SeeedStudio ultrasonic sensor vs. Parallax PING)))

[eschulma]

I have used the PING))) ultrasonic sensors in the past, but found them a bit pricey at $30/each, and other vendors seem to have similar price points. Today however I found one by SeeedStudio that is only $15:

http://www.seeedstudio.com/wiki/index.php?title=Ultra_Sonic_range_measurement_module

Half-price is pretty compelling of course. It looks identical to the PING, the code to control it is exactly the same, and the only difference I could find (in the admittedly sparse wiki) were minor differences in effective range, and that SeeedStudio recommends allowing 50 ms between measurements while PING))) states that the next measurement can be made after only 0.2 ms. Though in the PING))) manual -- and my own experience -- failure to detect an object means the return pulse lasts 18.5ms so I don't know if that 0.2 ms number makes any sense.

Would welcome any comments on this. I may end up buying 3 of these for my next robot, so it's a noticeable expense.

Erica

[eschulma]

Well after a little digging I've found that this is very similar to the HC-SR04 -- SeeedStudio clearly cut and pasted from their manual:

http://letsmakerobots.com/node/30209?s=l

and the HC-SR04 only costs $8/ea or less (from China it's $3 if you can wait) so now we are down a factor of 4-10 in price. However, the HC-SR04 requires two data pins while the others do it with one. It's still only one input pin so I could always use a shift register with the Arduino to handle the extra output pin, but that's a bit of a hassle.

Anyway, if anyone has used either of these, please let me know.

[omkar]

http://www.ebay.com.au/itm/270755218294?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Thats what i used to do this trial before putting it on my bot...
Range finder trial HC SR04 Arduino.MTS