errors occurring in a sketch that was previously running fine

All I did was add the readings from an LM393 sensor and was displaying the results on a 20x4 LCD. I've been working on the sketch through various iterations. Hope you can point me in the right direction.

Arduino: 1.6.5 (Windows 8.1), Board: "Arduino/Genuino Uno"

Build options changed, rebuilding all

Using library DHT sensor library in folder: C:\Users\Danny\Documents\Arduino\libraries\DHT_sensor_library

Using library Wire in folder: C:\Program Files (x86)\Arduino\libraries\Wire-master

Using library LiquidCrystal I2C in folder: C:\Program Files (x86)\Arduino\libraries\LiquidCrystal_I2C-1.1.2

Using library HTI2CLCD in folder: C:\Program Files (x86)\Arduino\libraries\HTI2CLCD (legacy)

C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++ -c -g -Os -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10605 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR -IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino -IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\standard -IC:\Users\Danny\Documents\Arduino\libraries\DHT_sensor_library -IC:\Program Files (x86)\Arduino\libraries\Wire-master -IC:\Program Files (x86)\Arduino\libraries\LiquidCrystal_I2C-1.1.2 -IC:\Program Files (x86)\Arduino\libraries\HTI2CLCD C:\Users\Danny\AppData\Local\Temp\build1068218786188628700.tmp\Greenhouse.cpp -o C:\Users\Danny\AppData\Local\Temp\build1068218786188628700.tmp\Greenhouse.cpp.o

Greenhouse.ino:7:9: error: 'DHTPIN' was not declared in this scope Greenhouse.ino:21:9: error: expected constructor, destructor, or type conversion before '(' token 'DHTPIN' was not declared in this scope

It is hard to help when you have not posted your program.

Also post the working version so we can see exactly what changes you made.

...R

LM393 is not a sensor, it's a comparator, and the output is open collector.