Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: izua on June 21, 2008, 07:38:11 PM
-
Hey, does anyone has a schematic for something similar to this (http://www.sparkfun.com/commerce/product_info.php?products_id=7813) ?
I want to brew one myself. I'd appreciate if the frequency can be easily changed. Baud rate is not a problem (1200 or even 600 is fine with me).
What I'm intending to do is a pair of transceivers, on different frequencies. Let's say a very weak form of fullduplex communication :P
-
It was against the law and most likely still is to build something like that yourself. Anything DIY project that can transmitter over 50 ft is a no no. I am always the 1st to say build it yourself but not this time, just buy one.
Hey, does anyone has a schematic for something similar to this (http://www.sparkfun.com/commerce/product_info.php?products_id=7813) ?
I want to brew one myself. I'd appreciate if the frequency can be easily changed. Baud rate is not a problem (1200 or even 600 is fine with me).
What I'm intending to do is a pair of transceivers, on different frequencies. Let's say a very weak form of fullduplex communication :P
-
I'm not living in the states. Radio regulations are more relaxed here. There are also open frequencies, like the ubiquitos PMR446. There's a simple reason I want to build one myself: configurability. That's never cheap if going for industrial manufacture.
PMR466, for example, has no range restriction. There are another bunch of frequencies that have this. And there are also the aeromodeling and car-modeling frequencies. What I'm trying to achieve is a basic duplex communication with my bot.
I think this is a good start for a thread where someone with good analogic skills can explain the principles of a single transmitter-receiver pair modulating digital data. Things like bandwidth, frequency, fourier analysis would come in handy here. Ideally, we should come up with a system that can be configured for our needs (frequency regulations, wanted power, performance, etc). I'll be happy to make all the simulations related to this, if someone explains the idea :P
-
hmmmm I'm confused why the title says 'analog radio' but they you specify baud rate (a digital thing) :P
http://www.google.com/search?q=how+to+make+a+transistor+radio
Your signal is then sent to the gate of the transistor for the transmitter.
And you use an ADC or an edge detector for the receiver.
(just google it all up for more info)
-
whoops i think i ment digital. the principle of operation is still analog, anyway.
i'm talking about ook, or ack modulation, f.i.