RadioScope Shortcomings / Potential Improvements

Back to table of contents.


Shortcomings

In my original proposal for this project, I planned to attach analog level shifters to the sampling inputs, so that the RadioScope would be able to analyze signals outside of the 0~5V range. As I implemented the project, though, I decided my time would be better spent in rigorous testing of the RadioScope and development of advanced web interfaces (such as the Java oscilloscope interface). The RadioScope would definitely be a much more useful product if I had implemented the various input ranges as planned.

Potential Improvements

As it exists, the RadioScope is already a useful product. But, as with any product, it could be more useful if bigger-faster-better-whatever. In particular, it would be more useful if the input signals could be sampled faster than 62.5 kHz, or with more than 8-bit accuracy. In order to implement either of these improvements, though, the 6811 would probably have to be replaced with a more capable microcontroller.

The on-board ADC (analog-to-digital converter) is already sampling at its maximum rate of 62.5 kHz. For faster sampling, a faster ADC could be connected, but the speed improvement would probably be limited to a factor of 2; at that point, the 6811 would not be able to copy data from one location to another at the rate it emerged from the ADC.

Sampling with more precision would also require a separate ADC; in this case, the problem is that the 6811 has no input/output lines to spare in a straightforward way. (They are mostly used to interface with the 8K NVRAM; a few are used for the status LEDs.) Some sort of programmable interface adapter could be used to provide a bus connection for the offboard ADC, but the speed of operation would be limited, as mentioned above.

Another improvement which the 6811 would be quite capable of is a richer command set. For example, commands could be added which would allow a client to request that the RadioScope capture bursts of samples continuously, sending sample data to the client periodically. Or, the RadioScope could be told to monitor the various input lines and send notifications to the client whenever the inputs met some criteria. These improvements would simply require more functionality in the RadioScope firmware.