German maker Matthias “bitluni” Balwierz has proven off one other of his customized application-specific built-in circuit (ASIC) designs from the newest Tiny Tapeout manufacturing run: a devoted controller for a persistence-of-vision (POV) show.
“I made a lightsaber 5 years in the past that used [a] gyroscope and NeoPixels to show pictures in mid-air,” Balwierz explains of the inspiration behind his mission, one in all three submitted to Tiny Tapeout 2. “I believed this additionally could be potential with the kilohertz clock of Tiny Tapeout 2, so the plan was to make a easy controller that may have the ability to show graphics or textual content on a rotating fan or one thing.”
Matt Venn’s Tiny Tapeout mission provides a method for makers to create customized silicon chips, one thing that may usually price tens of 1000’s of {dollars}, simply and cheaply — by splitting every chip up into a number of mission tiles. Balwierz submitted three tasks to Tiny Tapeout 2, the second manufacturing run, together with one which was claimed to be the primary Rickroll on a chip.
This second mission is considerably extra sensible. Working across the restrictions of a Tiny Tapeout mission, which place higher limits on clock pace, inputs and outputs, and total design footprint, Balwierz made a controller able to driving an eight-LED POV show. “The issue was,” the maker explains,” within the restricted area of a tile on Tiny Tapeout 2 I used to be solely in a position to slot in about 20 to 30 columns of pixels; that decision isn’t excessive sufficient to jot down any textual content and the graphics could be fundamental at finest.”
The controller drives eight LEDs, delivering textual content and restricted graphics from an on-board character ROM. (📷: bitluni)
“So,” Balwierz continues, “within the third try I made a decision to mix a hard and fast character set and graphics. I used to be capable of match 30 phrases of seven bits; the best vital bit would resolve if the phrase represents a column of pixels or an entire character of eight by eight pixels from a personality ROM that is on the ASIC itself. [This] ended up being the capital letters, digits, and a few commonly-used particular characters.”
The completed mission, which is demonstrated on Balwierz’ YouTube channel and within the video embedded above, is able to delivering a 240×8 show; extra data is offered on the Tiny Tapeout web site, with supply code printed to GitHub beneath the permissive Apache 2.0 license.