QProbe2023 - Building the kit
Some hints for kit-builder:
QProbe
Nothing special here!
Before soldering the two 2x20 IDC connectors, you may pull off one makred pin on each.
Then you can later add a key-peg to the flat cable connectors, against mismatches.
The CPLDS can be programmed by you, see previous pages.
About LEDs in general
LED colors and brightness make a big difference in the "lock&feel".
Its not so easy to achive "retro light" with modern LEDs:
In the old days LEDs were very red and quite dim.
White lamps were made of light bulbs, often run under-powered, so they also had a warm white.
Todays LED in contrary outperform each other in "super-brightness".
I found even different batches of the same LED-type to get enhanced in brightness... apparently its common sense: "the brigther the better".
Especially the warm-white LEDs used here are this efficient, they need series resistors of 10K at 3.3V supply voltage, else they burn out your eyes.
Thats the reason I use sockets for all LEDs, to adapt to changes in LED brightness.
LED-Plug
The LED-plug is straight-forward.
It consists of two parts. The upper label-panel should hold "click" onto the 1.8 mm LEDs without further fasteners.
LED orientation is:
While soldering, push the label-panel onto the LED repeatedly, to guard against major mismatches.
The two long-distance socket blocks is soldered last. Align it with another QBUS card to make sure "LED-plug" hovers over its neighbors.
DriveBay Panel
The DriveBay-Panel is a complex sandwich construction.
The distance between base PCB and "label-panel" is dictated by the switches. The LEDs have to adapt.
Here soldering order is important.
- Solder the IDC connector and the resistor (sockets) to the back side first.
2. Mount the four distance bolts to the upper label-panel, with black screws.
3. Solder the LEDs.
They need to be soldered with "long legs", to the height of the upper label-panel. There is a 3D-printed alignment tool, which helps to solder upright and in right distance:
If you are right-hander, work the rows from left to right, and from "most away" toward you. Solder only one leg at first, and repeatly plug the upper label-panel onto your work for checkout.
To align the LEDs, mount the top panel over the LEDs after each row (or even after each half-row).
Solder the 2nd LED of each LED, then re-heat the 1st leg, to let tensions go.
4. Place the 7 switches. Make sure the one "momentary" switch is correctly orientated.
5. Finally mount the upper label-panel, then solder the switches .
6. IF the resistor packs are socketed, populate the sockets last.
Resistor packs are 2x4, but one is 2x5. You can populate a 2x4 there and plug a discrete 10K to the remaining socket holes.
Also solder the single 100K for 12V LED last from the backside.
7. Test: plug the panel to the QProbe, add termination resistors on QProbe, power the QProbe with 5V, set the MODE switches to 0011,
and touch each QBUs signal with a GND probe. The corresponding LED should shine, ADR and DATA are coupled pairs here.