@Arbiter, using a relayshield for all other operations(mostly savety) but its not suitable(not fast enough) for making a spark. tried that in the beginning.

just use a basic socket implementation and return some json strings

 

if the request is good i parse it and throw it in an handler class that executes the operation and its response will go back on the socket as json.

works great with AJAX requests

How on earth did I miss this project until now! I so want to make something similar and plan on using the Sparkfun Gap Ignitor. 

 

Great work Frankie. Awesome project. 

 

Steve

 

We had a DIS from a friend.. its one from a toyota aygo.

The signal from the netduino went to a relay(controlled by the netduino) then through one of the missle switches through the cable to the little box in the first picture where the transistor was.

I used D0 on the netduino and switched the relay from the netduino. The missle switch was just another precaution because you had to physicle clear the line.

 

I've put a 18K ohm resistor on the base and 5v on the collector. In the little box is a small push button to manual make a spark for testing. the signal wire from the control unit was also protected by a diode so there wasnt going to be 5v on the line when you pressed the push button.

 

ive stabalized the power from the car battery with these from bitwizard: power stabalizers

 

next year we get the linux drivers compiled on the PI for the touch screen and the WIFI Accespoint.. 

 

ps. if you need the code, send me a PM.. im happy to share it

 

psps im gonna get me an ignitor from sparkfun..looks awsome, just have to find the correct mosfet for it... have to shop for new gear anyway now my netduino plus is stuck in a lexaan box lol

Hi guys,

 

I just wanted to show you what we made with the netduino.

The netduino runs a small webserver accepting commands and produces JSON output. Im using an EventHandler factory and different mappers for the functions and hardware commonication.

 

Special thanks to Paul for helping with the transistor solution, NeoMika who's webserver project became the base for the Webservice, Wouter Huysentruit for the JSON parser and everybody on this forum for contributing.. The wiki was great help for getting the RGB leds working. thanks to Adam S from financecoding for sharing the code for the relayshield.

 

Near the end the code didnt got any nicer and had some resource locking issues, at a point the netduino would stall in debug mode while trigerring the DIS. I solved it by removing the webservers event handler and locking the trigger method.. not very nice but very functional when youre out of time.

 

anyway.. thanks a million for the support guys!

 

The controlunit for the canon, elevation adjustment, trigger and manual control

 

more detail:

 

 

Conrol unit:

 

wifi accespoint(emergency solution as we couldend get the wifi running on the PI

 

 

buttons/switches on the lid as wel as some gages and the touchscreen

 

 

 

 

And here the webapp(loaded from the raspberry PI) that controlled it all.

http://heuveltje.net/boom/

 

Heppy new year and on to the next project

Oh dear, what have I done?

Holland now have weapons of mass destruction.
What happened to growing tulips - I thought that was fun

On a serious note, don't use any of the transistor circuits above to trigger the DIS.

If you have not come across it yet on the forums, there is a design feature with most of the digital IO pins. When the Netduino resets or powers up, the IO pins are pulled high by internal resistors. These resistors will give enough current to turn on the transistors above.
If your Netduino were to be switched on, or if it was reset unexpectedly, you could start a war with Belgium or worse - burn your eyebrows off.

A simple fix but still not very safe is to use one of the IO pins that does not get pulled high (A4 or A5).

However, what I would recommend is that you use a low current opto-isolator and drive it from two Netduino pins. One to be taken high and one low. This will prevent war with Belgium due to a reset, and make it less likely a software glitch could accidentally fire the DIS. Ideally have two tasks one controlling each pin. I mention this idea in the following Wiki page

Have fun but do it safely - Paul

Safety first is our credo
a war with Belgium isnt really the problem, no challenge in that lol

I've read about the the problem that the pins get pulled high but i havent seen a spark yet while the netduino was powering up, ive used my netduino basic for small testing.
I will have a look at incorporating an opto-isolator. At this time i used one of the unused relays on my relay shield as an extra precaution.

ps. We've been doing this stuff for almost 10 years without an incident, we'll be fine

Car Jack: Led strip:

Hi Frankie,

I'm not sure why, but I seem to have missed several updates on this post so I've got a bit out of step with all the updates and suggestions!

That last diagram looks right. Before I saw your diagram, I drew the attached this evening to show you what I meant.

1/ The circuit from the example you started with. The transistor is fully ON, so it has a voltage drop of about 0.3V and most of the 5V supply is available to the load. The base of the transistor is about 0.7V above the emitter. In this circuit the base voltage does not really matter.

2/ Using this to drive the DIS. Note that the negative on the 12V battery is NOT the same as the Gnd of the Netduino. The transistor bridges these signals when it turns ON.

3/ I think this is what you had initially. In this circuit the base emitter voltage matters. The emitter must be about 0.7V less than the base, and the base can only be 3.3V at the very most. Hence the emitter can only be 2.6V. (3.3V - 0.7V = 2.6V) So the load only gets 2.6V not 5V! The rest of the volts are lost across the transistor which acts as a resistor because it is not fully ON.

