On 05/03/2020 02:23 PM, Jeffrey Walton wrote:
On Sun, May 3, 2020 at 12:59 PM Richard Owlett <[email protected]> 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
