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# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/iio/proximity/devantech-srf04.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Devantech SRF04 ultrasonic range finder
maintainers:
- Andreas Klinger <ak@it-klinger.de>
description: |
Bit-banging driver using two GPIOs:
- trigger-gpio is raised by the driver to start sending out an ultrasonic
burst
- echo-gpio is held high by the sensor after sending ultrasonic burst
until it is received once again
Specifications about the driver can be found at:
http://www.robot-electronics.co.uk/htm/srf04tech.htm
properties:
compatible:
items:
- const: devantech,srf04
trig-gpios:
description:
Definition of the GPIO for the triggering (output) This GPIO is set
for about 10 us by the driver to tell the device it should initiate
the measurement cycle.
maxItems: 1
echo-gpios:
description:
Definition of the GPIO for the echo (input)
This GPIO is set by the device as soon as an ultrasonic burst is sent
out and reset when the first echo is received.
Thus this GPIO is set while the ultrasonic waves are doing one round
trip.
It needs to be an GPIO which is able to deliver an interrupt because
the time between two interrupts is measured in the driver.
See Documentation/devicetree/bindings/gpio/gpio.txt for information
on how to specify a consumer gpio.
maxItems: 1
required:
- compatible
- trig-gpios
- echo-gpios
examples:
- |
#include <dt-bindings/gpio/gpio.h>
proximity {
compatible = "devantech,srf04";
trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
echo-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>;
};
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