4/ Using a second (pnp) transistor. Now one npn transistor turns on a pnp transistor. In this case the 0.7V base voltage drops are both next to the rails, hence both transistors can turn on fully and the load gets the full voltage.

5/ How it would be applied to the DIS. Now all the circuit uses the same ground.

I hope this sheds light on the issues - Paul

PS, should I ask why you are making big sparks?

Thanks Paul, im now using schema 2.

On what I'm going to do with the spark, well that's a long story but ill try to keep it short.

INTRO:
Im from the eastern part of Holland and we have a tradition at the end of the year, we shoot with old milk canisters or other contraption. We use calcium carbide gas to do that.
heres a small video of what it is:

and some build like this:



Last year we made a gun on a trailer with a recoil system, modified a car jack and added a windscreen motor to it to make it go up and down etc.. etc. To get the accetelyne gas from the carbid you have to poor water over it and it starts to gass, because its a very messy and inefficient job we've build a gasifier that hold clean gas
The gassifier has 3 savety valves and never goes over 3 bar of pressure, its rated for 10bar pressure.

We build everything ourselves with scrap metal, using a angle grinders and welding equipment!

Anyway this year im going to automate it with the netduino, ive already programmed a platform on the netduino to handle Ajax requests and response in Json, created a whole interface layer for the hardware and services to manage it all. I created a request mapping class to map commands like ~ipaddres\firecontrol\armIgnition or ~ipaddres\jackcontrol\0 where 0 is the enum down. etc etc.

To control it all I have build a mobile webapp with JQuery mobile and loads of javascript: http://heuveltje.net/boom/
Because the netduino isn't capable to host the mobile web-app(found out the hard way) I have bought a Raspberry Pi to host the web-app. Raspberry was pretty easy, put Debian on the sd card, get all the packages in with aptitude, set permissions and presto. All you have to do to make it work is modify the header in the apache config to allow cross domain call. Oh and set the Jquery setting

So what's left to do now is make a power stabilizer to get the 12v car battery to 5v, for the transistor, ada fruits RGB led strip and to power the raspberry Pi. Then I have to make something to stabilize the car battery to 12v. The car jack and DIS igniter get their own private car battery cause they will be on the trailer and pull loads of amps. Im almost done coding, have to add some buttons and update the screen for the settings.
The devices are connected through a small Wifi AP

When I have it all done, its going to be in a lexaan box, with buttons etc. looking pretty in the field with all the LED's.

The team of idiots consist of a netwerk expert from Thales, Lotus dealer/race driver/shop manager, technical drawer/teamleader and me the software engineer/welder.

As you can read, the weakest part of the team is the fine electronics

ps. we've been add this for many years and for example the gassifier is at version 2.5 already. The cannon and trailer are getting an overhaul too but all less drastic than last year because we don't have that much spare time left.

If it wasnt for this forum and all the wonderful tutorials wouldend have gotten so far in such a small amount of time, really great this community. When its all done ill post the code for others that need inspiration

latest schematic

I have it now like in the schematic attached. And what you see in that little movie. Ill draw up what you said earlier and see how that goes. Thanks so far for all the help

Hi Paul,
I've made you're schematic in smartdraw and I makes a lot more sense and it definitely works so im sticking with youre suggestion

thanks a lot for helping me out here, very much appreciated

If you've connected the emitter to the control wire, you will not be getting the full 5V, you will actually be getting the Netduino's 3.3V minus the base-emitter drop of about 0.7V. So I think the voltage on the control wire will only be about 2.4V.

I have it now like in the schematic attached. And what you see in that little movie. Ill draw up what you said earlier and see how that goes. Thanks so far for all the help

Thanks for the pointers guys, itssssss SOLVED, connected the emitter directly to the control wire and it goes awesome now. Used my Netduino basic for a small program, changed the resistor to the base, connected to D0 and connected the ground and here is the result: ps. Are there things to worry about, like frying the transistor or netduino anytime soon

Hi Paul,

ive made a quick schematic with SmartDraw, not the prettiest but i hope it helps.

In de schematic i have left the netduino out and just uses a 5v line to open and close the transistor

now with attachment

Hi Frankie,

Can you show us how you wired everything up?

Paul

Hi Paul,

ive made a quick schematic with SmartDraw, not the prettiest but i hope it helps.

In de schematic i have left the netduino out and just uses a 5v line to open and close the transistor

Hello peeps, I have a problem getting a DIS to fire with a transistor and my lack of electrical knowledge has me bogged down so i was hoping for some help. The DIS im using is powered by 12v battery and fires with a controlwire that takes 5v and about 14mA. In getting this to work im using the BC547B transistor. The transistor works fine from the neduino, i check with a led and it powers on and off just fine. ive used this as a reference: http://www.danielsol...heets/BC547.pdf At first i used the 5v of the netduino on the transistor but after that didnt worked i added an additional power supply at 5v but that didnt work either. When i put the 5v directly on the trigger of the DIS it works fine so everything works except for the firering with the transistor. Plan B was to use the netduino relay shield and that works fine. What am i doing wrong? I also have a IRF520 MOSFET lying around, should i use that one? ps. ive added a youtube video with the sparl: