The connector required for NMEA2000 is relatively expensive ($8-$10 in 100 quantity)
Quote:Last question: where can I buy the IMU seen in the manual?
I will leave that question to Sailoog.