Showing PSI in user mode?

[Billfred]

Alright, I've seen certain people say that they've been able to get air pressure to appear as the user byte on the OI.

The problem is, I'm not sure how to read such data from the RC, and searching CD doesn't seem to turn up any information.

Can anyone shed some light on this?

Thanks!

[Greg Marra]

Originally Posted by Billfred

Alright, I've seen certain people say that they've been able to get air pressure to appear as the user byte on the OI.

The problem is, I'm not sure how to read such data from the RC, and searching CD doesn't seem to turn up any information.

Can anyone shed some light on this?

Thanks!

User_Byte1 = yourvariablehere;

Then you can push the 'select' button on the operator interface to toggle between the different userbytes (you can define up to six). I believe that userbytes 1 and 2 are the only ones that show up on the OI, but I haven't been able to check this. Actually, I haven't even been able to check that the code above works. I'm only about 80% sure it does. All of the userbytes can be read through the Dashboard port by a Dashboard program.

Hope that helps.

[Billfred]

Well, that's half of the battle.

Now, at the risk of posting this in the wrong forum, how do I read the information from the pneumatic system to the RC?

[steven114]

There was an analog pressure sensor provided last year, not sure if it's in the kit this year, but I would guess that it would be legal anyways - probably off the shelf. It's just like any other analog sensor.

[Joe Ross]

Following the parts use flowchart, the analog sensor provided in the past may not be used this year. This is because it is a pneumatic component, which takes precedence over being a COTS electronic item.

Edit: see my post below

[steven114]

I'm sorry. I spoke without justification

That really is too bad, though - the analog sensor was quite a cool addition to the kit.

[Tom Bottiglieri]

Originally Posted by steven114

I'm sorry. I spoke without justification

That really is too bad, though - the analog sensor was quite a cool addition to the kit.

Few teams used the pressure transducer, and opted for the digital pressure switch. I believe FIRST opted for the accelerometer from TI over the pressure sensor because it wasnt a widely used item, and this years game moves alot of weight very high. This causes tipped bots, and the accelerometer may be able to help that.

[steven114]

You say that as if they were mutually exclusive items - both would be really cool. Personally, I would prefer the pressure sensor - I've had just about an infinite amount of trouble with integrating accelerometers in the past

They're too finicky for my taste - I prefer the sensors that just work.

[Joe Ross]

Originally Posted by Joe Ross

Following the parts use flowchart, the analog sensor provided in the past may not be used this year. This is because it is a pneumatic component, which takes precedence over being a COTS electronic item.

Actually, a pressure transducer is allowed in <R91>. It seems there is a box missing from the part use flowchart. You can use any pressure transducer as long as it is rated for the pressures you apply and you account for the costs.

[ntroup]

Originally Posted by Joe Ross

Actually, a pressure transducer is allowed in <R91>. It seems there is a box missing from the part use flowchart. You can use any pressure transducer as long as it is rated for the pressures you apply and you account for the costs.

I am not so sure about that. According to Q&A ID:1350:

Q: R88 indicates that the Nason pressure sw. is required if we use the pump, but it's not mentioned as a 'minimum' in R86. May we use the analog sensor instead? May we run the pump all the time and not install either sensor?
A: Part 1: You must use the pressure switch. You cannot use the analog sensor. Part 2: You may run the pump all the time; you can ignore the sensor BUT you MUST use the sensor. It is unwise to run your pump all the time as it uses power from your battery.

That seems to say very clearly that the analog sensor (pressure transducer) can not be used..... for whatever reason, I am not sure. Unless I am interpreting this wrong?

-Nate

[Joe Ross]

Originally Posted by ntroup

I am not so sure about that. According to Q&A ID:1350:

Q: R88 indicates that the Nason pressure sw. is required if we use the pump, but it's not mentioned as a 'minimum' in R86. May we use the analog sensor instead? May we run the pump all the time and not install either sensor?
A: Part 1: You must use the pressure switch. You cannot use the analog sensor. Part 2: You may run the pump all the time; you can ignore the sensor BUT you MUST use the sensor. It is unwise to run your pump all the time as it uses power from your battery.

That seems to say very clearly that the analog sensor (pressure transducer) can not be used..... for whatever reason, I am not sure. Unless I am interpreting this wrong?

-Nate

There are two possible interpretations. The first one is that the analog sensor may not be used under any circumstances. The second is the analog sensor must not be used in place of the pressure switch, but it may be used to supplement the pressure switch.

[ntroup]

Originally Posted by Joe Ross

There are two possible interpretations. The first one is that the analog sensor may not be used under any circumstances. The second is the analog sensor must not be used in place of the pressure switch, but it may be used to supplement the pressure switch.

I agree... I have read it both ways, but am not sure their intent on the ruling. If you read it point-blank, it looks like it is -not- allowed. But, I can't seem to figure out their reasoning behing banning it outright (as long as a pressure switch is also used), so I tend to think they are just meaning it can not be used are a direct replacement.

I continue to scratch my head at this, and some other of their answers...

[Mike Soukup]

If it's legal, here's how we did it last year before we were forced to use the digital sensor instead of the analog:

#define PUMP_120_PSI_VAL  223
User_Mode_byte = ((Get_Analog_Value(rc_ana_in01) >> 2) * (int)120) / (int)PUMP_120_PSI_VAL;