Tower Bus
The physical bus is comprised of a small passive PCB backplane which acts as a rigid flying bus (in Eurorack terms). For prototyping this could be substituted with IDC ribbon cables even. The long edge of each card then has 2x80 (2x 2x40) pin headers:
- Address Pins: A23-A00
- Data Pins: D7-D0
- Other Pins: RW, !RESET, !IRQ, Clock
- Checkerboard Grounds In Between Digital Signals
-
Power (+3.3V, -12V, +12V, Extra Grounds)
-
Audio Header (Optional)
- 4x1 Non-Stackable Header
- L, Ground, Ground, R
- Run wire to wire to a mixer card when using multiple audio sources
Pinout
24-pin dual row (DIL) stackable header
| Col | Row 1 | Row 0 |
|---|---|---|
| 00 | GND | A23 |
| 01 | A22 | GND |
| 02 | GND | A21 |
| 03 | A20 | GND |
| 04 | GND | A19 |
| 05 | A18 | GND |
| 06 | GND | A17 |
| 07 | A16 | GND |
| 08 | GND | A15 |
| 09 | A14 | GND |
| 10 | GND | A13 |
| 11 | A12 | GND |
| 12 | GND | A11 |
| 13 | A10 | GND |
| 14 | GND | A09 |
| 15 | A08 | GND |
| 16 | GND | A07 |
| 17 | A06 | GND |
| 18 | GND | A05 |
| 19 | A04 | GND |
| 20 | GND | A03 |
| 21 | A02 | GND |
| 22 | GND | A01 |
| 23 | A00 | GND |
| 24 | GND | D7 |
| 25 | D6 | GND |
| 26 | GND | D5 |
| 27 | D4 | GND |
| 28 | GND | D3 |
| 29 | D2 | GND |
| 30 | GND | D1 |
| 31 | D0 | GND |
| 32 | GND | RW |
| 33 | !RES | GND |
| 34 | GND | !IRQ |
| 35 | CLK | GND |
| 36 | GND | GND |
| 37 | +3.3V | +3.3V |
| 38 | -12V | GND |
| 39 | GND | +12V |
Audio Pinout
4-pin SIL non-stackable header (will use cables)
| Row 3 | Row 2 | Row 1 | Row 0 |
|---|---|---|---|
| L | GND | GND | R |
References
- https://resources.altium.com/p/complete-guide-to-selecting-board-to-board-connectors
- https://www.lcsc.com/product-detail/C41432069.html?spm=wm.fly.bg.0.xh&lcsc_vid=QVJbAVBRTlVYUAEEFlJWVlVTFVkLXl1VRFJYVQcHRVMxVlNeRFJYUFVSTlFaUzsOAxUeFF5JWBYZEEoKFBINSQcJGk4eFQsCAgIaSgADAwAHC0slQlJdVFBXTk8GEwkK