In this section you will find not really necessary stuff related to the Vital Sign Simulator, or things which are for andvanced users only.
Dedicated control panel for the trainees
As a alternative to the simple modified keyboard, you can build a more serious-looking dedicated control panel.
- USB-Keyboard (will be taken apart and no longer usable for other purposes)
- Some wires (preferably different colors)
- 12 Electric push-buttons
- Casing of some kind or 3d-printer to print my model from Thingiverse
- Soldering equipment
- Hot glue gun
Open your keyboard, but don’t break anything. Inside you should find two or three plastic sheets, clamped to a small electronic unit, which is connected to the USB-cable.
Take out the electronic unit, don’t break the connection to the USB-cable.
Look at the unit. You should see a row of connectors where the plastic sheets were connected to the unit. Usually there are two groups of connectors (in my case group A = 12 connectors from the left and B = 14 from the right. I had to do some tests to find out, see step 8).
The keyboard works like this: If you press a key, you create a circuit from group A to group B. Depending on which connectors are connected, a signal representing the character is sent to your PC (eg. in my case if connector A03 and B07 are connected, the character “x” appears on the screen). In theory there are 168 possible combinations.
Now for the difficult part: You have to solder a short wire to each connector. Usually the connector is coated with a conductive rubbery substance which doesn’t solder well. Scrape it off and solder the wires to the copper part beneath it. Be careful not to solder a bridge between connectors, they are usually placed very close to each other.
Use lots of hot glue to protect your solderpoints as they tend to be not very stable (see picture).
Use screw-terminals to bring some kind of order into the wires (see picture). You might want to put numbers on them.
Draw a table with group A as colums and group B as lines.
Open this online keyboard-tester or a similar application. Then one by one connect each connector from group A to each from group B and note the corresponding key on your table. Now you know which two terminals to connect to send the “ENTER”-signal (= shock for VSS) for example. In my case A04 and B10.
Solder two short wires to every push-button and place them in the casing. Colored wires might help.
Now connect the wires from the push-buttons to the appropriate terminals. E.g. in my case the button which will be the “SHOCK”-buton goes on terminal A04 and B10 (= “ENTER”). Repeat this for every button.
- Energy up: END
- Energy down: DELETE
- Load: BACKSPACE
- Shock: ENTER
- Analyse: SHIFT R
- Sync: UP
- NIBP start: SPACE
- Pacer on: ZERO (Numpad)
- Rate up: 9 (Numpad)
- Rate down: 8 (Numpad)
- Current up: 3 (Numpad)
- Current down: 2 (Numpad)
Connect the thing to your PC and test it. If every button works as it should, stuff everything inside the casing and close it. If you use my 3d-printed casing, there is a clamp to secure the USB-cable.
Create a descriptive overlay or something similar to put on the top side of the control panel. You might also put stickers on the buttons themselves.
I used a graphic (see below), printed on a normal sheet of paper, and laminated it in an adhesive laminating pouch. Then I cut holes in it where the buttons go through. The stickers for the buttons (arrows, flash) were printed on the same piece of paper. Please note that in my case the overlay is labeled in German 😉 .