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 | | Re: L293D Piggybacking
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| Yes, most people have found that this works. -Fred -- This message was composed using Articulate Systems' PowerSecretary, a Macintosh-based speech-to-text dictation system. Please forgive any sloppiness in the formatting. Thanks. -Fred In your (...) (28 years ago, 10-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.062)
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fred
(score: 0.061)
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| | Re: expansion board schematic posted
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| It is largely a space issue, not only for chips but connectors. It definitely would be feasible to remove one of the analog muxes and substitute an output latch in its place. Then the specs would be 8 general purpose, 4 hi impedance, 4 LEGO analog (...) (28 years ago, 7-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.061)
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| | expansion board schematic posted
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| Hi all, I have put on the web site a schematic drawing of the expansion board as it currently stands. I would appreciate any comments regarding the feature set. In particular, I'm not sure what's best to do with the two digital outputs: * just (...) (28 years ago, 7-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.061)
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| | blown L293's
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| Bill, I think the moral of the story is: DO NOt use 3v motors with the Handy Board. They draw too much current. Use motors rated at least 6v, even that can be a problem. I should put this in the manual somewhere... See (URL) to buy more L293's. (...) (28 years ago, 6-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.061)
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| | Re: QRD1114?
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| Digikey. call 1 800 DIGI KEY. add 'QT-ND' to the part number and you get the digikey catalog #. -fred In your message you said: (...) (28 years ago, 5-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.061)
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| | Re: IR sensor question
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| As illustrated in the hb manual, the QRD and QRB sensors do NOT use modulated IR light. the sensors as wired just turn on the IR emitter like a little light bulb, and the received sensor value is a combination of reflected IR light and general (...) (28 years ago, 6-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.061)
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| | Re: Downloading problems
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| The memory circuit is probably flaky, or, you zapped a 6811 address line output. If you haven't already tried, swap the 6811 with a known good one. If that doesn't work, examine the ram chip addr, data bus, and select signals with a logic probe when (...) (28 years ago, 5-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.061)
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| | Re: Sample bump sensor routine
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| whether you use analog or digital ins, you don't need the 47k pullup because the hb already has one. just wire the signal line to ground through the normally open switch. bill, i suggest you write your program without using the multitasking (...) (28 years ago, 4-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.061)
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| | expansion board
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| Fred, It seems to me that the first thing most people want to add to their robots that is not supported on the handyboard itself, is IR collission detection. How about including a modulator and driver for IR LED's, and a detector and demodulator (...) (28 years ago, 14-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | Re: Buncha bouncebacks
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| Sorry, there is nothing I can do about this short of compiling, installing, and configuring brand new mail list software from scratch. The mail list SW my lab provides is very primitive and can't do anything intelligent with bounces. I don't really (...) (28 years ago, 30-Jan-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | Re: Is 18V correct?
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| this is correct. normal dc adapters are unregulated and there is a reciprocal relation between voltage and current. when you just plug it in and and measure voltage, current is 0 and hence voltage is higher than the spec. if you draw the rated 500 (...) (28 years ago, 29-Jan-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | Re: -POWER-GLITCH-
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| Make sure your downloader is configured to download "pcode_hb.s19" and not any of the other variants (eg pcode_r22.s19). Avard, please send me an email and let me know if this solves your problem. -Fred In your message you said: (...) (28 years ago, 26-Jan-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | Re: memory not remembering...
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| Ben -- the pin 27 R/W line of the RAM should be connected directly to the R/W line of the 6811. I don't remember the pin # off hand -- it's 7 i think -- but just check the schematic. check the continuity first on the board. if that's ok, then check (...) (28 years ago, 26-Jan-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | Re: expansion board schematic posted
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| Hi Fred The "new" spec sound's great ! I'd also like to see a bit more digital I/O on any expansion board, and the extra 8 CMOS outputs are just what I (we) need. Thanks Scott (...) Martin'" <fredm@media.mit.edu> (...) (28 years ago, 10-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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fred
(score: 0.060)
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| | (no subject)
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| You are unsubscribed. For future reference, the way to unsubscribe is to write to me. fredm@media.mit.edu. -Fred In your message you said: (...) (28 years ago, 24-Jan-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | Re: Problems with downloading
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| Tom: Your tests, specifically the fact that the HB's PWR LED comes on after download fails, demonstrate conclusively that the HB can *receive* data from your PC. This proves that the downloading software is able to open the serial port properly, and (...) (28 years ago, 23-Jan-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | Re: IC loop
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| Hi Wade, You can use the "seconds()" function which reports elapsed time, plus a variable to keep track of when the loop should end: void main() { float end_time; end_time= seconds() + 20.; /* go for 20 seconds */ while (seconds() < end_time) { /* (...) (28 years ago, 23-Jan-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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| | RE: expansion board schematic posted
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| I've got one comment "balance". The expansion board adds 24 new inputs and only 6 new outputs. Perhaps I'm atypical but I don't need any more inputs to the handy board, I've got those aplenty, but I'm screaming for outputs to control other parts of (...) (28 years ago, 7-Feb-97, to lugnet.robotics.handyboard)
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fred
(score: 0.060)
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