As a data logger you can get A/D converter boards under $10 for a Pi GPIO. On May 3, 2020 1:23 PM, wrote:
I'd go with a Pi 3, 7 inch touchscreen, and 3 - 10 18650 lithium cells. You can get little switch mode voltage regulators on Aliexpress or eBay for a couple bucks. When you're not using it as a portable you've got 4 USB jacks, WiFi, Bluetooth, CAT5 ethernet., HDMI. Not sure about Debian drivers for the display, they come with Raspbian (almost the same). On May 3, 2020 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). Suggestions for suitable selection guides? TIA