I was talking about the original official 7 inch display from Raspberry Pi: https://www.raspberrypi.org/products/raspberry-pi-touch-display/
I have one, the resolution's not wonderful (800 x 480) but it just works. I changed from Stretch to Buster (Raspbian) with a blank SD, the display works without doing anything extra. The touchscreen is a capacitive or resistive matrix on the screen feeding an A/D converter and it works: where you touch the screen is the same as a mouse click there. Not sure about HDMI ones. This uses the DSI connector on the board, doesn't involve the GPIO or HDMI at all. They power it from 2 pins on the GPIO but you can change that, it just needs 5 volts. Or use that connection as the 5 volt input to the Pi and display both and bypass the silly microusb. BTW to emulate a Blackberry a Raspberry Pi ZeroW might be adequate. It's single core so slower but much lower power. They have been run on a single lithium cell but they complain about low voltage I think. https://www.raspberrypi.org/products/raspberry-pi-zero-w/ There's no DSI connector though. On 5/4/20, Richard Owlett <rowl...@cloud85.net> wrote: > On 05/03/2020 02:23 PM, Jeffrey Walton wrote: >> On Sun, May 3, 2020 at 12:59 PM Richard Owlett <rowl...@cloud85.net> >> wrote: >>> >>> I've been thinking about what a handheld computer COULD be. >>> My image is heavily influenced by my recollection of Palm Pilot. >>> >>> My project goals are two-fold >>> 1. create a personal data logger reminiscent of a Palm Pilot >>> 2. become familiar with Raspberry Pi while using Debian as the OS >>> >>> My needs include: >>> >2 hours battery life >>> 4" by 7" nominal form factor >>> touch screen input using a stylus >>> display will be entirely character mode (40 chars/line would be OK) >>> OS GUI not required except to say where stylus is >>> OS shall be Debian {possibly with non-free drivers} >>> >>> I've not found found user friendly selection guides. >>> A typical problem was not being able to know if a selection of >>> components had mutually compatible I/O (electrical and physical). >> >> I can't speak for others, but I once I select the RPI (usually a RPI3 >> or RPI4), head over to Amazon and look for the accessories. Cases are >> $10 to $30 USD, screens are $20 to $50 USD, etc. I've never shopped >> for a battery so I can't really say anything about them. >> >> The only tricky thing I have encountered is screens. If you want to >> keep the GPIO pins available for other work, like signals for buttons, >> then you need SPI data connection for the LCD screen. The problem is, >> SPI connectors are only available for 7" screens or above, which are >> usually larger than I need. > > The page [1] for Adafruit's 3.5" display seems to say it can use either > the GPIO connector or SPI. Determining which display worked with which > Pi was a sticking point when I pursued this last year. > [1] https://www.adafruit.com/product/2441 >> >> You might also have some trouble with a case. Most cases have openings >> for ports but not much more. If you are having trouble finding a case, >> then buy one of those inexpensive 3D printers and make your own. >> >> Jeff >> >> > > > -- ------------- No, I won't call it "climate change", do you have a "reality problem"? - AB1JX Cities are cages built to contain excess people and keep them from cluttering up nature. Impeach Impeach Impeach Impeach Impeach Impeach Impeach Impeach
