Adafruit PiTFT

Is it possible to use a diminutive display, such as the Adafruit PiTFT, with a Pi running RISC OS?

Do yo mean the same I use for my “HandPi”?

https://www.riscosopen.org/forum/forums/5/topics/2543#posts-32056

I think not at this time.

Rick’s written a RISC OS driver for a small OLED display as stated at the top of the posting Raik has linked to. p.s. We have them ‘in stock’ http://www.cjemicros.co.uk/micros/individual/newprodpages/prodinfo.php?prodcode=RPI-09OLED

Thanks Chris, but I’m looking for a display with specs closer to the PiTFT, or better.

Chris – I’ve not updated my index, and some people say my site navigation is a bit of a mess (it has “evolved” over 16 odd years, so think of a bramble thicket).

Anyway – probably better to point people directly to source: http://www.heyrick.co.uk/software/oled/

(Oh, and the module is EUPL so one can play with the code if they’re so inclined)

The TFT needs a high speed SPI connection, probably best done via a driver module because the Pi hardware has SPI capabilities, probably better than bit bashing the GPIO pins.

(dupe, yay for fringe WiFi in the garden)

Thanks Chris, but I’m looking for a display with specs closer to the PiTFT, or better.

I’m surprised no one is looking at the MIPI DSI output and something like this style of display unit.

Presumably it is just a matter of telling the Pi that the MIPI DSI interface is the active display (unless RO overrides what the boot code selects)
If so I suspect Rick will find a scrap device with a MIPI display pretty quickly

In the same vein, CJE would be looking for a MIPI to LDVS chip on a custom compute IO board instead of a twin chip converter.

If so I suspect Rick will find a scrap device with a MIPI display pretty quickly

Unlikely. Looks like an iPhone 4G display can be had for around €30 on eBay – the problem is that the display’s wiring is different to the Pi’s, and we might need a datasheets to figure out. Plus, we would need a datasheet to know the data format to send to the display, plus that will need GPU help. Many barriers.

bq.Looks like an iPhone 4G display can be had for around €30 on eBay – the problem is that the display’s wiring is different to the Pi’s, and we might need a datasheets to figure out.

Something along the lines of the pinout information here as a starter?.

Edit. And this

That is driving the display directly. Is it MIPI? What sort of protocol (it looks like MIPI supports various)? How to tell the GPU about this?

I think a Pi case like mine with a built in ~4-5" display would be pretty cool (extra points if it is a touch panel). I’ll need to keep an eye on the Linux side. Once they’ve done it, a way ought to exist for RISC OS. For now, all I can seem to find is a lot of forum posts asking if it is possible, and all coming to a screeching halt when they realise that the GPU is implicated.

Of course, the obvious question is – there is an LCD port. What is supposed to be connected to it? I know the Pi Foundation have made a camera. Did they ever make an LCD module?

(it looks like MIPI supports various)

TI doing a de-mystify
According to many complaints around (and the MIPI standards site you need to join the club to get the info, but it may have escaped

In the same vein, CJE would be looking for a MIPI to LDVS chip on a custom compute IO board instead of a twin chip converter.

Unless I’ve misunderstood a lot of things there are a few problems with this approach.
Displays attached to the Pi’s DSI need specific support added to start.elf.
The foundation have added support for the display they are about to launch and told me they expect to add support for another larger display next year. i.e. 15.6" 1366×768 may never appear let alone the myriad of other displays we’d like to support.
My proposed solution using a single chip HDMI – LVDS interface would have a very much larger market open to it. I could even dream of an OMAP chip on a SODIMM (Yes it almost certainly wouldn’t be Compute Module compatible)

need to join the club to get the info, but it may have escaped

I can sort of understand the need for manufacturers to keep important commercial secrets of their own innovations under lock and key, but it should be required that an interconnection standard such as that be published. By all means, charge $$$$ for type approval and such, just make the specification available.
Where do you think we’d have been in the ’80s if all the bits of home micros were hidden away under NDAs and such? Such things are offensive to common sense, so kudos to TI for some really detailed datasheets.

I’m still hoping for a slightly more detailed datasheet from Broadcom some day. You know, when they wake up and realise that that crappy old CPU+GPU chip is actually doing pretty well, and it is in the hands of a bunch of people a little more technically inclined than those who, for example, receive a home ADSL router, plug it in, and never change the default password…

My proposed solution using a single chip HDMI – LVDS interface

Info out on the net suggests that single chip doesn’t exist, dual chip is common.

I could even dream of an OMAP chip on a SODIMM

or a HAL based port for iMX6 as in the Sabre Lite board giving you LDVS and HDMI as well as MIPI DSI and SATA and 1Gb/s Ethernet (seemingly NOT on the USB) and…

I could even dream of an OMAP chip on a SODIMM (Yes it almost certainly wouldn’t be Compute Module compatible)

No need to dream.

http://www.variscite.com/products/system-on-module-som/cortex-a9/var-som-om44-cpu-ti-omap-4-omap4460

There are tons of OMAP system on modules (and probably tons of iMX6 ones as well), all you need to do is look for them. There’s even this bunch which all use different SoCs but are pin-compatible with each other: http://www.phytec.com/products/system-on-modules/phycard/

There are tons of OMAP system on modules (and probably tons of iMX6 ones as well)

So much so that you can be picky and only use UK suppliers and even be picky there. The phycard does have the enticing aspect that they look to be building a progression and future modules are likely to have pin compatibility with the carrier board of current products.

Mind you, as you’ve pointed out before it doesn’t make much difference unless the code fairies turn up with a suitable HAL etc.

No need to dream.
http://www.variscite.com/products/system-on-module-som/cortex-a9/var-som-om44-cpu-ti-omap-4-omap4460

Very interesting! If only I had the resources to do something with one of them! May be once we’ve got our Pi Compute module systems flowing they could help release some of the necessary resources. Though I’m not sure about that as time is still likely to be in very short supply!

Info out on the net suggests that single chip doesn’t exist, dual chip is common.

We have two different single chip HDMI-LVDS boards ‘in stock’¹. Two chip solutions seem to add significant complications and the extra real estate would be an added problem, so I’d prefer to avoid them if at all possible.

¹ e.g. www.ebay.co.uk/itm/111387495947 not one of the boards we have but I’m pretty sure it uses the same chip that we were demonstrating at the Midlands show.

1 e.g. www.ebay.co.uk/itm/111387495947 not one of the boards we have but I’m pretty sure it uses the same chip that we were demonstrating at the Midlands show.

The picture referenced, like the board in use at the Kenilworth show, has more than one chip. Provided I restrict the count to devices with more than 4 pins I count 4 devices.