How do we interface to and/or control the Pi-Top HUB? . . . does anybody have the specifications of how to interact with the HUB to control Pi-Top functionality (screen on/off & brightness), sense the Power Down event and monitor battery charge ?
This seems like critical/important information that the Pi-Top team need to provide !
I think that if the pi-top team want to embrace the spirit of the "Raspberry Pi's" open architecture, then they would publish the schematics of the HUB and fully disclose it's functionality. If and when they do this they will not only be more popular with the Open Source Community, but they will be given excellent suggestions by the public and open engineering community as a whole that will enable them to continue to improve the reliability, and functionality of the pi-top. This closed source add-on to the open-source Raspberry Pi hasn't been a stellar success from what I have seen. I think they desperately need the assistance of the open engineering community.
There is an interesting video in the Ben Heck Show showing assembly of a Pi-top and developing a break out board for it. You can get at it via element14 or via pi-top's Facebook page. The breakout board is interesting because they traced the wiring of the 34 way connector under the pi-top hub and put together a board with some peripherals on it. This is exactly the sort of thing that pi-top should make available. As far as I can tell the files from the Ben Heck Show are not available yet, but hopefully will be soon.
Be warned there is an error in the diagram found on the pi-top site pin 33 on the connector is shown as connected to GPIO 20 / RPi PIN 39. should be GPIO 20 / RPi PIN 38. RPi PIN 39 is a GND
What Raspberry-Pi GPIO's are used by the pi-hub?
I have a new CEED, and from what I can tell, something about the CEED is stomping on MISO even when SPI channel 0 is being used. With my old configuration (a Pi 3 B with nothing on the GPIO except my device), it works just fine.
Has anyone gotten SPI working on an independent device with a CEED?
you can find the diagram under support - build on the pi-top site
Does anyone have a product listing for the connector? I know it's a 34 pin (17x2) 2mm pitch, but I'm having trouble sourcing one.
Are there plans to sell modules such as a breadboard that will interface with the plug on the side of the pi-top hub? I too have looked for an adapter like the one created on Ben Heck's show but have not had any luck finding anything that will work.
Which SPI chip select pin is used for the Hub? Would using another SPI peripheral work OK if it was enabled by the other chip select pin?
I've been trying for a while to get CAN BUS (MCP2515) working on SPI Bus, and like Nick Sayer, I too cannot get access to the CE0 SPI. It DOES seem like the hub was holding on to the MISO line when not necessary, I originally thought it was the cable (40 pin to special connector jumper).
I fixed this by removing PIN 8 from U200 on the HUB MK1 for the CEED, I assume I no longer have assess to brightness control, but thats cool.
***I'd like to ask the folks at PI-TOP during their next iteration of this HUB MK 1 board to change to serial connectivity for brightness, as SPI has a potential for such great speeds, you'd never utilize its potential using it for brightness control.***
If the screen refresh rate is 30HZ, why drive it with SPI 400Khz? and inadvertently killing both SPI channels?
Samtec TMMH-117-01-L-D-RA, available from Farnell, looks a suitable connector