The PING4 peripheral connect to up to four Parallax Ping))) ultrasonic distance sensors. The PING4 peripheral uses the GPIO4 card.
The quad Parallax Ping))) peripherals uses the four bidirectional I/O pins on a GPIO4 card to control up to four Parallax Ping))) sensors. Typically you would use the pin header version of the GPIO4 card and would connect +5 Volts and ground to the auxiliary power connector.
Resources for the in4 peripheral include a read-only data register and a read-write configuration register to determine which pins are monitored for changes.
distance :sensor ID and Distance.
Distance is a read-only resource that works with dpcat. The stream of data is line oriented and each line of output has a digit that indicates the sensor number followed by the distance given in units of one-tenth of an inch. A distance of zero indicates that the sensor is not connected or is not responding. Typical output from the distance resource might appear as:
0 1055 1 55 2 0 3 1848 0 1094
enable : enable or disable individual sensors. The enable resource takes a single hexadecimal character terminated by a newline. The LSB of the enable register corresponds to the lowest numbered sensor, sensor ID 0. A set bit enables the sensor and a cleared bit disables it. At start-up all sensors are disabled.
NOTE: Only enable active sensors. The output can stop if a sensor is not present or stops responding.
Enable the first two sensors and start monitoring the reported distances.
dpset ping4 enable 3 dpcat ping4 distance