Pump operation before match

[Jeff Waegelin]

Does anyone know how to make the compressor turn on before the start of the match? We would like to have our compressor be charging before the match starts, but I can't figure out how to do it. I know we did it last year, but I can't for the life of me remember how I did it last year. Can anyone help me with this?

[Matt Reiland]

As far as I knw, the pump should have been driven from either a Spike or Speed Control which would not have ad a PWM signal before the start of the match!? So I don't think it should have been running before the match but you can precharge the pneumatics system in the pits before you place your robot on the field. We will be doing this as we don't have the compressor on-board the robot

[pras870]

I'm assuming you want to charge your air tanks before he match starts so you are not wasting time trying to charge them during the match. To do this, simply hook up the compressor to a spike relay, and program it to be on all the time. The pressure switch will turn the compressor off at approx. 115 psi.

[Nate Smith]

Originally posted by Jeff Waegelin
Does anyone know how to make the compressor turn on before the start of the match? We would like to have our compressor be charging before the match starts, but I can't figure out how to do it.

Due to the requirement of having to run the compressor through the Robot Controller, there is no legal way to have the compressor charging while the control system is disabled. However, it is possible, as has been mentioned already, to pre-charge the tanks before you place your robot on the field, using the tether connection in the pit area...

[Jeff Waegelin]

Yeah, that was our plan up to this point. I guess we'll just have to live with pre-charging.

[rust710]

Last year with the Red relays you could have done it if I understand correctly that the Red relays where normaly closed switches, but what does it matter, no Red relays this year.

[Matt Reiland]

From the Spike Manual for RED

Table 1: Spike Red P-BASIC software control, Spike output, Motor function
INPUTS OUTPUTS
Fwd Rev M+ M- Indicator Motor Function
0 0 +12v +12v Orange OFF / Brake Condition (default)
1 0 +12v GND Green Motor rotates in one direction
0 1 GND +12v Red Motor rotates in opposite direction
1 1 GND GND Off OFF / Brake Condition

It appears that with no PWM signal 12V would be available at both terminals, so unless you put the pump to only one terminal and the other side to the ground, it shouldn't have worked on the RED spike either. (No voltage difference between Black & red on the pump)

I think the intention of the Control System is not to have any outputs functional when the Control System is Disabled

[Josh Hambright]

Either precharge your tanks using the tether cable or you could do what some teams have begun to do and just build a tank charger using a pump , battery, fuse and some kind of switch. Just open up your main relief valve and pump preasure into the system then when you get to 120 shut the valve and unplug the external pump. That way you start with fully charged tanks so your pump doesn't have to waste time charging them.

I hope i explained that clearly enough. We are working on finishing out external pump assebly tonight and i'll post pictures when its done.

[Yan Wang]

A good pneumatic system without the slightest air leak would do fine with precharging, as all the air would stay there :) Unfortuneately, for most of us, it leaks a tiny bit, so I suggest charging it as late as close as possible to the match time.

[Jeff Waegelin]

Originally posted by Matt Reiland
From the Spike Manual for RED

Table 1: Spike Red P-BASIC software control, Spike output, Motor function
INPUTS OUTPUTS
Fwd Rev M+ M- Indicator Motor Function
0 0 +12v +12v Orange OFF / Brake Condition (default)
1 0 +12v GND Green Motor rotates in one direction
0 1 GND +12v Red Motor rotates in opposite direction
1 1 GND GND Off OFF / Brake Condition




Is there something like this available for the Spike Blue?

[Matt Reiland]

Originally posted by Jeff Waegelin
Is there something like this available for the Spike Blue?

Why yes there is: (From Innovation FIRST Website)
Table 1: Spike Blue P-BASIC software control, Spike output, Motor function
INPUTS OUTPUTS
Fwd Rev M+ M- Indicator Motor Function
0 0 GND GND Orange OFF / Brake Condition (default)
1 0 +12v GND Green Motor rotates in one direction
0 1 GND +12v Red Motor rotates in opposite direction
1 1 +12v +12v Off OFF / Brake Condition

[Rickertsen2]

whoa i never knew the spikes brake.

[Matt Reiland]

Originally posted by Rickertsen2
whoa i never knew the spikes brake.

Brake = Connect both leads together

[rust710]

I wish I knew that about the spikes last year. Could have been very useful.

[Jeff Waegelin]

So, in theory, could you accomplish what I'm thinking of by using a red spike and hooking the black wire of the compressor directly to ground? I'm already thinking it's not a good idea, but would that theoretically work?

[Matt Reiland]

Originally posted by Jeff Waegelin
So, in theory, could you accomplish what I'm thinking of by using a red spike and hooking the black wire of the compressor directly to ground? I'm already thinking it's not a good idea, but would that theoretically work?

Theoretically I can't see why it would not work, the pump would be on any time that the relay fwd or rev were set to 0 (Depending on which you wired it to) Strangely I can't find it in the rules where it states which devices can be tied to the GND Blocks.

Here is what it says:
Except as noted herein, each Ground (GND) wire from a speed controller, relay, or Robot
Controller must go directly from that item to one of the 12 Common (-) terminal tabs on the
circuit breaker/ fuse blocks.
Exception: The Ground (GND) wires from low current items such as solenoid control and
rotating light relays, custom circuit, optical sensors, LEDs, and fans may be connected as a
group to one common wire leading back to a Common (-) terminal tab.

But it doesn't specifically seem to say the output side of the spike or speed control to the motor, however the exception is for low current items only. Either way the RED is no longer available so it doesn't matter much.

[Lloyd Burns]

And last year, with red spikes still allowed, all you needed to do was have the compressor connecter to a Red (+) and a Blue (-) Spike, to have it turn on. As long as no one caught that you were using the different types of Spike, and as long as no one insisted that the compressor be connected with both leads to the same Spike.

Alas that is (and Red Spikes are) unavailable to you this year.

[IronSlayTallica]

Try having a spare battery, preferrably an old one used just for charging the tanks before the match. Just keep it outside the robot and plug it in the way any normal battery would be used. Have the compressor set to be run all the time and it'll switch off around 120 psi. Once that's done, plug the regular battery back in and you're ready.

[KenWittlief]

If there is anything running on your bot before the match begins (before FIRST enables the controllers) your bot will be disqualified.

You cant jury rig the wiring to bypass the intent of the judges match Start/Stop switch.

If you did this, you could also have motors and other actuators running before or after the 2 minute period.

Keeping your tanks full before the match is part of the challenge. make sure all your fitting have teflon tape properly used - all fitting are good and snug (the BIG grey solonide requires you to use a Hex wrench inside the fitting to tighten it)

and make sure all your hoses are pushed in, then pull them out firmly to seat them.

If your pnumatics leak then your bot is not properly assembled - you cant play well will a poorly assembled bot

if you are going to break the rules, you might as well break all of them, right?

[Josh Hambright]

Here is a picture of our external pump that i said i would post:

http://www.chiefdelphi.com/forums/pictures.php?s=&action=single&picid=5100&direction=DESC&sort=date&perrow=4&trows=6&quiet=verbose