Forum: Programming
14-06-2016, 02:24
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Replies: 12
Views: 2,005
Re: A few questions about the control system...
In LabVIEW on a cRIO (running VxWorks), you can use timed loops to get excellent timing accuracy. Self-measured jitter (reported by the OS) is usually tens of microseconds. I can't speak for other...
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Forum: Programming
13-06-2016, 20:21
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Replies: 12
Views: 2,005
Re: A few questions about the control system...
You should have no problem getting 100hz+ execution rate on a RoboRIO.
In the cRIO2 days, in LV, I was able to achieve a 10ms loop time with probes open. Without the overhead of probes, I believe I...
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Forum: Career
10-03-2016, 21:20
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Replies: 198
Views: 35,029
Re: What's your day job?
I have a new job since I last posted.
I'm currently working at Williams International, working on embedded software and electronics design for commercial turbofan engines. Some of the projects I...
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Forum: Technical Discussion
21-02-2016, 02:42
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Replies: 6
Views: 782
Re: Xbox 360 sticking issues
The short answer is, that's just what the xbox joysticks do.
The Logitech F310 is much better, we no longer use Xbox joysticks because they do not return to center well and it really bothered...
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Forum: General Forum
20-02-2016, 18:26
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Replies: 5
Views: 655
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Forum: Pneumatics
20-02-2016, 00:20
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Replies: 9
Views: 1,106
Re: Wiring Multiple PCMs
At high speed (1mbps), the recommended max bus length for CAN is 40 m. At this length, the actual electrical design is important and two 120 ohm resistors (one at each end) are a must.
CAN also...
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Forum: General Forum
19-02-2016, 22:49
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Replies: 69
Views: 7,309
Re: Poll: How many CIMs are you using?
You wouldn't need reduction on a CIM or MiniCIM? Relatively few mechanisms work well without any gearing at all.
A VP stage and ring gear (not including ends) is 0.132 lbs, well under the weight...
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Forum: Electrical
19-02-2016, 22:34
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Replies: 1
Views: 598
Re: How to wire CIM Coder(am-3314)
The datasheet says it can be supplied with 4-24v nominal and that the pull up voltage should be the same as the supply voltage.
You should probably power it off off of the 5v sensor supply available...
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Forum: General Forum
19-02-2016, 22:13
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Replies: 69
Views: 7,309
Re: Poll: How many CIMs are you using?
It's all about power and weight.
BAG motors are good for ~150 watts of power and is listed at 0.71 lbs
MiniCIMs are good for ~215 and 2.16 lbs
So changing from a BAG motor to a MiniCIM gets you...
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Forum: Pneumatics
19-02-2016, 21:53
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Replies: 9
Views: 1,106
Re: Wiring Multiple PCMs
The order does not matter for CAN. You can also put the PCMs after the PDP on a bus as short as an FRC robot.
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Forum: Technical Discussion
18-02-2016, 20:32
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Replies: 30
Views: 2,487
Re: Shutting Down a Robot-Mounted Pi
As long as you never write the SD card, then the SD card's wear leveling feature shouldn't try to move blocks around.
This requires:
-Disabling swap entirely (it's generally a good idea to disable...
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Forum: Programming
17-02-2016, 21:36
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Replies: 4
Views: 1,025
Re: Do we need to wait between CAN Bus commands?
In general, CAN (in general, not specific to FRC) is implemented as an isochronous network.
This means that real-time data on the network is continuously retransmitted at some interval, and only the...
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Forum: Programming
07-02-2016, 23:09
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Replies: 5
Views: 851
Re: Reset navX roll
Since it's reported to you as a float, it will never exactly equal zero. Floating point numbers aren't exact, they are only approximations, so you can never use an == comparison on floats or doubles...
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Forum: Technical Discussion
07-02-2016, 01:31
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Replies: 16
Views: 1,981
Re: Good #25 chain breaker?
You should look for a 'dark soul' chain tool.
We have this one (http://www.team221.com/viewproduct.php?id=70)but they don't stock it any more.
Here is one that I found with...
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Forum: Electrical
06-02-2016, 22:41
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Replies: 15
Views: 2,076
Re: PNP versus NPN sensors
You can use an NPN BJT with a single series resistor of high enough resistance to limit the base current. I don't think the voltage divider is necessary.
You can also use a FET with a pull-down...
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Forum: Technical Discussion
02-02-2016, 22:14
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Replies: 2
Views: 575
Re: ntpdate on port 123
Do you actually need the time on them?
Most embedded systems will never know their current time, and don't really care. I can't imagine an image processor needing it's current time at all.
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Forum: Programming
02-02-2016, 21:36
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Replies: 18
Views: 3,517
Re: Shooter Aiming with Tables
Not sure why you would say this, but a well implemented table is way easier to modify/generate than a function.
For a function, if you want to 'recalibrate' based on test shots, you have do do a...
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Forum: Programming
28-01-2016, 00:06
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Replies: 7
Views: 1,111
Re: FRC Sonar Reading Delays
Post some code?
What type of sonar sensor is it, and how it it configured in software?
Some output an analog voltage. These should be pretty clear and easy to use with an AnalogInput.
Some have...
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Forum: Extra Discussion
08-01-2016, 23:37
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Replies: 2
Views: 938
Re: paper: JVN Calc + Apalrd's Time to Distance
In 2012 we (33) did math using the old JVN sheet (before battery voltage calculation was added) assuming 11v instead of 12 or 13.2v (this was how we compensated for the voltage drop in acceleration)....
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Forum: Extra Discussion
08-01-2016, 07:37
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Replies: 13
Views: 2,434
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Forum: Extra Discussion
07-01-2016, 21:46
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Replies: 13
Views: 2,434
Re: paper: Apalrd's Choo-Choo Analysis Spreadsheet
33 2014 used a NBD ('Nothing But Dewalts') transmission with the CIM interface. We had ordered a huge number of DeWalt replacement parts when NBDs were popular and are slowly using them. I wouldn't...
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Forum: Extra Discussion
07-01-2016, 13:53
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Replies: 13
Views: 2,434
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Forum: Extra Discussion
07-01-2016, 13:26
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Replies: 13
Views: 2,434
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Forum: Extra Discussion
06-01-2016, 21:43
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Replies: 10
Views: 1,688
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Forum: Extra Discussion
06-01-2016, 21:21
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Replies: 10
Views: 1,688
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Let's see. There's the Dean of Students, the Dean of Admissions, The Dean of Engineering, and the Dean of Kamen? Sometimes known as the Denim Dean. - Bill_B [more] 
