Speed Example - any ideas?
John Kauffman
Posts: 653
I'm looking for a way to easily and clearly demonstrate to students the SX's speed (using SX/B) compared to BS2.
When I brought this up a few months ago, Bean mentioned controlling a video. I agree that is, intellectually, proof. And I mention the video module to students. But I'd like to give them·something that they can build in a half hour on each platform and then see the BS2 obviously fail to do the job while the SX hums away like a darling.
For example, I once saw a simple demo of a transistor vs a relay for·switching LEDs. A frequency was generated and sent to both. They started out at 1 Hz and both did fine. As the frequency increased the transistors continued fine while the relays started rattling all over the place and missing cycles. The smoke coming out of a relay was the kicker.
I guess I am trying to find something that is simple, but changes so fast that an SX can catch several cycles while the BS2 misses it.
Criteria:
The projects have to be built with a few simple components, like a WAM kit and an SX Tech Tool
Easy to explain what is happening at a WAM-ish level of experience
Built in a half hour
SX code must be written in SX/B
The only idea I have so far is to link the two platforms, simultaneouly start them counting loops and then simultaniously stop the looping. Compare the number of loops done by each.
Any ideas are appreciated. Thanks.
When I brought this up a few months ago, Bean mentioned controlling a video. I agree that is, intellectually, proof. And I mention the video module to students. But I'd like to give them·something that they can build in a half hour on each platform and then see the BS2 obviously fail to do the job while the SX hums away like a darling.
For example, I once saw a simple demo of a transistor vs a relay for·switching LEDs. A frequency was generated and sent to both. They started out at 1 Hz and both did fine. As the frequency increased the transistors continued fine while the relays started rattling all over the place and missing cycles. The smoke coming out of a relay was the kicker.
I guess I am trying to find something that is simple, but changes so fast that an SX can catch several cycles while the BS2 misses it.
Criteria:
The projects have to be built with a few simple components, like a WAM kit and an SX Tech Tool
Easy to explain what is happening at a WAM-ish level of experience
Built in a half hour
SX code must be written in SX/B
The only idea I have so far is to link the two platforms, simultaneouly start them counting loops and then simultaniously stop the looping. Compare the number of loops done by each.
Any ideas are appreciated. Thanks.
Comments
Perhaps you can write similar programs on the BS-2 and SX to generate stepped sine waves through the use of lookup tables. Insert adjustable pauses into each each program to alter the output frequency. Have the students adjust the length of the pauses either via pushbuttons or serial input. You may want to compare the waveforms on an oscilloscope.
For low frequencies (those with long pauses between table lookups and output value changes), the waveforms should be roughly similar. As the frequency increases (while the corresponding pause between updates decreases) it should become increasingly evident that the BS-2 is spending much more time "between pauses" than the SX. When the pause is reduced to zero, both devices will have reached their maximum cycle speed for the program. This should be evidence by the SX displaying a much higher frequency and over all a larger frequency range.
Now, if you really want to nail the point home, create another program that uses interrupts on the SX to allow it to send serial data in the foreground (a BS-2 taunting message perhaps) while the above waveform generation process happens smoothly in the background. Let's see a BS-2 do that!
Whatever you create, be sure to share it with us. We all like to show off what our SX's can do from time to time! [noparse];)[/noparse]
- Sparks
Another is a race. Use a decade counter w/ some led's to see who can count faster.
I'll cook up two. The race would be a first go and then the wave on a 'scope will be for the ones that have mastered that tool.