looking for Eli Kolberg or Seattle Robotics folks
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We have sent this email to two different email addresses referenced
on the Seattle Robotics website and the message has bounced. We
are specifically trying to get in touch with Eli Kolberg, who designed
the circuit we are writing about. Here is a link to that circuit, which
is a microphone frequency sensor:
http://www.seattlerobotics.org/encoder/200112/elik.htm
Here is our message for Eli, or, if anyone else is familiar with the
circuit and wants to assist:
We are graduate students who are doing a project with robots. Our
robots use the Homework Board CPU from Parallax.
http://www.parallax.com/detail.asp?product_id=28158
We found your documentation about the microphone frequency sensor
on the web, and we are trying to use it to implement tone recognition
between our robots. We used most of the components in your parts
list except for the diodes and one resistor. We used IN4001 diodes
instead of IN4002 diodes, because we were told that they are almost
the same. We used a 330 ohm resistor instead of a 300ohm resistor
(R9 in your schematic) because we couldn't find a 300 ohm resistor.
The output of our circuit is a little bit different as would be expected.
When we used a 2 KHz frequency, the voltage we got was exactly like
using a 4 KHz frequency. We tried to use an analog to digital chip
(ADC0831) to convert the voltage to a number, but we found that even
when we were using the same frequency, the number we got would
only change when the distance of the speaker and microphone
changed. We have to put the speaker very close to the microphone
(within 5 inches) in order for the microphone to sense the tone.
Another problem is, when the frequency is lower than 2 KHz, or higher
than 4 KHz the mic can't sense it.
Can you give us some suggestions on what we could do to solve the
problem?
We appreciate your time and your suggestions, and value your input.
Thanks!
The Robot 4 Team
---
The Robo4 Team:
Tony Chang, Marie Masoumi, Lizhen Yang, Sabrina L. Nelson
Graduate Students
Masters in Multimedia Program
California State University @ Hayward
on the Seattle Robotics website and the message has bounced. We
are specifically trying to get in touch with Eli Kolberg, who designed
the circuit we are writing about. Here is a link to that circuit, which
is a microphone frequency sensor:
http://www.seattlerobotics.org/encoder/200112/elik.htm
Here is our message for Eli, or, if anyone else is familiar with the
circuit and wants to assist:
We are graduate students who are doing a project with robots. Our
robots use the Homework Board CPU from Parallax.
http://www.parallax.com/detail.asp?product_id=28158
We found your documentation about the microphone frequency sensor
on the web, and we are trying to use it to implement tone recognition
between our robots. We used most of the components in your parts
list except for the diodes and one resistor. We used IN4001 diodes
instead of IN4002 diodes, because we were told that they are almost
the same. We used a 330 ohm resistor instead of a 300ohm resistor
(R9 in your schematic) because we couldn't find a 300 ohm resistor.
The output of our circuit is a little bit different as would be expected.
When we used a 2 KHz frequency, the voltage we got was exactly like
using a 4 KHz frequency. We tried to use an analog to digital chip
(ADC0831) to convert the voltage to a number, but we found that even
when we were using the same frequency, the number we got would
only change when the distance of the speaker and microphone
changed. We have to put the speaker very close to the microphone
(within 5 inches) in order for the microphone to sense the tone.
Another problem is, when the frequency is lower than 2 KHz, or higher
than 4 KHz the mic can't sense it.
Can you give us some suggestions on what we could do to solve the
problem?
We appreciate your time and your suggestions, and value your input.
Thanks!
The Robot 4 Team
---
The Robo4 Team:
Tony Chang, Marie Masoumi, Lizhen Yang, Sabrina L. Nelson
Graduate Students
Masters in Multimedia Program
California State University @ Hayward
Comments
>are specifically trying to get in touch with Eli Kolberg, who designed
>the circuit we are writing about. Here is a link to that circuit, which
>is a microphone frequency sensor:
>
>http://www.seattlerobotics.org/encoder/200112/elik.htm
Hi team,
Referring to the circuit URL above, the LM2917 needs a resistor
connected from pin 1 to ground. Use something like 1kohm. That
provides a path for the comparator bias current. That might explain
why you had to bring the sound so close to the microphone to make it
work, and other funny behavior.
If you have an AC voltmeter, connect it to the output of the LM386 to
verify that you are receiving and amplifying a good signal.
Plugging parts values from the schematic into the frequency/voltage
formula, I come up with 1.35 volts per kilohertz, which is a bit more
that the 1 volt per khz he graphed. That may have to do with
component tolerances and construction techniques.
By the way, you are okay to use the 4001 diodes and maybe the 330 ohm
resistor. I suggest you use your voltmeter to measure the DC voltage
on pins 5 and 6 of the LM2917 with respect to ground. If the voltage
is less than 7.5 volts, then replace your 330 ohm resistor with a
lower value, say 220 ohm. The LM2917 has a built-in 7.5 volt zener
regulator.
I would probably do the circuit a little differently. The LM2917 chip
works fine on 5 volts, just that it can't swing its output higher
than 3 volts on a 5 volt supply. I'd power the LM2917, pins 5 and 6
directly from the 5 volt supply, and leave out the 7660 charge pump.
Change C4 from 1800 pf to 1000 pf, and leave R2 and C5 as they are.
That should give an output of 0.5 volt per kilohertz up to about 6
khz.
Good luck,
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
>We are graduate students who are doing a project with robots. Our
>robots use the Homework Board CPU from Parallax.
