Teensy Bootloader with MK64FX512VLQ12

[vince.cimo]

Hi guys, I'm thinking about using the Teensy bootloader chip with the MK64FX512VLQ12 for a medium volume manufacturing run and had some questions about the implementation. The MK64FX512VLQ12 has 100 gpio pins. How does the Teensy software utilize those pins? How many of those pins can I do PWM (analogWrite) and how many can I do a digital read on? I've tried looking through the datasheet but get a bit lost. (https://www.nxp.com/part/MK64FX512VLQ12)

Thanks!

 

[Theremingenieur]

The Teensy core files (the so-called Teensyduino software) provide an Arduino-like and Arduino compatible API for the Teensy development boards. Thus, logically, there is only direct support for the pins brought out on the corresponding dev boards, in your case the Teensy 3.5 which is based on the MK64FX512. You are naturally free to fork the Teensyduino core files (everything is open source) from GitHub and to extend these, thus creating support for the actually unsupported GPIO pins and other functionalities which can be routed to these pins through the signal multiplexing unit of the MK64FX512.
But I fear that you won’t get around studying the complex reference manual, although studying the Teensy core source code will help you understanding how things work, too.

 

[vince.cimo]

That may be a task for rev. 2. I believe the 58 I/O pin implementation should work for my project as long as I can get good enough results using digital I/O for my LEDs and not doing fancy things like fading. (softPWM only supports 20 pins max). Otherwise I'll just have to multiplex or shift register off of the PWM capable pins, which may be better in the long run...

 

[PaulStoffregen]

Before you begin your custom PCB design, I would recommend getting a Teensy 3.5 and building a prototype on a soldless breadboard or by soldering parts on a perf board.

Regarding your questions of how many of each resource are supported, this page can probably help.

https://www.pjrc.com/teensy/techspecs.html

But no amount of reading specs can really give you the sort of understanding you'll get from actually prototyping with the real hardware on a solderless breadboard.