Rev 3 PCB

A project log for No-Eye Haptic Clock

Gone are the days of waking up in the night, forcing your eyes open to check the time, and then blinding yourself with your phone backlight!

Michael KafarowskiMichael Kafarowski 09/04/2019 at 00:010 Comments

With revision 0.2 came some victories and some defeats. The audio system "worked", although the quality was quite bad. I chose an i2c flash and DAC chip, not realizing that the speed of that protocol was much too low for audio (<400kbps). I had to downsample my already low 8khz bandwidth audio track to <4khz, which resulted in a lot of distortion. To address this, I’ve chosen new parts, each now using SPI. As a matter of fact, the flash chip was the wrong choice anyway because it was a 3.3V part and my board runs on 5V. Oops. 

I redesigned the whole board with smaller footprints, replacing the 1206 passives with 0603 for more flexibility and reduced size. 

I also dropped the circular form factor for now, as it was an inefficient use of space. Once I finalize the circuit, I’ll decide on a final form factor and do a more thorough route.

I've sent the board to fab, and it should be in some time next week.

The project’s Github repo is now public! Check it out here: