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A smaller ultrasonic sensor like HC-SR04 running on 3V or less??

Former Member

We are working on a IoT, where my need is to have a small device (~20mm diameter) having a Arduino (RFDuino, etc) with a ultrasonic sensor running on 3V or less. The issue we are facing is that the HC-SR04 is too wide and runs at 5V. So we are looking into getting some other sensor for this job (note: the distance range for our application is small: 0cm to 50cm or max 100cm).

 

Thanks

  • 0 in reply to Robert Peter Oakes

    The range on this might be a little more than the OP has aked for.

    Ulrasonics need to have a period between the 'ping' and the bounced echo as the transducer is still ringing and therefore giving a false indication.

    It's usually specified what the minimum distance is.(18cm in this case)

     

    Advanced Mode

    This is the factory default mode. In this mode it is possible for the SRF01 to measure range all the way down to zero. Initially, the minimum range the SRF01 can detect is around 18cm or 7 inches. For the SRF01 to be able to measure all the way down to 0cm, it acquires a precision crystal lock on the transducer's characteristics. This happens after 5 rangings have been completed with 30cm or more of free space in front of the sensor. When this happens the "lock" bit is set (bit 0 in the status byte) and the SRF01 can measure from 0 to 600cm (0-6meters). 

    During operation the SRF01 maintains the transducer lock automatically, provided it gets an occasional (every few minutes) set of 5 consecutive rangings of greater than 30cm. The "lock" state of the SRF01 can be checked in by reading the "Lock" bit, which is bit 0 in the status register. A high (or logic 1) indicates transducer lock has been achieved and the SRF01 will work down to 0cm. Where the SRF01 is not able to maintain its lock, it will release it (lock bit = zero) and re-acquire it as soon as possible.

     

    For the very close you might want to switch to IR.

     

     

    Mark