Search found 80 matches

by mikeb
Mon Mar 29, 2004 8:22 pm
Forum: General Discussion
Topic: ultra sonic xmitter and rec.
Replies: 2
Views: 1149

ultra sonic xmitter and rec.

hi guys i tested the transmitter at the output to the transducer with a frequency counter and i measured a squarewave at 39.996 khz i think this might be acurate enough that the reciever should not suffer so much as far a recieving the signal. i also measured the signal at the reciever when its dete...
by mikeb
Sat Mar 27, 2004 7:34 pm
Forum: General Discussion
Topic: ultrasonic motion detector
Replies: 5
Views: 1370

ultrasonic motion detector

i built a ultra sonic motion detector from a article from the poptronics website. the article says the unit should measure motion from 4 to 7 meters away but im only able to measure motion up to a distance of about a inch to a inch an a half. i was wanting to know if i increase the current flow thru...
by mikeb
Sat Mar 20, 2004 9:29 pm
Forum: General Discussion
Topic: help with variable coils
Replies: 3
Views: 1249

help with variable coils

does any one know how to identify variable coils. i have about 15 variable colis that have no identication other then the color of the coil itself, some are yellow, some brown, some green a few are orange and some grey im wondering can the inductance of these coils be identified by color.
by mikeb
Fri Mar 19, 2004 8:54 pm
Forum: General Discussion
Topic: microcontroller to ac pwer line to ac controlled devices
Replies: 1
Views: 860

microcontroller to ac pwer line to ac controlled devices

hi im trying to find out whether you can transfer data signals from a micro controller over the ac power lines in a house to control the electrical outlets as far as turning them on and off without using a relay. im basically wanting to control the electrical outlets in a house with on off signals, ...
by mikeb
Sun Feb 08, 2004 11:03 pm
Forum: General Discussion
Topic: unipolar stepper motor questions
Replies: 3
Views: 1478

Re: unipolar stepper motor questions

this is the website for the schematic page 5www.elabinc.com
by mikeb
Sun Feb 08, 2004 11:01 pm
Forum: General Discussion
Topic: unipolar stepper motor questions
Replies: 3
Views: 1478

Re: unipolar stepper motor questions

this is the website for the shecmaticede1200/page5 of data sheet
by mikeb
Sun Feb 08, 2004 10:46 pm
Forum: General Discussion
Topic: unipolar stepper motor questions
Replies: 3
Views: 1478

unipolar stepper motor questions

thanks guys for the good suggestions about the lcd. i havent yet tryed anything been busy with a stepper project im workin on as well, but i will let you guys know what the outcome is as soon as i get a chance to install the diode an cap. my question now is on the subject of stepper motors. im tryin...
by mikeb
Sat Feb 07, 2004 3:54 pm
Forum: General Discussion
Topic: ds12887a rtc
Replies: 0
Views: 739

ds12887a rtc

does any one know how to interface the dallas 12887a rtc to a microcontroller. i salvage the chip from an old pc an i want to interface connect it to a microcontroller. i want to use a 8 bit microcontroller bi directional port to input and read data from the rtc. i have the circuit connected but it ...
by mikeb
Mon Feb 02, 2004 6:04 pm
Forum: General Discussion
Topic: circuit bypass question
Replies: 3
Views: 1145

circuit bypass question

i have a circuit that includes an lcd display, a microphone as well as a speaker, when i talk on the mic, and send audio to the speaker the lcd display starts to shimmer and the backlit gets dimmer. does any one know what may be causing the audio to be reflected on the lcd display.
by mikeb
Wed Jan 28, 2004 11:18 am
Forum: General Discussion
Topic: lcd help
Replies: 2
Views: 1090

lcd help

Does anyone know the starting line addresses for a 4 line by 16 character lcd display. I know line #1 is at $80 and line #2 is at $C0 I need the address for lines 3 and 4. Thanks for any help you can give.
by mikeb
Thu Jan 22, 2004 1:01 pm
Forum: General Discussion
Topic: help needed with a super cap
Replies: 2
Views: 862

help needed with a super cap

hello guys im trying to connect a super cap to a micro as the backup power source for ram. my problem is as soon as the power fails or is disconnected the super cap discharges rather quicky in maybe 30 seconds giving me back up power for that long. is there anyone knowing how i can build circuitry t...
by mikeb
Tue Dec 30, 2003 10:26 pm
Forum: General Discussion
Topic: Lookin for door lock ideas
Replies: 2
Views: 881

Lookin for door lock ideas

does any one have any suggestions or know of a website that has solenoid type actual door lockin mechanisms, or something similar. im wanting to build a lock that is micro-controller controlled that is of the soleniod type or something similar. any suggestions will be most appreciated.
by mikeb
Thu Dec 25, 2003 8:13 pm
Forum: General Discussion
Topic: rtc question to bodgy
Replies: 1
Views: 716

rtc question to bodgy

i basically want to read the data and store it in a memory byte one for each unit day month date yr etc.
by mikeb
Thu Dec 25, 2003 6:38 pm
Forum: General Discussion
Topic: ds1302 rtc
Replies: 1
Views: 747

ds1302 rtc

does any one have knowledge about the ds1302 rtc im wanting to know if this ic after powerup needs to be set with proper date time yr month an hour data. also the data sheet says the date time yr month an hour is in bcd format in there prespective registers so im assuming that no decoding is needed ...
by mikeb
Thu Dec 11, 2003 9:34 pm
Forum: General Discussion
Topic: crystal oscillator questions
Replies: 4
Views: 1398

crystal oscillator questions

does any one have any advice on using a 4 pin 1mhz crystal oscillator, to produce a fix output frequency at 1mhz. i was wanting to know if these are as simply to use as they appear. by just applying the proper supply voltage does this clock oscillator start outputting pulses at the fix frequency of ...