Handheld BASIC Computer in Badge Format with the Arduino Uno

Since the new 32-bit Arduino UNO R4 has arrived, it's time to make a glorious farewell project for the classic 8-bit UNO R3! Clem's idea is to use all of the pins and turn it into a handheld BASIC computer, similar to a Sinclair ZX81 from the 1980s.

This computer badge will use up all of the available pins and show that an 8-bit microcontroller is, in fact, a tiny computer. The badge form factor also makes it ideal for your next meetups with fellow makers.

#0:00 Welcome to element14 presents
#0:32 Overview
#1:19 Design
#4:15 The PCBs
#7:01 Programming
#8:57 Problem Solving
#12:15 The Keyboard
#15:48 The Case
#17:04 The Computer Badge!
#20:21 Give Your Feedback

#sinclairzxspectrum #zx81 #arduino #arduinoproject #arduinoprojects #arduinoprogramming #pcbdesigning #pcbdesign

[Certawin]

Neat work Clem. Cool that you got it working. Even with all your hurdles that you had to jump. And enjoy your basic badge. :)

[dimitrioskalfakis]

nice effort. even with a limited hardware and initial design choices set in stone the software is always the key factor in the usefulness of the machine.

[ddjazz]

Great video, thank you for also including the mistakes and frustrations you encountered, it comes with the territory :D

[tractorboy]

A surprisingly addictive video with a great result. Well done with all the 3D-printing on top of all the other challenges. Happy conferencing!

[andywest]

Great project! I have a fondness for computers with ROM BASIC, since that's what I grew up with.

[bald_engineer]

14:14 Interestingly, to me anwyay, the reason the ZX-80 and 81 do the "BASIC shortcuts" is because you are tokenizing the command as you type. Other 8-bit computers processed the text string "PRINT" and converted it to a token. However, to save space in their tiny ROMs, Sinclair made the user do the tokenization.

[retrojon_]

A possible add-on that comes to mind is some sort of paper tape reader. The reader wouldn't have to be too big (especially if it's hand-operated and doesn't need motors) also, the tape can be very compact once rolled so it would be easy to carry prewritten programs, load them, and run them! I'm gonna have to dig out my Arduino and try something similar soon!

[FedExk]

Yes diffidently do more with this computer! Maybe possible upgrades, addons and uses.

[raffyturc]

you slayed it dude! nice effort!
yeah there are some gotchas in the SMD(?) like complete C-port (adc6 adc7). and also the 'DAC' on AN0 w/c doesnt work(?). and also, practice more on your soldering skills 😅. cheers!

[DTechnic-]

u should build a label printer like that as that would also have a practical use

[wimletzer]

Nice little computer! You asked for possible extensions. Well, I would like to see a micro sd slot, to save programs. I think there's space for in the arduino not running basic.

[MAYERMAKES]

There is the possibility of adding Extras to this little handheld computer! what should we add to it, a floppy drive? or something even more crazy! what are your ideas?

[AjinkyaMahajan]

i think a composit video TV out is also possible in 2nd atmega chip making it an actual z80 machine
Cheers!!

[dennisolsson]

Too late, but: you could run the display in 4 bit mode to free up 4 pins.

[darrellbeta]

CAD files download goes to a page not found page!!

[amsmuh]

Why not use a line with a series of resistors and a ADC for reading the keys?