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55 lines
2.3 KiB
Markdown
55 lines
2.3 KiB
Markdown
# pico-htu21d
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This is a MicroPython library for the Raspberry Pi Pico and the
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[HTU21D](https://www.te.com/usa-en/product-CAT-HSC0004.html) Digital Relative Humidity sensor with Temperature output.
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## Example
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```python
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from machine import Pin, I2C
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from utime import sleep
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from htu21d import HTU21D
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i2c0_sda = Pin(8)
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i2c0_scl = Pin(9)
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i2c0 = I2C(0, sda=i2c0_sda, scl=i2c0_scl)
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htu21d = HTU21D(0x40, i2c0)
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while True:
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measurements = htu21d.measurements
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print(f"Temperature: {measurements['t']} °C, humidity: {measurements['h']} %RH")
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sleep(1)
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```
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`measurements` is a dictionary that contains the following values:
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| Field | Description |
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|-------------|------------------------------------------------------------------------------------------------|
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| t | The temperature (°C) |
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| t_dew_point | The temperature at which the water vapor in the air becomes saturated and condensation begins |
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| t_crc_ok | The result of the Cyclic Redundancy Check of the temperature (True, False or None if disabled) |
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| t_adc | The 'raw' temperature value as produced by the sensor |
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| h | The relative humidity (%RH) |
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| h_crc_ok | The result of the Cyclic Redundancy Check of the humidity (True, False or None if disabled) |
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| h_adc | The 'raw' humidity value as produced by the sensor |
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This is the circuit for the example code above. It uses the
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[GY-21 HTU21](https://www.az-delivery.de/en/products/gy-21-temperatur-sensor-modul) breakout board.
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## Customizing configuration
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The default settings use a 12 bits resolution for the relative humidity and a 14 bits resolution for the temperature.
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The heater is disabled and the measurements include the CRC results.
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The next example uses a customized configuration:
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```python
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from htu21d import HTU21D, HTU21DConfiguration
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config = HTU21DConfiguration()
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config.measurement_resolution = HTU21DConfiguration.RH_8_T_12_BIT
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config.heater_enabled = True
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config.crc_enabled = False
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htu21d = HTU21D(0x40, i2c0, config)
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``` |