47 lines
2.1 KiB
Markdown
47 lines
2.1 KiB
Markdown
SGP30
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=========
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Library to read eCO2 and TVOC from the [SGP30 sensor](https://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/9_Gas_Sensors/Sensirion_Gas_Sensors_SGP30_Datasheet_EN.pdf). Based on the _smbus2_ i2c library for ease of use.
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It should be compatible with both Python 2 and 3
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Quick usage-example:
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--------------------
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from smbus2 import SMBusWrapper
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from sgp30 import SGP30
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import time
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with SMBusWrapper(1) as bus:
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sgp = SGP30(bus, baseline_filename=BASELINE_FILENAME+".TESTING")
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print("resetting all i2c devices")
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sgp.i2c_general_call()
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print(sgp.read_features())
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print(sgp.read_serial())
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sgp.init_sgp()
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for i in range(300):
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print(sgp.read_measurements())
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time.sleep(0.1)
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sgp.store_baseline()
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bus.close()
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Current design considerations:
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------------------------------
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The class strives to to be light-weight and portable. It is currently a bit to tightly bound to the smbus2 class. In most cases I try to ease of readability rather than purity or speed.
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Features that are known to be missing (listing in rough order of importance):
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-----------------------------------------------------------------------------
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* The handing of baseline values is not that great, it should probably be up to the end user to save and restore them as needed.
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* Write doc-strings for all or at least most methods.
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* reading raw-values.
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* A more "driver like" class that takes care of all chip identification, polling at regular intervals, restoring baseline and so on.
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* Run real hardware tests under Python3
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Hardware notices:
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-----------------
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If you have the Adafruit board with built in level shifters and voltage regulator it is should work if you just plug in [SDA to pin 3, SCL to pin 5, VCC to pin 17 and GND to pin 20](https://pinout.xyz/pinout/i2c). You should then be able to find the SGP30 an address 0x58 using `i2cdetect -y 1`. If you get an error message you probably need to enable i2c in the kernel using [raspi-config and reboot](https://learn.sparkfun.com/tutorials/raspberry-pi-spi-and-i2c-tutorial>)
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Feel free to contact me with bugs, questions or issues.
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