This week was dedicated to making solid progress on the PCB. We wanted to get the parts ideally by this week as the order was placed last week. Ideally, we wanted to have an initial prototype done on the breadboard this week to use as input to the PCB before sending it off. As I worked through the PCB schematic, I realized that the number of GPIO pins might be a limiting factor to the pedal surface I/O that we had. Hence, we reduced the number of pitch shifting buttons from 4 to 2. Originally, we had 2 buttons for +/-1 octave and +/-1 semitone pitch shifting. I decided to remove the +/-1 octave buttons to free up some GPIO pins. After discussing with Nick, he also looked into 7-segment displays with potentially less pins. He found a 12-pin display that I downloaded an updated my schematic with. I was able to go through the datasheet for each component and figure out which pins corresponded to what functionality. After doing so, I was able to make the appropriate connections to the Daisy Seed microcontroller. I was able to get the schematic done for the pitch adjustment buttons, mode switch, and beat/pitch LED buttons rotary encoders, and ON/OFF LED. I also realized that I needed pull-up and pull-down resistors to make sure that I was sending good 1’s and 0’s. I added these in, adding 10kOhm resistors going into the GPIO pins and 10kOhm resistors for switch pins that were not ON. Please see the my current schematic progress:
I think my progress is back on track. I had doubts last week given my unfamiliarity with KiCad, but I spent a lot of time this week watching tutorials and reading the datasheets multiple times to get a solid understanding of the hookups. After getting most of the schematic done, I am more confident in the timeline to get the PCB out.
I still have to quickly do the hookups for the 7-segment display and 2-mode switch for selecting 3 vs. 4 beats. I have already looked through the datasheets to verify that the parts are good and that I have a solid understanding of the pins in the schematic. My next steps are to clarify some of the datasheet pinouts to make sure my hookups are correct. I will set up a time with Gordon early next week and finalize the schematic shortly after. Once this is done, I need to quickly place and route in the layout view and use Gordan’s help to get the PCB out as soon as possible. Hopefully, by the end of next week, I should have a nearly complete layout that can be sent out.