Member #142854

Member Since: July 18, 2010

Country: United States

  • The datasheet you linked is actually a very out-of-date preliminary data brief. Also, you can see in the official datasheet that the range value is stored in RESULT__RANGE_VAL, an unsigned 8-bit register with units of mm. An unsigned 8-bit register cannot store values exceeding 25.5cm, and I think your claim of "up to 50cm" is very misleading.

  • Warning to everyone about to buy this: the product description makes false claims about the ranging ability of the sensor. Sparkfun is claiming that this sensor "Measures absolute range up to 50cm", however this is not physically possible under ANY conditions.

    To obtain a range measurement you must read the value stored in the RESULT__RANGE_VAL register. This is an unsigned 8-bit register that has units of mm. Since this is an 8-bit register, the maximum possible value is 255 mm. In other words, it is impossible to read a value higher than 25.5cm from this sensor.

    An old preliminary data brief (that is now out-of-date) claimed up to 50cm for proximity ranging, however, ST has since switched to storing the range value in an 8-bit register which can no longer store values higher than 25.5cm.