This routine will be useful where you need to take readings from any sensor and use the previous reading as a comparison for an action to be taken. Nothing special about this.<\/p>\n\n\n\n
I use an LDR connected in a voltage divider configuration to pin A0.<\/p>\n\n\n\n
\/*\nThis application will read the light level from the LDR\non power-up and will use that initial value as the first reference\nfor the min\/max light levels.\nIt will then continually compare that initial stored value\nwith the next reading and update the min\/max levels accordingly\n*\/\n\nint ldr=A0;\nint tempmin,tempmax;\nint initreading;\n\nvoid setup()\n{\nSerial.begin(9600);\npinMode(ldr,INPUT);\ndelay(200);\ninitreading=analogRead(ldr); \/\/ take an initial reading\ntempmin=initreading; \/\/ assign the initial reading to the min\ntempmax=initreading; \/\/ and the max readings\nSerial.print("Initial light level: ");\nSerial.println(initreading);\nSerial.println("This is lux(min) and lux(max)");\n}\n\nvoid loop()\n{\nint reading=analogRead(ldr);\ndelay(1000);\n\nif (reading<tempmin)\n{\ntempmin=reading;\n\nSerial.print("New minimum of: ");\nSerial.print(reading);\nSerial.println(" read from the sensor");\n}\nif (reading>tempmax)\n{\ntempmax=reading;\nSerial.print("New maximum of: ");\nSerial.print(reading);\nSerial.println(" read from the sensor");\n}\nelse\n{\nSerial.print("Current mimimum is: ");\nSerial.print(tempmin);\nSerial.print(" and the maximum is: ");\nSerial.print(tempmax);\nSerial.print(" with a current lux of: ");\nSerial.println(reading);\n}\n}<\/code><\/pre>\n\n\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"
This routine will be useful where you need to take readings from any sensor and use the previous reading as a comparison for an action to be taken. Nothing special about this. I use an LDR connected in a voltage … Continue reading