I have been thinking about getting one or two of the ubiquitous SRF04 sonar sensors, as they are so cheap, I have one Maxbotics EZ0 and it rocks, adaptive beam, self calibration, and all the output types and most importantly, it never misses anything, even at an angle it still detects stuff pretty relyably but, $30 is a lot for one sensor.. on the other hand, there is the SRF04, just a plain jane sonar with no features, but only $2-$7 big price difference, but, I have heard some nasty things about their detection abilities, and they are also about double the size.
Thoughts? Experences? anything at all you have to say would be awesome :)
My experience is that they actually work pretty well for the price. The one major catch I have found is that they require a FULL 5v to operate. Not 4.5v or 4.8v, but a full 5v. This is not a problem if your bot uses say, a 7v supply and a 5v regulator but if your bot is using a (4) AA pack (@ 4.8’ish volts with rechargebles) the sensor will not work. Other than that, yes, the numbers fluctuate a bit and it will “miss” from time to time, but at $4, still a pretty good deal.
sounds like I am going to have to buy a cupple, altho I am still a little worried about detection issues, the world is a messy place and, the ez0 is really good at filtering noise and detecting even small objects. I have no experiance with the SRF04 so I cant speak to that.
The only reason to prefer the HC-SR04s is either you like the Wall-E look or you’re not into paying $30 when a $2 version is staring you in the face. The Maxbotix are better in terms of size, useability, and flexibility. As they should be, considering the significant price difference. I believe what really separates the two are the different ways you can retrieve the distance readings from the Maxbotix. It helps when you’re trying to use slower uCs that aren’t fast enough to pick up the pulses from the 'SR04. Also Maxbotix sensors are nifty in the way you can chain them together for sequencial or parallel operation.
editor’s note - For the record I’ve used both the 'SR04 and the EZ4, which is a narrow-beam version of the EZ0.