BlinkenBone - hardware components

Parent Category: Projects Category: BlinkenBone physical panels Written by Administrator

A simple BlinkenBone system consists of these hardware components:

blinkenbone components labeled

 

BeagleBone

The "BeagleBone" is a credit card sized single board computer with Linux operating system. See the offical website or my own description for more.

beaglebone top

BlinkenBoard: the I/O adapter

The BlinkenBoard I/O board drives and senses the signal wires of the ancient Blinkenlight console panels.
It is connected to the BeagleBone over the BlinkenBus.
There is no fixed relationship between panels and BlinkenBoards:

The current BlinkenBoard model has 11 8 bit outputs and 5 8 bit inputs, so it can drive 88 digital outputs and sense 40 digital inputs. The weird ration of input:output = 5:11 was choosen after evaluating a handful of real panels: Typically there are more lamps than switches. While this is statistically the best choice, for every actual panel it is quite suboptimal.

Other types of BlinkenBoards are possible, they can contain a maximum of 15 input and 15 output register chips.

blinkenbone blinkenboard v2.jpg

Major features are:

BlinkenBus

The BlinkenBus is the signal connection between BeagleBone and up to 32 BlinkenBoards.
The communication is hierarchically: BeagleBone is the only master, the BlinkenBoards are all passive.
It is a parallel bus, running over 40 pin flat cable. It carries 9 address wires, 8 data wires, a read/write signal and a "strobe" to activate accesses. All signals are separated by ground wires, finally there is 3.3 V on the bus.

A flexible connection between BlinkenBoards is very important. Any rigid board interconnection would make it difficult to mount BeagleBone and BlinkenBoards into a given vintage panel assembly.

Why flat cable? We discussed SPI and I2C busses as alternatives, but flat cable is fast and cheap and runs over quit long distances in noisy environments. And if you work a few years with vintage DEC computers, using 40 pol BERG terminated flat cable seems so naturally!

See the "BlinkenBus specs" file in the attachement.

BlinkenCape: the BeagleBone adapter to BlinkenBus and RS232

The BeagleBone has two rows of board connectors with together 92 pins, there you can plug add-on boards in. These boards for the BeagleBone must have well defined electrical and mechanical dimensions and are called "capes".

blinkenbone cape

blinkenbone blinkenboard bottom

There are four function areas on the BlinkenCape:

 

Backstage impressions

Finally, let's take a look into our hardware lab:

blinkenbone hardware lab

 

Attachments:
Download this file (BlinkenBoard_schematic.pdf)BlinkenBoard_schematic.pdf[Schematic diagram for the BlinkenBoard]827 kB
Download this file (blinkenbus_04.pdf)blinkenbus_04.pdf[BlinkenBus timing specifications]131 kB
Download this file (BlinkenCape_schematic.pdf)BlinkenCape_schematic.pdf[Schematic diagram for the BlinkenCape]153 kB