Adafruit Si7021 User Manual Download Page 12

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This sensor also has a serial number which you might find handy! Call

sensor.readSerialNumber()

to read out the 8 bytes

of unique ID. Then you can access them from

sensor.sernum_a

and

sensor.sernum_b

https://learn.adafruit.com/adafruit-si7021-temperature-plus-humidity-sensor

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Summary of Contents for Si7021

Page 1: ...Adafruit Si7021 Temperature Humidity Sensor Created by lady ada Last updated on 2018 11 21 06 58 57 PM UTC...

Page 2: ...t_Si7021 library Load Demo Library Reference Python CircuitPython CircuitPython Microcontroller Wiring Python Computer Wiring CircuitPython Installation of Si7021 Library Python Installation of Si7021...

Page 3: ...perature Humidity Sensor the best way to prove the weatherman wrong This lovely sensor for Silicon labs has 3 relative humidity measurements with a range of 0 80 RH and 0 4 C temperature accuracy at a...

Page 4: ...3V or 5V power logic There s a PTFE filter to keep the sensor clean that s the white flat thing on top Also comes with some pin header Some light soldering is required to attach the header but it s e...

Page 5: ...or on board that will take 3 5VDC and safely convert it down To power the board give it the same power as the logic level of your microcontroller e g for a 5V micro like Arduino use 5V 3v3 this is the...

Page 6: ...soldering procedure is identical Prepare the header strip Cut the strip to length if necessary It will be easier to solder if you insert it into a breadboard long pins down Adafruit Industries https...

Page 7: ...akout board Place the breakout board over the pins so that the short pins poke through the breakout pads Adafruit Industries https learn adafruit com adafruit si7021 temperature plus humidity sensor P...

Page 8: ...ps on soldering be sure to check out our Guide to Excellent Soldering https adafru it aTk You re done Check your solder joints visually and continue onto the next steps Adafruit Industries https learn...

Page 9: ...ro digital 3 Connect the SDA pin to the I2C data SDA pin on your Arduino On an UNO 328 based Arduino this is also known as A4 on a Mega it is also known as digital 20 and on a Leonardo Micro digital 2...

Page 10: ...uit all about arduino libraries install use https adafru it aYM Load Demo Open up File Examples Adafruit_Si7021 si7021 and upload to your Arduino wired up to the sensor Thats it Now open up the serial...

Page 11: ...it was not found Once initialized you can query the temperature in C with Which will return floating point decimal fractional temperature You can convert to Fahrenheit by multiplying by 1 8 and adding...

Page 12: ...find handy Call sensor readSerialNumber to read out the 8 bytes of unique ID Then you can access them from sensor sernum_a and sensor sernum_b Adafruit Industries https learn adafruit com adafruit si...

Page 13: ...an use we will show wiring for Raspberry Pi For other platforms please visit the guide for CircuitPython on Linux to see whether your platform is supported https adafru it BSN Here s the Raspberry Pi...

Page 14: ...inux guide to get your computer ready https adafru it BSN Once that s done from your command line run the following command sudo pip3 install adafruit circuitpython si7021 If your default Python is ve...

Page 15: ...7021 Create library object using our Bus I2C port i2c busio I2C board SCL board SDA sensor adafruit_si7021 SI7021 i2c while True print nTemperature 0 1f C sensor temperature print Humidity 0 1f sensor...

Page 16: ...Python Library Docs Python Library Docs https adafru it C3f Adafruit Industries https learn adafruit com adafruit si7021 temperature plus humidity sensor Page 16 of 19...

Page 17: ...y on GitHub https adafru it rAw EagleCAD PCB files on GitHub https adafru it rAB Si7021 A20 datasheet https adafru it rAC K R Smith calibration notes https adafru it BfU Schematic Fabrication Print Ad...

Page 18: ...Adafruit Industries https learn adafruit com adafruit si7021 temperature plus humidity sensor Page 18 of 19...