Ultrasonic sensors $1.95 (edit)

ajward

An eBay "buy it now" with free shipping. Didn't seem like too bad a deal if you need 10 of 'em.

http://www.ebay.com/itm/10PCS-New-Arduino-Ultrasonic-Module-HC-SR04-Distance-Measuring-Transducer-Sensor-/251011566398?pt=LH_DefaultDomain_0&hash=item3a71748b3e#ht_2726wt_1165

Edit: Arrr... wouldn't you know... a 10 fer $21.49 just popped up.
http://www.ebay.com/itm/10x-HC-SR04-Ultrasonic-Sensor-Distance-Measuring-Module-/270752285926?pt=LH_DefaultDomain_0&hash=item3f0a1804e6#ht_3245wt_1141

erco

Undercutting my daily deals, huh? I'll get you and your little dog, too!

http://forums.parallax.com/showthread.php?135899-Four-Buck-Ultrasonic-Sensor&p=1112912&viewfull=1#post1112912

ajward

That's where I have you Dr. erco. Your'e unaware that my faithful assistant has been shadowing you at every turn!



Bwaahahahaha... =D

erco

I've won a few Ebay bids for even less, including this one for the newer SRF-05 module, supposedly better detection characteristics than the SRF-04 modules. http://www.ebay.com/itm/271032717401

But none the Ebay cheapies I've received (even the 05 units) have the one pin mode (more PING like) as mentioned at http://www.robot-electronics.co.uk/htm/srf05tech.htm

ajward

Down to $19.50 for a 10 piece lot. Perhaps these folks studied business tactics under Milo Minderbinder! ;-)

erco

Rotate your $1.95 ultrasonic sensor with your $2.76 stepper motor & board, and you'll really have something!

http://www.ebay.com/itm/5V-Stepper-Motor-28BYJ-48-With-Drive-Test-Module-Board-ULN2003-5-Line-4-Phase-/170781372685?pt=LH_DefaultDomain_0&hash=item27c35cf10d