Lesson 8: LCD Display & Moisture Sensor & Buzzer
Objective
Use Grove - LCD16 * 2 to display the current moisture level. When the moisture level is "wet", Grove - Buzzer will notify you.
Required equipment
Prepare:
- microUSB cable
- Raspberry Pi
- Computer
- Grove Base Hat
- Grove wire
- Grove - LCD display 16*2
- Grove - Moisture sensor
- Grove - Buzzer
Connecting equipment
Step 1 Connect Grove - 16x2 LCD display to I2C port, Grove - Moisture Sensor to A0 port and Grove - Buzzer to PWM port on Grove Base Hat.
Step 2 Connect Base Hat to Raspberry Pi.
Step 3 Use the microUSB to connect Raspberry Pi to your computer.
Programming
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Note Make sure to clone the python.py repository library on your Raspberry Pi. |
Step 1: Enter the following commands to create a Python file
cd grove.py nano lesson_8.py
Step 2：Skopiujthe following code
#!/usr/bin/env python
import time
from mraa import getGpioLookup
from upm import pyupm_buzzer as upmBuzzer
from grove.grove_moisture_sensor import GroveMoistureSensor
from grove.lcd.sh1107g import JHD1802
def main():
# Grove - 16x2 LCD(White on Blue) connected to I2C port
lcd = JHD1802()
# Grove - Moisture Sensor connected to port A0
sensor = GroveMoistureSensor(0)
# Grove - Buzzer connected to PWM port
buzzer = upmBuzzer.Buzzer(getGpioLookup('GPIO12'))
while True:
mois = sensor.moisture
if 0 <= mois and mois < 300:
level = 'dry
elif 300 <= mois and mois < 600:
level = 'moist'
Another:
level = 'wet'
buzzer.playSound(upmBuzzer.BUZZER_DO, 200000)
print('moisture: {}, {}'.format(mois, level))
lcd.setCursor(0, 0)
lcd.write('moisture: {0:>6}'.format(mois))
lcd.setCursor(1, 0)
lcd.write('{0:>16}'.format(level))
time.sleep(1)
if __name__ === '__main__':
main()
Step 3：Uruchomprogram
sudo chmod +x lesson_8.py sudo ./lesson_8.py
If everything goes well, the moisture level will be visible on the LCD. The Buzzer will send out warnings when the moisture level reaches "wet".
pi@raspberrypi:~/grove.py $ sudo ./lesson_8.py moisture: 0, dry moisture: 0, dry moisture: 396, moist moisture: 398, moist moisture: 407, wet moisture: 418, wet ^CTraceback (most recent call last): File "./lesson_8.py", line 41, inmain() File "./lesson_8.py", line 38, in main time.sleep(1) KeyboardInterrupt pi@raspberrypi:~/grove.py $
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