The mini calculator ELLO LC1 is as flat as a credit card and still offers an integrated LC display.
On the Hackaday website, hobbyist Kn/vD presented a tiny 8-bit computer that is extremely compact and as flat as a credit card. Nevertheless, there is space for an LC display and a keyboard on the mini computer called Ello LC1. To do this, the components had to be extremely flat. Some components are even sunk into the circuit board, while all soldering points are on the back of the circuit board.
Sunken display and touch keyboard
Despite this, the hobbyist added a keyboard with 48 touch-sensitive keys to his minicomputer. The LC display, on the other hand, can show 20 characters in four lines. In order to save thickness here as well, the display was sunk into the circuit board, as was the button cell for the power supply.
Basic with file manager
A PIC18 8-bit microcontroller is used as the CPU, which is supported by 13 KB RAM and 128 KB flash memory. However, only 64 KB of the latter can be used by the owner. Programmers should also be happy about a 12-pin header that can be used for debugging and GPIO extensions. Kn/vD also created a suitable basic system for the 8-bit computer called Bitling Basic. It’s very minimalistic, but it only uses 2 KB of the scarce memory. Nevertheless, there is a file manager and a text editor in the software. The hobbyist wants to publish the code for his project on Github shortly. Hackaday website. There you can also find a blueprint that shows the control of the keyboard and the pin header.