OI LEDs on the 5v Aux

[ShadowFireGT]

What are the consequences(if any) of using the 5v aux pin to power a parallel circuit of LEDs. Each LED will have it's own resistor. The switches have two circuits and the LED and digital input will share a common ground, but otherwise will have separate circuits. It would be a lot easier to do it this way then to steal LED drivers from the other ports and wire each one separately. Also, doing it that way would eliminate the usability of the programmable LEDs due to their being in a constant on state.

[Ari Allyn-Feuer]

I don't foresee any negative consequences as long as it's legal and doesn't draw too much power. Remember that the 5V circuit on the RC tops out at one amp, so you only have five watts available, and some of that would be great to use on sensors and switches!

You might want to do a step-down from a 12V output (or get 12V LEDS) and put the circuit on a spike.

Ari.

[ShadowFireGT]

This is for the operator interface. From the OI reference guide:

[1] The DISABLE dipswitch on the Operator Interface
[2] LED drivers provide 5V at 10mA
[3] +5V Aux is to be used for potentiometers in Joysticks and custom I/O boxes.
[4] Do not use +5V Aux for lamps or LEDs.
[5] The current limit of the +5V Aux from all 4 ports is about 100mA. The Aux Fault Led will start illumination when the current draw from the +5V Aux Outputs total about 120 mA and the +5V Aux voltage will have dropped to about 4.5 volts. Worse case, short condition: after about 30 seconds, the voltage will be at about 300 mV with a current of about 250 mA.

The reason I ask this is due to number 4. But this isn't stated in the rules themselves. Will doing this void a warranty or something else that I don't want to do?

[Dave K.]

Originally Posted by ShadowFireGT

This is for the operator interface. From the OI reference guide:

[1] The DISABLE dipswitch on the Operator Interface
[2] LED drivers provide 5V at 10mA
[3] +5V Aux is to be used for potentiometers in Joysticks and custom I/O boxes.
[4] Do not use +5V Aux for lamps or LEDs.
[5] The current limit of the +5V Aux from all 4 ports is about 100mA. The Aux Fault Led will start illumination when the current draw from the +5V Aux Outputs total about 120 mA and the +5V Aux voltage will have dropped to about 4.5 volts. Worse case, short condition: after about 30 seconds, the voltage will be at about 300 mV with a current of about 250 mA.

The reason I ask this is due to number 4. But this isn't stated in the rules themselves. Will doing this void a warranty or something else that I don't want to do?

For more detail than perhaps you are looking for, read through one of my previous posts here.

To answer your origional question directly, the consequence is that you'll pull down the voltage on the +5v aux pin, and thus limit the maximum value that any of your analog joystick values could report. For each ~4.4mA of current drawn from this pin, the maximum A/D count will drop by 1 count. If your LED's were powered all the time, then your software could account for this, but if the LED's were modulated on and off, then the analog values for all of your joystick postions would be modulated along with the LEDs.


For LED power, please see the latest IFI documentation. I pointed out some errors to IFI and they've updated them to properly indicate that the outputs are not specifically 5v outputs. Unless you are using the LED outputs for something else, these outputs would be the best ones to utilize for general illumination requirements.

[ShadowFireGT]

Awesome, thanks a lot. I guess I'll use the LED drivers to avoid messing up our joysticks. Programmers wouldn't be very happy with me.

[Dave K.]

Originally Posted by ShadowFireGT

Awesome, thanks a lot. I guess I'll use the LED drivers to avoid messing up our joysticks. Programmers wouldn't be very happy with me.

Also note that the LED driver ports will work well with Red, Yellow and Green LED's and do not require any additional series resistance, just wire the LED's as explained in the updated IFI documentation.

Blue and White LED's may or may not work because of the higher voltage required to light them, the resulting current provided by the operator interface may not be enough to light them brightly. If you do go down that path, look for higher efficiency LED's and consider the information in IFI's updated documentation along with some of the information in my past posts that may provide some additional insight.

[whytheheckme]

Meh...

I'm using my 5V+ to power LEDs in 4 of my switches. I notice no 'lag' or unusability in any of my devices. I'm also currently using a couple of relays to control higher voltage devices (until I'm told otherwise that I can't).

I made a schematic in Capture, if anyone is interested, I can get a copy tomorrow and post it.

So my vote is that you can power a few LEDs, but not enough for decoration.

Jacob

[Mike Betts]

Originally Posted by whytheheckme

Meh...

I'm using my 5V+ to power LEDs in 4 of my switches. I notice no 'lag' or unusability in any of my devices. I'm also currently using a couple of relays to control higher voltage devices (until I'm told otherwise that I can't).

I made a schematic in Capture, if anyone is interested, I can get a copy tomorrow and post it.

So my vote is that you can power a few LEDs, but not enough for decoration.

Jacob

Jacob,

You have posted on a number of threads about this.

If the relays are touching the OI port and also are touching another voltage source, it is illegal and the inspectors will make you disconnect them before you are allowed to pass inspection.

Regards,

Mike