Wireless Transmitter Suggestions

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pixel2001n
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Wireless Transmitter Suggestions

Post by pixel2001n » Mon Aug 04, 2008 11:54 am

I've been using a Bluetooth Audio Transmitter to get data from an analog sensor rotating at several thousand RPMs (where running a wire would be difficult). The transmitter is a Com One BSTR002A Universal Bluetooth Stereo Transmitter, for those that are curious. It gives a great frequency response up to about 17kHz. The only problem is that it won't send the static (aka DC) component of my sensor's signal. Up until now, this hasn't been an issue because I've been mainly interested in the sensor's dynamic response. But now I'd like to start looking at its entire response.

So, my question is: does anyone here know of a good analog data transmitter that can be easily received and recorded on a computer (it doesn't have to be Bluetooth) which will send the DC component? I can live with a lower bandwidth, but I'd like at least 4kHz (10kHz is ideal).

Small form factor and ease of integration are more important than cost, but I'd like to keep the price under about $500.

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philba
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Post by philba » Mon Aug 04, 2008 2:13 pm

the classical solution is to use a microcontroller to convert analog signal to digital and transmit that. Typically, a microcontroller plus a transmitter would do the trick. How much experience with microcontrollers do you have? (I'm guessing little or you wouldn't be asking).

You might look at zigbee remote monitors. I know crossbow and others are working in that area. http://www.xbow.com/Home/wHomePage.aspx I have no idea if it meets your needs, though.

Engineer1138
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Post by Engineer1138 » Mon Aug 04, 2008 2:34 pm

I think the Roving Networks RN24 has an analog input. I am currently working with the RN41, but it's all digital. If I'm wrong about the RN24, take a look at the Parani units from Sena, I know one or the other has a unit that has analog input.

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jwax
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Post by jwax » Tue Aug 05, 2008 2:21 pm

Perhaps a voltage-to-frequency converter? For example, with a 0-5 volt input, the output goes from 5 KHz to 10 KHz. The frequency-to-voltage converter on the receiving end converts the 5-10 KHz back into 0-5 volts.

pixel2001n
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Post by pixel2001n » Tue Aug 05, 2008 4:40 pm

Zigbee is an interesting choice. I'm still looking in to it. The range is much higher than we need and I'm not sure exactly what the ATD bandwidth really is on the crossbow modules. I'll continue to look into it, though.

A voltage to frequency converter would be great for what we want to do. Is there a simple way to do it?

I'd like to learn more about microcontrollers. I've used a Motorola HCS12 before, but that's about the extent of my experience. The problem would be finding one that's fast enough to sample and transmit at 10kHz with a development environment simple and complete enough for the inexperienced. Anyone have any recommendations?

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