Subject:
|
electronics question please help
|
Newsgroups:
|
lugnet.robotics.handyboard
|
Date:
|
Mon, 22 Feb 1999 21:18:08 GMT
|
Original-From:
|
Bob Kelly <rkelly@firstunion-/spamless/reit.com>
|
Viewed:
|
859 times
|
| |
|
|
Hello all,
I hope there is a simple answer for this...
I have attempted to build the circuit that will allow IR object detection
using the Sharp IR detector module and a pair of "high output" infrared
LEDs. The circuit I built was the one from "Mobile Robots - Inspiration to
Completion, 2nd ed."
The circuit calls for, among other things, a 74HC04 inverter. I obtained all
the components from my local Radio Shack. The Inverter that I got is
actually a 74HCT04 and the IR receiver was the same part number specified
with the exception of a "B" suffix (hopefully to denote vertical mount Vs.
horizontal mount). I implemented a slightly modified version of code to read
the sensor that was based heavily on the info given in the book (I timed the
LED pulse as required).
Obviously, or I wouldn't be asking questions, the thing doesn't work. The
LEDs are working (saw 'em through the video camera) and there is power to
the Detector (yes, I grounded the case). I wired everything painstakingly
per the diagram but I was wondering if it is necessary to supply steady
voltage to the inverter (I have not, and the book didn't tell me to.) I did
ground the inverter however.
Is the supply of voltage to the 74HCT04 assumed in the diagram or is it
likely I left something else out? Also, specific pin assignments for
connection to the inverter were not given so I carefully wired them
according to the pin out detail on the inverter package pin assignments and
symbology. Is the 74HCT04 not interchangeable with the 74HC04?
Are there any other things I should be aware of if trying to implement this
circuit on a Handy Board?
I am new at electronics and I thought this might be a nice "get my feet wet"
starter project. I don't have access to fancy testing equipment so any help
at all would be greatly appreciated. I apologize if this question is a
little on the basic side.
Thanks again,
Bob K.
|
|
Message has 4 Replies:
 | | Re: electronics question please help
|
| (...) Been there, done that! Funny. I bought almost all the same stuff from my local shack. Writting the software was the easy part ;^). (...) I've supplied some power to the inverter, yes. I'm assuming it's mandatory to have the inverter actually (...) (26 years ago, 22-Feb-99, to lugnet.robotics.handyboard)
| | | Re: electronics question please help
|
| The modulation frequency of the IR diodes must match the sensor (depending on exact part number, around 38 KHz) within +/- 3 KHz. As you move away from the center frequency, detection drops off sharply. Are you able to confirm the modulation (...) (26 years ago, 23-Feb-99, to lugnet.robotics.handyboard)
|
6 Messages in This Thread:
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
