Mario gave Samuel a few raw Optelec braille cells. These used to be covered by patent 4,758,165, but it is now expired.
The patent mostly covers the mechanical part with the piezo bars, it doesn't describe the electronic part. Fortunately, the electronic part is extremely simple:
An 8-bit two-stage shift register chip (aka serial/parallel converter), on some cells it's F4064 C0614, on others it's F4094BT 863530D HSS 9314 P3. In any case, it seems like it is a very common chip, it's easy to find documentation for several variants: CD4094BC documentation, HEF4094BN documentation, thus the pinout.
- A few transistors and resistors.
There are 7 external pins, one alone at the top, and 6 grouped together below, which are here numbered from 0 to 6 starting from the top:
- 0: Piezo red wire, probably positive high-voltage (alone at the top)
- 1: Piezo black wire and chip Vcc
- 2: Probably bound to the chip, but it's hard to follow where exactly as the track goes under the chip
- 3: Chip Data pin
- 4: Chip Clock pin
- 5: Chip Strobe pin (i.e. update the cell dots according to the current value of the shift register)
- 6: Chip Vc0 pin
It should thus be fairly straightforward to at least make a couple of test with those.