Control of Decorations (Led displays)

[tagayoff]

How does one go about controlling the on/off function of some LED displays.
<R44> Lets you power them but <R60> says you can only control pneumatic solenoids and now line tracking sensors (Update). So do you build a custom circuit the can take a DI/O output to control them or are they just on all the time? Rookie team member is .

[foozie]

You can use the DIOs on the Digital Sidecar.

[Alan Anderson]

We'll be using a Spike relay module to power our robot's lights.

[KHall]

May I suggest you look at some of the 'blinky LED' projects listed at this site:

http://www.kpsec.freeuk.com/proj.htm

If you want to learn more about how to create the projects, there is a link at the bottom of that page that says "Study Electronics". Click on that and proceed page by page though the instructions. Should only take a little while. If you come to a page that does not interest you, just skip it for now. You can always go back and review it later. When you're done, you'll fully understand the information listed for each project. With a little work you can modify these projects for your robot.

If you're looking for the parts, let me know. I can recommend a good place to get these things in the USA that won't cost too much.

Regards,
KHall

[tagayoff]

I guess I haven't made myself clear yet. I would like to use some (3) joystick buttons to turn on/off three sets of led displays that use 12volts. I know I could use 3 spike relay modules but that seems overkill. (But it may be the only way it's permitted.) The DIO's only drive miminal current at 5 volts I think. I would have to have a custom driver from that to switch the 12 volts . That would be more reasonable but is it permissible?

[WizenedEE]

You can build whatever custom circuit you want to control decorations and non-motors, is what our team decided. Rule <R04> (I think) says you cannot control "output devices" with custom circuits or COTS electronics. We decided that LEDs are not output devices.

If you want to use spikes, you can easily control each of the two leads directly, so that's LEDs per spike. See this thread: http://www.chiefdelphi.com/forums/sh...ad.php?t=89207

[Al Skierkiewicz]

Adam,
It's R03. The 9403 data I/O module is directly connected to the digital side car I/O and the sum of all outputs cannot exceed 64 ma. Using the digital outputs for LEDs is not a good idea. I believe that a high current LED driver would be legal as a custom circuit provided it does not violate any other rule, specifically electrical rules. Spikes are still the best alternative as far as ease of use, interface and wiring.

[dsmith14469]

Here is a simple circuit using a MOSFET Switch. http://www.newark.com/vishay-semicon...68?Ntt=66M1368

This MOSFET is overkill for simple LEDs, 2 Amp rating.

Just connect the DIO from the digital side car, add the correct resistors to not fry any parts and you should be good to go.

Hope this help.

[maddoctor90]

<R56> Relay module outputs, speed controller outputs, or PWM outputs must not be connected to the analog/solenoid breakout boards or the Digital Sidecar. 12Vdc power must not be connected to any terminal on the analog/solenoid breakout boards or the Digital Sidecar except the designated 12Vdc input terminals. (Doing so may damage or destroy components of the control system.)

So, you can't use the 12v off of the sidecar. Although, I am not sure if you can use the 5v to switch a 12v source legally. At a quick glance at the rules, I think it would be ok, although I would want to make sure first for yourself. My team will be using three relay modules for about the same thing because it is easy and we know it is legal. I would suggest you do the same, unless you have some reason not to, or have extra time and feel like experimenting around.

[AndrewN]

Each "spike" can switch two circuits: there are two relays inside that can switch between +12V and 0V. The "fwd", "rev" control signals each control one relay. You could control 4 separate light ropes with 2 "spikes". The "ground" from each rope would be connected back to a black terminal on the power board.

[tagayoff]

Now you tell me after I bought 3 spikes. I guess I should

[Al Skierkiewicz]

First Engineering has now made it easy for you. The IFI docs are linked on the KOP page so you can read the install and use docs for robot components all in one place.

[DavidGitz]

Originally Posted by AndrewN

Each "spike" can switch two circuits: there are two relays inside that can switch between +12V and 0V. The "fwd", "rev" control signals each control one relay. You could control 4 separate light ropes with 2 "spikes". The "ground" from each rope would be connected back to a black terminal on the power board.

<R42> Each power-regulating device (speed controller or relay module) shall control one and only one electrical load (motor, actuator or compressor).
Exception: Multiple low-load, pneumatic solenoid valves may be connected to a single relay module. This would allow one relay module to drive multiple pneumatic actions. No other electrical load can be connected to a relay module used in this manner.

From my understanding, a spike can control 2 circuits only if they are low-load, pneumatic solenoid valves. So you cannot control 2 different LED's (although I'm sure the current requirement is comparable).

If someone here disagrees, please let me know. Right now we have 3 relays for this purpose and I would not mind going down to 2!

[Alan Anderson]

Originally Posted by DavidGitz

<R42>...

From my understanding, a spike can control 2 circuits only if they are low-load, pneumatic solenoid valves. So you cannot control 2 different LED's (although I'm sure the current requirement is comparable).

If someone here disagrees, please let me know. Right now we have 3 relays for this purpose and I would not mind going down to 2!

I read <R42> as applying to motors, actuators, and compressors. I do not believe it applies to custom circuits.

(As always, my opinion counts for exactly nothing when your robot is being inspected.)

[DavidGitz]

So they list the exception as a valve could be considered an actuator? That is a good point.

Off to do some GDC Q&A Research.