With the completion of my laser-tag omnibot project (video of fight robots coming soon!), I’ve been kicking around ideas for my next project. I wanted to get some practice writing some longer embedded code. Being a big fan of The Ben Heck Show, I watched his recent Teensy Pinball Portable build with my 11-year old son who REALLY wanted to build our own. I know pinball machines can get $$pricey$$, but with the smaller size and limited mechanical components it seemed like a good idea. So, I’ve laid out a plan for the electronics and my son has set to work sketching ideas for the playfield and game rules.
I’m basing it closely on Ben Heck’s design, except that the coding for him was a simpler version of his previous pinball builds. I’ll be working from scratch, so it should be a decent challenge. I haven’t used the Teensy 3.1 before, but after checking out some possible Atmel ARM-based chips I decided the ready-to-go Teensy dev board was much more reasonable to start with. It uses an MK20DX256 32-bit ARM Cortex-M4 72 MHz chip, which has much more horsepower compared to the 8-bit ATMEGAs I’ve been using. Here’s a block diagram of the my electronics plans:
We’ll see how it goes. Ben Heck has the shift registers all sharing the CLK and LATCH bus, but each with their own data lines. All the packets are 16-bits, so they all get clocked in or out in one go during an interrupt.
While waiting for the Teensy 3.1, audio adapter, and other components to arrive I laid out a board for the LED driver chip, the MAX6971. I’ll have a bunch of hand soldering to do, but this was another good chance to practice making a PCB that will also save me some work later:
I’ll keep you posted! -DF
Electronic Fish 