EDIT² : I updated the BOM at bottom of this post.
The title says it all guys 
Btw I realize this is my first thread ! It’s time I started moving my lazy ass.
I need a reliable yet very flat & compact switch button for my skates so most mechanical buttons can’t work for me. I simply don’t have the space for the cylindrical body and toggle switch is out of question ! And I’d like to make a custom button shape and material with RGB LED for a sexy finish. Momentary push-type is sleek.
I already got a vedder-type anti-spark module from @goldenHusky, what I only miss is really the switch itself to command the module.
So… I’ve been itching to build a soft-latching single button switch instead. If you look around, you’ll find tutorials with different methods to achieve that - first example :
Please note that this example have the drawback of starting in “ON” position and not “OFF” yet we do want the switch to always start disconnected. So we’d need an auto-reset function included to guarantee that.
Edit : we also want a delay function (push ON / hold 2-3seconds OFF) !
Well there are good news : @s28400 has done the hard work to make an auto-reset soft-latching switch interface with Vedder’s anti-spark module ! There is no update on the matter since September 2016 and no BOM posted but as shown below it was already working back then with all wanted features :
Posted from his page “radical-creation” :
The best solution I have found is a soft latching switch circuit. This utilizes a momentary switch to latch a logic signal high or low. A slightly modified version of this circuit will yield a push on and hold off configuration. This is ideal because it is the most reliable and most robust of all the options.
I put together a quick circuit on a breadboard and interfaced it with a mosfet. I will post a full schematic once I finish it. Anyway here is a video of the working circuit.
It seems to work perfectly and I will next look to reduce the size of the circuit by making it on perforated board and possibly a custom pcb.
So what we lack is a PCB with a BOM. Can you help me source proper parts to try this out ? We can make a great low-profile custom switch to plug on our anti-park modules thanks to Joshua’s work.
Here is the schematic :
Proposed BOM (work in progress) :
- 1x Linear regulator : LM317HVT (60v max input, programmable output to 5v - need a pair of resistors or potentiometer to fix 5v output - good up to 12s/13s) or 1x LM7805 linear regulator (40V max input, fixed 5v output - no resistor needed - good up to 8S)
- 2x 100kOhm resistors
- 1x 5mOhm resistor
- 2x 1uF capacitor (from the bucket)
- 1x 1mOhm resistor
- 1x heatsink for the regulator
- 1x NAND gate (5v) - I went for CD4011 chips, cheap 4x NAND available on eBay
- 1x MT3608 boost converter or 1x LM2596S step-up converter for excitation of “C” pin
- 1x 12v zener diode
- 1x irf510 mosfet
- 1x momentary push button (you can either get a mechanical one or recycle one from a TV remote)
Optional (for some custom) :
- 1x simple LED or the combo
- 1x ws2812/sk6812 RGB LED or more
- 1x arduino (Nano or else)
- 1x 470ohm resistor
- 1x 1000uF capacitor
Next step (work incoming) :
- The wiring !