>http://www.parallax.com/detail.asp?product_id=28158
>
>We found your documentation about the microphone frequency sensor
>on the web, and we are trying to use it to implement tone recognition
>between our robots. We used most of the components in your parts
>list except for the diodes and one resistor. We used IN4001 diodes
>instead of IN4002 diodes, because we were told that they are almost
>the same. We used a 330 ohm resistor instead of a 300ohm resistor
>(R9 in your schematic) because we couldn't find a 300 ohm resistor.
>
>The output of our circuit is a little bit different as would be expected.
>When we used a 2 KHz frequency, the voltage we got was exactly like
>using a 4 KHz frequency. We tried to use an analog to digital chip
>(ADC0831) to convert the voltage to a number, but we found that even
>when we were using the same frequency, the number we got would
>only change when the distance of the speaker and microphone
>changed. We have to put the speaker very close to the microphone
>(within 5 inches) in order for the microphone to sense the tone.
>Another problem is, when the frequency is lower than 2 KHz, or higher
>than 4 KHz the mic can't sense it.
>
>Can you give us some suggestions on what we could do to solve the
>problem?
>
>We appreciate your time and your suggestions, and value your input.
>
>Thanks!
>
>The Robot 4 Team
>
>---
>
>The Robo4 Team:
>Tony Chang, Marie Masoumi, Lizhen Yang, Sabrina L. Nelson
>Graduate Students
>Masters in Multimedia Program
>California State University @ Hayward
>
>
>
>To UNSUBSCRIBE, just send mail to:
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>Subject and Body of the message will be ignored.
>
>
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I'll send
it to the teammate who is building the audio circuit and write back if there are
more
questions.
Sabrina
--- In basicstamps@yahoogroups.com, Tracy Allen <tracy@e...> wrote:
> >We
> >are specifically trying to get in touch with Eli Kolberg, who designed
> >the circuit we are writing about. Here is a link to that circuit, which
> >is a microphone frequency sensor:
> >
> >http://www.seattlerobotics.org/encoder/200112/elik.htm
>
>
> Hi team,
>
> Referring to the circuit URL above, the LM2917 needs a resistor
> connected from pin 1 to ground. Use something like 1kohm. That
> provides a path for the comparator bias current. That might explain
> why you had to bring the sound so close to the microphone to make it
> work, and other funny behavior.
>
> If you have an AC voltmeter, connect it to the output of the LM386 to
> verify that you are receiving and amplifying a good signal.
>
> Plugging parts values from the schematic into the frequency/voltage
> formula, I come up with 1.35 volts per kilohertz, which is a bit more
> that the 1 volt per khz he graphed. That may have to do with
> component tolerances and construction techniques.
>
> By the way, you are okay to use the 4001 diodes and maybe the 330 ohm
> resistor. I suggest you use your voltmeter to measure the DC voltage
> on pins 5 and 6 of the LM2917 with respect to ground. If the voltage
> is less than 7.5 volts, then replace your 330 ohm resistor with a
> lower value, say 220 ohm. The LM2917 has a built-in 7.5 volt zener
> regulator.
>
> I would probably do the circuit a little differently. The LM2917 chip
> works fine on 5 volts, just that it can't swing its output higher
> than 3 volts on a 5 volt supply. I'd power the LM2917, pins 5 and 6
> directly from the 5 volt supply, and leave out the 7660 charge pump.
> Change C4 from 1800 pf to 1000 pf, and leave R2 and C5 as they are.
> That should give an output of 0.5 volt per kilohertz up to about 6
> khz.
>
> Good luck,
>
> -- regards,
> Tracy Allen
> electronically monitored ecosystems
> mailto:tracy@e...
> http://www.emesystems.com
>
>
> >We are graduate students who are doing a project with robots. Our
> >robots use the Homework Board CPU from Parallax.
> >http://www.parallax.com/detail.asp?product_id=28158
> >
> >We found your documentation about the microphone frequency sensor
> >on the web, and we are trying to use it to implement tone recognition
> >between our robots. We used most of the components in your parts
> >list except for the diodes and one resistor. We used IN4001 diodes
> >instead of IN4002 diodes, because we were told that they are almost
> >the same. We used a 330 ohm resistor instead of a 300ohm resistor
> >(R9 in your schematic) because we couldn't find a 300 ohm resistor.
> >
> >The output of our circuit is a little bit different as would be expected.
> >When we used a 2 KHz frequency, the voltage we got was exactly like
> >using a 4 KHz frequency. We tried to use an analog to digital chip
> >(ADC0831) to convert the voltage to a number, but we found that even
> >when we were using the same frequency, the number we got would
> >only change when the distance of the speaker and microphone
> >changed. We have to put the speaker very close to the microphone
> >(within 5 inches) in order for the microphone to sense the tone.
> >Another problem is, when the frequency is lower than 2 KHz, or higher
> >than 4 KHz the mic can't sense it.
> >
> >Can you give us some suggestions on what we could do to solve the
> >problem?
> >
> >We appreciate your time and your suggestions, and value your input.
> >
> >Thanks!
> >
> >The Robot 4 Team
> >
> >---
> >
> >The Robo4 Team:
> >Tony Chang, Marie Masoumi, Lizhen Yang, Sabrina L. Nelson
> >Graduate Students
> >Masters in Multimedia Program
> >California State University @ Hayward
> >
> >
> >
> >To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> >from the same email address that you subscribed. Text in the
> >Subject and Body of the message will be ignored.
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/