Category Archives: Tommy System

Just Another Tommy Schematic Update #4

To add more functionality to the Propeller an ATMega168 was added to the design. The Propeller communicates via I2C (on the same bus as the EEPROMS) to the ATMega168. The ATMega168’s function is to provide dedicated servo control and analog input for the propeller. Since servos have to constantly PWM controlled the Propeller has to dedicated an entire cog to just maintain servos. Using the ATMega168 to off load this tasks frees up lot of resources for the Propeller which will allow for better animations and smoother kernel cycles.

Tommy System Schematic Update #2

I fixed the EEPROM addressing issue. Since the EEPROMs are addressed via I2C protocol you have to set there addresses via the pins A0, A1, A2. Previously I had these all to VSS or GND which would mean all there addresses where 000.

Added the SD Card to the Parallax Propeller to store audio files. Took longer then expected to make the footprint and get the part correct in eagle.

Power will come into the board via 4-Pin Molex connectors much like on a PC power supply.

Currently have TLC5940 16 channel LED drivers on the board but these will be changed to WS2803 Chips as they use 3 less I/O lines (5 vs 2). These will be used exclusively for RGB LED lighting. I am planning on being able to hook up 18 RGB LEDs to the board.

Tommy System Specifications

Here are the loose specs for the Tommy System.

  • Parallax Propeller running at standard 80Mhz. Can be overclocked to 100Mhz.
  • Three SD cards. Music, sound effects, bitmaps for animations.
  • Two Stereo sound channels. Plays PCM WAV files.
  • 64 Bits of Input.
  • 64 Bits of Output. Can be divided between solenoid/motor control and light control and way. Standard will be 24 bits of solenoid/motor control and 40 bits of light.
  • General Illumination via RGB LEDs built in.
  • Compatible with 96×16 DMD and 128×32 DMD (only in 1 bit mode).

The goal is to keep this low cost.

Pinball Homebrew Platform: Tommy

I have had lots of requests for people wanting the hardware and PCBs for Reset Vector. I will be designing a pinball homebrew platform named Tommy. Key goals will be keeping cost down and complexity of the circuit down so it will be easy to build on .1″ perf board. Will be all through hole parts. Support for the 128×32 Display built in. Goal is to get the PCBs down to $15 a piece.