When I measure the resistance of a circuit with the PicoBoard, how can I convert Scratch's 0 to 100 value to ohms?

thanks!

mike_b wrote:

When I measure the resistance of a circuit with the PicoBoard, how can I convert Scratch's 0 to 100 value to ohms?

thanks!

The Picoboard ‘measures’ a value between 0 and 100 through a pull-up resistor of 10K. I don't think you can make a good measurement of resistance.
Otherwise the best way is trial-and-error. Just try different resistors and see what values you get.

Good luck and please post your results in this thread.

I don't have a PicoBoard but if it is simply a pullup via 10k, and the unknown resistor is 10k then I think it will read 50. 20k -> 67. 5k -> 33. If this is how it works, and those test readings agree then I think the formula is R = V * 10k / (100 - V) where R is the unknown resistor, V is the measured value 0 to 100. It's likely to give good accuracy around 10k but less accurate beyond 100 times bigger or smaller. Still quite useful.

You can just check out my project, I made one that is maybe a good example. It requires a pico board to play, or do anything. I don't have enough money for the actual board, but I made the script. Check it out and hopefully it helps!