Rasberry Pis and similar are sometimes sold as credit-card sized, but they are not portable, really, have huge Ethernet ports and no display or keyboard. Those are on the too-big side for what i am looking for.
In the other hand, you could say that SIM cards or USB devices are technically computers, but they lack a user interface. They are too small.
Is there something small with a usuable display and input method; something that looks like a calculator or tiny smartphone? Does not need a battery (although that’s a plus). Does not need WiFi or 5G (although that’s plus). Needs some standard method to communicate with the outside world (USB, Bluetooth, NFC, Wifi, …). Should easily fit in a pocket, wallet, purse.
Ideally something that can run a minimal Linux or Android?
Yes, they are called phones.
Yes, a generic Android phone would do, but I was looking for something smaller and cheaper; more like a feature phone. And then i don’t need the capability to make phone calls.
In fact, I was looking to replace smartphone apps with somethings that’s not a phone. Why? Some people just don’t like phones. Some places don’t allow phones.
Unihertz makes a bunch of tiny Android phones, which are about the size of a credit card (if you ignore the thickness).
They cute
Yes, that’s the kind of hardware i was looking for. Of course, thinner would be cooler, and i could compromise on the specs…
I have a small laptop by the name of GPD WIN 2. It’s about the size of a Nintendo DS, touchscreen, keyboard, one USB-A and USB-C. Might suit your needs.
Larger than what i was looking for, but looks like a powerful and fun device.
Technically this fits your requirements…
That’s exactly what i had hoped to find. Maybe not for the first prototype, but then…
Nice use of the word “fits” :P
No linux/Android, but this is the closest I can think of. https://shop.m5stack.com/products/m5stack-cardputer-kit-w-m5stamps3
Consider the cardputer Link. It’s intended for hobbyists who are willing and able to write programs for it but the hardware is roughly what you described.
Sexy and very tempting at the price tag. For protyping that’s ideal and it demos what’s possible.