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 | | System Interrupts & frequency counting
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| I'm in the middle of planning/writing a small program that will read a digital input to determine it's frequency & pulse width. I thought it'd be nice to have this part of the program (in assembly) running off the system interrupt so that these (...) (27 years ago, 9-Jun-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.846)
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frequency
(score: 1.844)
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| | Re: A few questions
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| DVM or Oscilloscope: Most DVM will indicate the RMS or True RMS value of a sinewave with in the frequency range of the meter. Some functions to consider: Function DVM Oscilloscope Frequency Some via time for a period (or half period) RMS Sinewave (...) (27 years ago, 30-May-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.844)
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| | Re: System Interrupts & frequency counting
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| (...) I'm unfamiliar with the workings of IC, but if your interrupt service routine is sufficiently short, and you don't reset the interrupt mask to enable recursive interrupts, you shouldn't notice the difference. You asked if there was a more (...) (27 years ago, 9-Jun-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.844)
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| | Re: System Interrupts & frequency counting
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| (...) Paul, What you want to do is easy. All you need to do is get a small assembler routine which uses the Input Capture feature. Set the IC via registers to trigger when a rising pulse begins, it will stash the time and strigger an interrupt. Then (...) (27 years ago, 9-Jun-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.844)
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| | RE: weird headers
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| (...) Thanks, I stuck a pot in it's place and fiddled with it until I got 4.49k and it worked great. I came up with the 4.49k by taking 1/x*.0068 = 32.75. Where .0068 is the cap, and 32.75 was my desired frequency. So x was determined to be 4.49 (...) (27 years ago, 23-May-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.843)
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| | IR
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| Hello all, I've been playing with IR proximity sensors, and wonder if anyone can provide some suggestions. I hooked up an IR LED (Radio Shack 'high output IR LED') to the Handyboard's IR output with a 330ohm resistor in series (the smallest value (...) (27 years ago, 22-May-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.843)
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| | Re: A few questions
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| (...) I'm not personally familiar with that particular model, but I use a FLUKE with similar features. The frequency measuring is a nice addition. The inclusion of a bar graph in the LCD can be handy in looking at fluctuations. If I could have only (...) (27 years ago, 29-May-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.843)
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| | A few questions
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| Hi all, I'm about to build a few handyboards, and I have a few questions. 1. I don't have convenient access to an o'scope so I'm hoping to get by without one. I am in the market for a new DMM (my birthday's coming up :->), and I've located one that (...) (27 years ago, 29-May-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.842)
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| | flame sensing
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| Regarding sensing flame/arc...Eltec Instruments make pyroelectric detectors to detect flames and arcs emanating from arc welding etc.. Basically the detector has an filter which does not pass any light ] beyond the wavelength of 4 micrometers (...) (27 years ago, 3-Jun-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.842)
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| | Re: Communication with PC (2)
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| REF: TCP/IP & the HandyBoard Hello Mr. Chuck, Thanks for the feedback and sorry for the delay of my own feedback. I inquired about the TCP/IP alternative because we have acquired two Nomadic Technologies Mercury RF TCP/IP modems. They are (...) (27 years ago, 30-Jun-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.836)
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| | Re: LM34 temp sensor to handy board?
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| It sounds like you just want a standard non-inverting amplifier. wire an op amp like this: |\ sensor------|+\ | >-+-analog input of 6811 +--|-/ | | |/ | +----R1-+ | R 2 | GND where R1 and R2 are chosen such that (R1+R2)/R2 is the gain you want, in (...) (27 years ago, 21-Jul-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.832)
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frequency
(score: 1.816)
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| | Re: Microphone and Heat Sensors
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| (...) Interesting sounding project Melissa. The trick is to distinguish the doorbell from other ambient sounds heard picked up by the microphone. One approach might be to use the LM567 PLL Frequency Detector. Its a relatively simple little 8 pin IC (...) (27 years ago, 12-Nov-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.812)
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| | Re: Drive types
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| (...) NXC is something like NQC and it is available for Windows, Mac OS X, and Linux platforms. While NXC is not yet complete, it is very functional with a large API for the NXT. Not eXactly C (NXC) is currently available in the form of NBC beta 20. (...) (18 years ago, 8-Jan-07, to lugnet.robotics)
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post, frequency
(score: 1.811)
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| | RE: IR Demodulator Range Finder Hack
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| (...) Sure thing. The basic wiring for a 555 in astable mode is pretty straightforward; +5 volts |-----+ +-|-----|-+ +-Res.1-------| 8 4 | | | | |---...---| 7 3 |------> to Base of BJ Transistor Res. 2 | | | +----| 6 "555" | | | | | +--------+----| (...) (27 years ago, 26-Nov-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.810)
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| | Re: tracking an IR beacon
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| The phase difference seen by the sensors would be tiny at any practical frequency. Assume that you have the sensors a distance, D, apart and facing 'forward' on the robot. If there is a transmitting source at 90 degrees to the forward direction, the (...) (27 years ago, 8-Dec-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.807)
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| | Re: tracking an IR beacon
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| (...) I confirm what David is saying! Once i worked on some kind of beacon using an PLL to find its frequency (we used a lm567) and it couldn't work properly due to the response time of the PLL. An alternate solution was to replace the PLL by a (...) (27 years ago, 7-Dec-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.807)
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| | tracking an IR beacon
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| Hello all - My goal: I'm trying to determine the feasibility of tracking an IR source with my Handy Board. My initial scheme calls for using two IR detectors (the ones with all the internal filters, etc, to provide a clean 5V output upon detection (...) (27 years ago, 6-Dec-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.807)
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| | Re: tracking an IR beacon
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| (...) Hmmm...mmm... welllll.. if you are planning to use the GPUI series or equiv. as your detectors.. I think you may run into problems with attempting to detect critical time information about the modulated waverform. Namely, and I'm no expert on (...) (27 years ago, 7-Dec-97, to lugnet.robotics.handyboard)
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frequency
(score: 1.807)
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