Subject:
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Re: Polaroid 6500 Sonar Problem
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Tue, 9 Mar 1999 15:32:56 GMT
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Original-From:
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Chen Yung Hsu <[hsu3@cooper]AntiSpam[.edu]>
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Viewed:
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3297 times
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I would also like to know about this. please respond.
=) chen
On Mon, 8 Mar 1999, rmtmd wrote:
> I'm having difficulty getting my sonar rangefinder to work properly.
>
> I've got a fully operational Handy Board with a fully operational
> Expansion Board plugged into it (both purchased assembled from Gleason
> and used extensively already without difficulty). I've soldered the nine
> pin flex cable adapter into the appropriate place on the top of the
> expansion board, and I've got the flex cable plugged into it and into the
> adapter on the sonar driver board I purchased assembled from Wirz. I've
> soldered a solid core wire to pad J12 on the expansion board and plugged
> the other end into the digital input numbered "7" on the Handy Board
> itself (first hole on right in the single row header next to the power
> expansion header).
>
> Running Interactive C 3.1 (commercial version from Newton Labs), I loaded
> "sonar.c" (Fred Martins' driver code) to test everything. When I invoked
> the "sonar_display();" function, I heard the transducer clicking rapidly.
> The LCD display updated in sync with the clicks. So far so good.
>
> The display, however, did not change significantly, when, holding the
> transducer by it's wires, not by its body, I pointed it at flat surfaces
> at varying distances from it ranging from a few feet to five or ten feet
> away. I kept getting a number around 1450 to 1460 on the LCD as the
> value of "result," which holds the result of the call to the ranging
> function, "sonar_closeup();". Occasionally numbers up to 1800 or so
> flash on momentarily, but for the most part the numbers being
> continuously updated run in the 1450s to 1460s.
>
> I've tried substituting "sonar_sample();" for the call to
> "sonar_closeup();" in the "sonar_display();" function's body, to no
> avail. If the returned value on the LCD represents the number of half
> milliseconds elapsed, then, I seem to be reading a constant distance of
> about .3 feet (1450 ticks / 2000 ticks/ms = 0.725 ms; 0.725 ms / 2 = .362
> ms, or the time for sound to travel ONE way to target; .362 ms / 1.1
> ft/ms {speed of sound} = .33 ft).
>
> HELP!
>
> Ross M. Tonkens, M.D.
> Medical Director
> Primary Care of Nevada
> 100 North Green Valley Parkway
> Suite 240
> Henderson, NV 89014
>
> 702 914-7120 VOICE
> 702 914-7129 FAX
>
> I've reproduced Fred Martin's driver code below rather than referring
> everyone to the URL where I downloaded it.
>
> /*
> sonar.c
> Polaroid 6500 routines for Handy Board / Interactive C
> by Fred Martin, fredm@media.mit.edu
> Sat Nov 22 13:57:35 1997
>
> echo signal is connected to tic3/pa0;
> init signal is pd5 (SS);
> binh signal is pd4 (SCK)
> */
>
> void sonar_init() {
> bit_set(0x1009, 0x30); /* ddrd */
> bit_set(0x1021, 1); /* at tctl2, */
> bit_clear(0x1021, 2); /* set tic3 for rising edge */
> }
>
>
> int sonar_sample() {
> int start_time;
>
> poke(0x1023, 1); /* clear tic3 flag */
>
> start_time= peekword(0x100e); /* capture start time */
> bit_set(0x1008, 0x20); /* trigger pulse */
>
> while (!(peek(0x1000) & 0x1)) { /* wait until receive echo */
> if ((peekword(0x100e) - start_time) < 0) {
> /* if too much time has elapsed, abort */
> bit_clear(0x1008, 0x20);
> return -1;
> }
> defer(); /* let others run while waiting */
> }
>
> bit_clear(0x1008, 0x20); /* clear pulse trigger */
>
> return peekword(0x1014) - start_time; /* tic3 has time of echo */
> }
>
> int sonar_closeup() {
> int start_time;
>
> poke(0x1023, 1); /* clear tic3 flag */
> start_time= peekword(0x100e);
> poke(0x1008, 0x20);
>
> while ((peekword(0x100e) - start_time) < 1000);
>
> bit_set(0x1008, 0x30); /* turn on BINH */
>
> while (!(peek(0x1000) & 0x01)) {
> if ((peekword(0x100e) - start_time) < 0) {
> /* if too much time has elapsed, abort */
> bit_clear(0x1008, 0x30);
> return -1;
> }
> defer();
> }
>
> bit_clear(0x1008, 0x30);
>
> return peekword(0x1014) - start_time; /* 0x1014 is tic3 */
> }
>
> void sonar_display() {
>
> int result;
>
> sonar_init();
>
> while (1) {
> result= sonar_closeup();
> if (result != -1) printf("%d\n", result);
> else printf("*******\n");
> msleep(50L);
> }
> }
>
>
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Message is in Reply To:
 | | Polaroid 6500 Sonar Problem
|
| I'm having difficulty getting my sonar rangefinder to work properly. I've got a fully operational Handy Board with a fully operational Expansion Board plugged into it (both purchased assembled from Gleason and used extensively already without (...) (28 years ago, 9-Mar-99, to lugnet.robotics.handyboard)
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