1号機で作成したMariaDBの情報を介して、2号機のTFTDisplayに温度、湿度、気圧、照度の情報を表示させる【2号機の設定】。

■2号機の設定
１．まずは接続できるかを確認。

source ~/vpy/bin/activate

mysql -h 192.168.1.XX -P 3306 -u miyamo -p
use miyamodb
select * from room_env
で内容表示されるので、環境的にはＯＫ。

２．pythonを　room_env_disp2.py　で保存作成。

import digitalio
import board
import RPi.GPIO as GPIO
from PIL import Image, ImageDraw, ImageFont

from adafruit_rgb_display import st7735
import mysql.connector

# First define some constants to allow easy resizing of shapes.
BORDER = 20
FONTSIZE = 24

# Configuration for CS and DC pins (these are PiTFT defaults):
cs_pin = digitalio.DigitalInOut(board.CE0)
dc_pin = digitalio.DigitalInOut(board.D25)
reset_pin = digitalio.DigitalInOut(board.D24)

# Config for display baudrate (default max is 24mhz):
BAUDRATE = 24000000

# Create Display
disp = st7735.ST7735R(
    board.SPI(),
    rotation=270,
    cs=cs_pin,
    dc=dc_pin,
    rst=reset_pin,
    baudrate=BAUDRATE,
)

# Create blank image for drawing.
# Make sure to create image with mode 'RGB' for full color.
width = 160
height = 128
image = Image.new("RGB", (width, height))

# Get drawing object to draw on image.
draw = ImageDraw.Draw(image)

# Draw a green filled box as the background
draw.rectangle((0, 0, width, height), fill=(0,0,0))
disp.image(image)

# Load a TTF Font
font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", FONTSIZE)

# db connect
def main():     
# mysql connect 
    cnt = mysql.connector.connect(
    host='miyamodb',
    port='3306',
    db='miyamodb',
    user='miyamo',
    password='miyamoXXXX',
    charset='utf8'
    )

    db = cnt.cursor(buffered=True)   

#room_env select
    sql = 'select temperature, humidity, air_pressure, illuminance from room_env where id = 1'

    db.execute(sql)

    for (temperature, humidity, air_pressure, illuminance) in db:
        print(f"{temperature} {humidity} {air_pressure} {illuminance}")

# Draw Some temp
    text = f"{temperature}"
    print(text)
    (font_width, font_height) = font.getsize(text)
    draw.text(
        (0, 1),
        text,
        font=font,
        fill=(176, 224, 230),
        )

# Display image.
    disp.image(image)

#Draw Some humi
    text = f"{humidity}"
    print(text)
    (font_width, font_height) = font.getsize(text)
    draw.text(
        (0, 32),
        text,
        font=font,
        fill=(154, 205, 50),
        )

# Display image.
    disp.image(image)

# Draw Some air_p
    text = f"{air_pressure}"
    print(text)
    (font_width, font_height) = font.getsize(text)
    draw.text(
        (0, 64),
        text,
        font=font,
        fill=(176, 224, 230),
        )

# Display image.
    disp.image(image)

# Draw Some illum
    text = f"{illuminance}"
    print(text)
    (font_width, font_height) = font.getsize(text)
    draw.text(
        (0,100),
        text,
        font=font,
        fill=(154, 205, 50),
        )

# Display image.
    disp.image(image)

# db.close
    db.close()
# cnt.close
    cnt.close()

if __name__ == "__main__":
    main()

３．仮想環境で実行

source ~/vpy/bin/activate

room_env_disp2.py　実行で　以下で表示された。　

４．cronに登録 5分毎に実行。　

sudo crontab -e

*/5 * * * * cd /home/pi/ && /home/pi/vpy/bin/python room_env_disp2.py >> /tmp/cron.log 2>&1