PWM Out Of The ULN 2803 and Vixen

[Buzzkill]

Thanks for all the previous thoughts on my project. 

In the previous post I aksed about maximum milliamp ratings on the ULN 2803.  I am driving 400ma of LEDs through 2 outputs at a time for a total of 800ma, but only for a few seconds each time.  That is all working great.  Since I am direct driving the LED's and programing with Vixen, can I assign dimmer/intensity values to the channels in vixen for the channels with the LEDs?  Or is this strictly an on/off control?

Thanks!

Ray

[JonnyMac]

The EZ-8 is a "bit banger" and can only store on or off states.

[JackMan]

can I assign dimmer/intensity values to the channels

Are you looking to fade the LED's or just turn them on at a lower intensity? 

[JonnyMac]

Again, the EZ-8 has two output intensities: 0% and 100%.  If you use analog values in Vixen they will be converted to digital (you can set the threshold) for the EZ-8.

[Buzzkill]

Thanks for the replies.  Since this is a cannon, I was going to fade the LEDs at the end.  But as it turns out, the LEDs are not as bright as I had hoped behind the co2 so on/off is fine.  Next year I will up the ante and throw some 1-3 watt LEDs into the mix.  But a scout is thrifty.  So I used what I had, which was a bunch of 8mm straw hat LEDs.

I will post to the project forum section soon.

RD

[JackMan]

I know the EZ-8 outputs are either on or off but I was going to suggest using any extra available outputs coupled with higher value resistors (paralleled to the existing LED outputs) as an option to dim the LED's. It would not be a fade, just on with less intensity.

[JonnyMac]

Sorry, I misunderstood.

[JackMan]

Hey no worries, it's impossible to know what's on everyone's mind!  8)

[bsnut]

I like your idea Jack, I didn't even think about doing it that way myself.