- Mon Dec 26, 2016 1:01 am
#192624
Hi,
I have four Sparkfun HC-SR04R sensors used on a robot controlled with PIC microcontroller at 10 MHz. The minimum distances that I can measure with each of these sensors are : 4 cm (front sensor), 9 cm (rear sensor), 17 cm (left sensor) and 20 cm (right sensor). For example, if an obstacle, like a wall, is 5 cm far from the right sensor, it will measure 20 cm. In this case the ECHO pulse width is around 1 ms (I have no oscilloscope or accurate tool to measure the duration. I used the analog input of an Arduino board). Everything is OK for distances greater than 20 cm.
According to the HC-SR04R datasheet, minimum distance that can be measured with HC-SR04R is 2 cm. Is it an error in the datasheet ?
Thank you for your help.
I have four Sparkfun HC-SR04R sensors used on a robot controlled with PIC microcontroller at 10 MHz. The minimum distances that I can measure with each of these sensors are : 4 cm (front sensor), 9 cm (rear sensor), 17 cm (left sensor) and 20 cm (right sensor). For example, if an obstacle, like a wall, is 5 cm far from the right sensor, it will measure 20 cm. In this case the ECHO pulse width is around 1 ms (I have no oscilloscope or accurate tool to measure the duration. I used the analog input of an Arduino board). Everything is OK for distances greater than 20 cm.
According to the HC-SR04R datasheet, minimum distance that can be measured with HC-SR04R is 2 cm. Is it an error in the datasheet ?
Thank you for your help.