https://github.com/rsc1975/micropython-hcsr04

Micropython driver for ultrasonic sensor HC-SR04
https://github.com/rsc1975/micropython-hcsr04

Last synced: about 17 hours ago
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Micropython driver for ultrasonic sensor HC-SR04

• Host: GitHub
• URL: https://github.com/rsc1975/micropython-hcsr04
• Owner: rsc1975
• License: apache-2.0
• Created: 2017-01-07T10:43:31.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2023-03-08T19:08:28.000Z (over 1 year ago)
• Last Synced: 2024-08-02T20:44:58.776Z (3 months ago)
• Language: Python
• Size: 15.6 KB
• Stars: 138
• Watchers: 7
• Forks: 70
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-micropython - micropython-hcsr04 - Driver for HC-SR04 ultrasonic distance sensors. (Libraries / Sensors)
• awesome-mpython - micropython-hcsr04 - HC-SR04/05 超声波测距 <img src="https://img.icons8.com/plasticine/30/000000/guarantee.png"> <img src="https://img.icons8.com/cotton/30/000000/add-to-collection--v2.png"> (精选驱动库 / 传感器)

README

        
# HC-SR04 Sensor driver in micropython

Micropython driver for the well-known untrasonic sensor [HC-SR04](https://www.mpja.com/download/hc-sr04_ultrasonic_module_user_guidejohn.pdf)

The driver has been tested on Wemos D1 mini PRO, but It should work on whatever other micropython board, 

if anyone find problems in other boards, please open an issue and we'll see.

## Motivation

The existing drivers in micropython are a bit old and they don't use the relatively new method `machine.time_pulse_us()` which

Is more accurate that whatever other method using pure python, besides the code is compliant with "standard" micropython,

there is no code for specific boards.

Finally I've added a method, `distance_mm()` that don't use floating point operations, for environments where there is no

floating point capabilities.

## Examples of use:

### How to get the distance

The `distance_cm()` method returns a `float` with the distance measured by the sensor.

```python

from hcsr04 import HCSR04

sensor = HCSR04(trigger_pin=16, echo_pin=0)

distance = sensor.distance_cm()

print('Distance:', distance, 'cm')

```

There is another method, `distance_mm()`, that returns the distance in milimeters (`int` type) and **no floating point is used**, designed 

for environments that doesn't support floating point operations.

```python

distance = sensor.distance_mm()

print('Distance:', distance, 'mm')

```

The default timeout is based on the sensor limit (4m), but we can also define a different timeout, 

passing the new value in microseconds to the constructor.

```python

from hcsr04 import HCSR04

sensor = HCSR04(trigger_pin=16, echo_pin=0, echo_timeout_us=1000000)

distance = sensor.distance_cm()

print('Distance:', distance, 'cm')

```

### Error management

When the driver reaches the timeout while is listening the echo pin the error is converted to `OSError('Out of range')`

```python

from hcsr04 import HCSR04

sensor = HCSR04(trigger_pin=16, echo_pin=0, echo_timeout_us=10000)

try:

    distance = sensor.distance_cm()

    print('Distance:', distance, 'cm')

except OSError as ex:

    print('ERROR getting distance:', ex)

```