Hi John,
There should be a number of threads on the forum about driving the SRF004/005s, but I've not used one myself. I do recall that there is a "trick" to make the PICaxe switch quickly from Transmit (a pulse) to Receive (PULSIN) on a single pin. I wouldn't expect the ultrasonics to be particularly affected by "loud" sounds, but I do recall that the early Remote Controlled TV sets used ultrasonics and could be "upset" by things like jangling keys on a keyring.
There is a current thread in the Active forum about the TOF10120 Laser Rangefinder (which appears to be the other "easy to use" device) and the Dronebots Workshop gives a useful comparative review of Ultrasonics versus Laser Time Of Flight.
The problem with Laser TOF is that the time delay is extremely short (nanoseconds), so it appears that these sensors use various "tricks", but the manufacturer won't give details even in their official data sheet. So unless size is a particular issue, personally, I would put my money on Ultrasonics (or there are also some rather interesting low cost "Radar" devices).
Generally it's best to describe your actual application in detail in an Active Forum post. But if you want to keep the details "secret", then give as much information as possible concerning the requirements for Range, Accuracy, Speed, Cost and the nature of any particular "Interfering" signals (i.e. Noise, Light Levels, Electrical Interference, etc.).
Cheers, Alan.
There should be a number of threads on the forum about driving the SRF004/005s, but I've not used one myself. I do recall that there is a "trick" to make the PICaxe switch quickly from Transmit (a pulse) to Receive (PULSIN) on a single pin. I wouldn't expect the ultrasonics to be particularly affected by "loud" sounds, but I do recall that the early Remote Controlled TV sets used ultrasonics and could be "upset" by things like jangling keys on a keyring.
There is a current thread in the Active forum about the TOF10120 Laser Rangefinder (which appears to be the other "easy to use" device) and the Dronebots Workshop gives a useful comparative review of Ultrasonics versus Laser Time Of Flight.
The problem with Laser TOF is that the time delay is extremely short (nanoseconds), so it appears that these sensors use various "tricks", but the manufacturer won't give details even in their official data sheet. So unless size is a particular issue, personally, I would put my money on Ultrasonics (or there are also some rather interesting low cost "Radar" devices).
Generally it's best to describe your actual application in detail in an Active Forum post. But if you want to keep the details "secret", then give as much information as possible concerning the requirements for Range, Accuracy, Speed, Cost and the nature of any particular "Interfering" signals (i.e. Noise, Light Levels, Electrical Interference, etc.).
Cheers, Alan.