TCS230 color sensor

It looks like the datasheet for the device is here:

http://www.dfrobot.com/image/data/SEN010­1/TCS3200%20TCS3210.pdf

The interface isn't great for Espruino, but it seems like it should be easy enough to make it work:

• Set OE = 1 (off)
  
• Set S0 = 0, S1 = 1 (for the low range frequency out)
  
• S2,S3 specify the colour to check
  
• setWatch on the output pin, and use the timestamp to work out the frequency
  
• digitalPulse(OE,0,1) (lower OE for 1 millisecond - don't do it for long or there will be so many oscillations that Espruino won't be able to process them all)