Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: Arthi Selva on July 03, 2011, 03:02:47 PM
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Hi.
I am constructing a sound tracking robot for my FYP. 4 microphones facing 4sides receives sound and P16F877A as controller and 2servo motors as output. The microphone will receive sound from sources.. the robots have to move towards the highest frequency sound.. i am really finding for circuit diagram for this project. If u can guide me to find a circuit for this. Thank you.
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You're going to have to be more specific. What kind of microphones will you be using?
Also, I think the programming is going to be harder than the circuit itself.
You're probably not going to find an exact circuit diagram out there that you can use. You will probably have to make one up yourself.
Anyway, as for the real help, check out this thread. The person is basically doing the exact same thing as you and Soeren has some great advice.
http://www.societyofrobots.com/robotforum/index.php?topic=13998.0 (http://www.societyofrobots.com/robotforum/index.php?topic=13998.0)
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Actually i am using 4 condenser microphones. I have a circuit for a single microphone. so if i want to input signals from the microphones to PORTA of the PIC, do i have to make 4 circuits for the four microphones? and the output is to 2 servo motors. can i connect them directly to the output ports or should i make any circuits for the servo also?
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The answer about the servo connections is in the Robot Tutorials found above (under the SoR page title).
How would you use one microphone amplifier circuit work for four independent microphones?
Also, I think the programming is going to be harder than the circuit itself.
If you are not experienced with assembler language programming on a PIC then yes, the programming will be hard.
It is best to break the program into smaller tasks and get each working. For example, get the code working to control one servo, then add code to control two servos.
Separately write code to to measure the amplitude of a microphone input, then two mics and a compare.
Then finally put all the code pieces together.
The ADC's on a 16F877 are not that fast at conversion and may not be able to digitize the AC waveform from the microphone so that the code can calculate the frequency. Instead you may need to create a circuit that produces a DC signal that is proportional to the frequency of buzzer heard by the microphones.
Another way is to ensure that the output from the microphone amplifier is large enough to provide clean digital logic levels. Then use the PORTB IOC to measure the period of each input (1/period = frequency).
This part of your project will probably be the most work. The servo control part should be relativity easy since many people have done this and there are a number of code samples on the web.
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Actually i am using 4 condenser microphones. I have a circuit for a single microphone. so if i want to input signals from the microphones to PORTA of the PIC, do i have to make 4 circuits for the four microphones? and the output is to 2 servo motors. can i connect them directly to the output ports or should i make any circuits for the servo also?
As waltr said, you would need 4 circuits for 4 microphones.
Here is the servo tutorial. It's really straightforward. It's not that you need to make circuits for them, but you can't just hook them up and expect to say "Go forward" and it work. You WILL need to provide a regulated power source for them though. So I guess that could be a circuit for them... :P
http://www.societyofrobots.com/actuators_servos.shtml (http://www.societyofrobots.com/actuators_servos.shtml)