Projects/Bitsy
Now that we’ve our first prototype, let’s figure out how to flash the sucker!
The MK22FN512VLH12 has 512KB of on-board flash where a program can be stored. The process of writing a program to this memory is called flash programming.
There’s several suggested ways to program the flash on the MCU. For development, the SWD or JTAG is preferred since it’s main purpose is for debugging. Troubleshooting this interface can be a bit messy though… it’s quite complex. Read More...
The most challenging IC that I’ve solder was a LT3463 booster converter that came in a 0.5mm-pitch 10-pin DFN package. Instead of pins, QFNs/DFNs have pads on the bottom so it’s a bit challenging to solder, inspect and de-bridge.
Thankfully, the MK22FN512VLH12 comes in a QFP package - pins instead of pads! This package also has a 0.5mm pitch but with a lot more pins (64 to be exact) - which means a lot more opportunities for solder bridges - fun! Read More...
Since this project involves many firsts for me, I decided to keep the features at the minimal bar - this means no USB OTG, no properly filtered analog references, no RTC. One goal however is to reach 120 MHz which means we’ll need a crystal!
Here’s a render of the final board sent to OSH Park:
Tips from Teensy 3.1 The Teensy isn’t open-hardware/open-source but it does have some rough schematics that proved extremely helpful. Read More...
For the last year or so, I’ve been using a Teensy 3.1 from PJRC to power one of my projects. I quickly graduated from using the Teensyduino to using pure C. It has been, by far, my deepest dive into the world of ARM MCUs - and we’re about to go deeper!
The Teensy I chose the Teensy 3.1 because I needed a cheap, easy to use, yet capable, MCU dev board that I could rapidly prototype with but also as a reference design if I ever dreamt to go to production. Read More...