Sunday, October 2, 2011

Open Source Paintball Board (OSPB)

Cost of the open source paintball board...

I have been asked a time or two about the cost of the OSPB, so I thought I would do a running total of the cost. The below would be if YOU MADE YOUR OWN. If it was ever sold commercially the costs would be totally different because someone else would be doing all the work/assembly/testing!

I will try to update this post to reflect costs as they arise, but so far thats what they appear to be!

This also assumes you have the tools to assemble (so far a drill, soldering iron, laser printer)

Arduino Nano - 25.00$

2 Sided Copper Clad PCB - 4.19$ (Your gonna have alot left over!)

PCB Etchant - 10.49$ (Your gonna have alot left over!)

NPN Transistors - 0.72ea x2 = 1.44$

Voltage Regulator - 2.80$

2 Pole Connectors - 1.35ea x4 = 5.40$

4 Pole Connectors - 1.81$

6 Pole Connectors - 1.85$

TOTAL = 52.98$

Open Source Paintball Board (OSPB)


So im narrowing down board designs and wiring. Here are some of my observations so far.

Linear Voltage Regulator - This basically takes the 9v and reduces it to 5v. The excess power is given off as HEAT. This appears to be how most other PB boards operate and the main reason I suspect is price and space.. LVR's are SMALL and simple to use.Why not use the LVR included on the Arduino Nano? The nano has a LVR that can sustain 500mA, the F1 5way takes 200mA, and the sear tripper takes 1A (peak, not sustained). That means that I believe that we would overload it VERY quickly and either burn it up or just overheat it and it would turn off. If battery life is a serious issue I will look into a Switching Voltage Regulator as the new ones from MAXIM electronics look nice.
As well, this is why I could never get the Universal T Board to work on my Racegun.. I took a look at the schematics and the LVR on it couldn't sustain anywhere near that much.. I would be curious to know if anyone got a univ-t-board to work in a Racegun. As well if anyone has gotten this to work, it would allow me to know if I could go to a smaller size transistor since the power draw isn't needed.

Linear Voltage Regulator
Part Number - LM2936MP-5.0
DataSheet -
Size - SOT223

NPN Transistors - These are what takes the low voltage signal from the microprocessor (arduino) and triggers a switch to turn on the higher current solenoids. I chose transistors with integrated diodes for simplicity, and that can handle 1A sustained.. This is overkill for the F1 5way and I may change it down the road for space savings. For now it will be the same so I don't have to organize so many different parts.

NPN Transistors
DataSheet -
Size - SOT89

Connectors - Argh.. If it were up to me I think I would just hard solder the connectors because I dont know how many people I have helped with microscopic bits of broken plastic.. That being said, not everyone can solder, so I guess connectors are handy.. Just be careful when removing those things! I decided to go with straight headers (current race board is right angled) due to my space needs, but if it doesn't work out right angled connectors might come back into play.

2 Pole Connectors (Noids, Batt)
4 Pole Connectors (Eyes)
6 Pole Connectors (Button Pad)

I placed a order from Digikey (Try mouser, they are GREAT as well) for the parts and I hope to get them, and the soldering station in soon.. Then the fun will start, since Ive never soldered SMT components in my life, or custom made my own PCB! Oh well, should be fun all the same!

Now that I'm using CAD software (NRO I'm sure can relate) its making it a lot easier to make changes if needed.. EAGLE CAM is awesome if you ever need to set something like this up, and there is even a free version so you can try it out.