Assignment
- group assignment
- use the test equipment in your lab to observe the operation of an embedded microcontroller
- individual assignment
- use an EDA tool to design an embedded microcontroller system using parts from the inventory, check its design rules for fabrication, and simulate its operation
- extra credit
- try another design workflow
- design a case
Something useful for the final project
As previously mentioned in my first week's post, I'm planning to make a version of Memex by reimagining the modern web browser experience with low tech. One of the key components is the scrolling mechanism, which I'm imagining to use a trackball device to control the scrolling. After some googling on the optical sensor for the trackball (I've thought about purely mechanical solutions like a wheel or a ball, but this part of the class is about electronics so here we are), I found the PixArt PMW3360 sensor.
PixArt PMW3360
PixArt PMW3360 is an optical mouse sensor found in many mice and trackballs. Here's the datasheet for the PixArt PMW3360 sensor. On page 8, it seems that the sensor comes with a chip and a lens, but the customer will have to supply their own breakout PCB and base plate for the lens.
There are a few vendors that sell the sensor with their own breakout PCB, for example Joe's Sensors and Sundry on LECTRONZ.com. Although I'll probably opt for a bare sensor from AliExperess, in the spirite of the class, I do appreciate their open source effort in designing the breakout PCB. I also stumbled upon a few other open source PCD designs, such as this one by kbjunky, and this one by jfedor2 (specifically for the RP2040).
These open source designs saved me a lot of time reading the datasheet and understanding the sensor.
I also found a symbol and footprint for the sensor on SnapMagic created by trimenz. After eyeballing the footprint against the datasheet, the schematic is missing some pins for reason I don't know. So I'm not using it.
KiCad
Because of my limited experience (all of my experience is limited to Quentin's recitation), I decided to take a look at jfedor2's kicad project file.
The schematics has quite a some parts - flash, crystal, GPIO pins breakout, etc. I'm not sure exactly what they do yet. My plan is to modify this open source schematic to fit my XIAO RP2040 board.
TO BE ADDED.
