Most PDAs and Laptops these days have Bluetooth radios, so if you're looking for a non-tethered connection, Bluetooth is a good solution if you're connection distance is less than about 35-40 feet (indoors), or better (outdoors).
The Serializer also supports XBEE radios, which might be a good solution for you, because they are wireless too. If the Bluetooth radio doesn't have a far enough reach (distance between your shed and your house), then you can use XBee radios. These are nice in that you can add additional XBee radios between the Serializer, and your PC, to work as relays. In addition, for the XBee radios to work, you can use an RS-232 Serial to XBee board that plugs into your PC, and you can have an almost instant connection w/ the Serializer (fitted w/ a XBee radio). You will have to perform a little bit of configuration for each XBee radio, and there's a good article on how to do this in I believe Circuit Cellar magazine a few months back.
Hey Ringo, what issue of Circuit Cellar magazine featured the article using distributed XBee radios being used to gather data around the author's home (e.g. pool temp, outside temp, etc.)?
You will need to purchase the XBee radios directly from MaxStream. They wouldn't give us enough of a cost break to justify selling them, hence the reason we send customers to MaxStream.
I doubt Serial or USB will work for you since your shed is probably quite a ways from your home, outside.
You asked about timing > 1ms. the sonar timing functions look for a rising edge then time how long until it sees the falling edge. You can configure the serializer to return this value in uS. Would this work for you?
For the PWM question. the frequency of the pwm is fixed at 10 khz. If you set a pwm value of 1 then there is voltage applied 1% of the time. A pwm value of 50 means 50% of the time (square wave), etc. If you filter this output with a large capacitor then you will get an analog voltage out = to the percentage mentioned above. So if you use a 9.6V battery and a pwm value of 50 you will get approximately 4.8V. I say approximately because Im sure there is some loss in the H-bridge, but it should be a linear drop so you could account for it.
Does this help?
Ringo