Update README.md

README.md

@@ -1,7 +1,7 @@
 # simple aht20 driver
 Contains and aht20 driver written in "C"
 
-The AHT20 when coupled with a BMP280 for Bosch are a good replacement for the BME280 that is hard to find or expensive at the time I wrote this driver. It is possible to buy for a good price a breakout board that contains both chips.
+The humidity and temperature sensor AHT20 by Asair, coupled with a BMP280 from Bosch are a good replacement for the BME280 that is hard to find or expensive at the time I wrote this driver. It is possible to buy, for a good price, a breakout board that contains both chips.
 
 The code works for me. Use at your own risk. I do not accept any responsibility related to this code and procedures. It is provided as is with to guarantee or warranty what so ever.
 
@@ -11,7 +11,13 @@ Installation and testing
 
 To compile and run as a test, open the code and define the symbol "testing". This will enable the compilation to the testing code i.e. it defines the "main" procedure.
 
-Make sure that you have installed the pigpio library.
+Prerequisite:
+ -linux on a Raspberry Pi
+ -a correctly connected aht20 device on the default i2c bus.
+ -pigpio library
 
 To compile: gcc aht20.c -lpigpio -o testing
-To test, as root, ./testing
+
+To test, as root: ./testing
+
+The folloing is the relevent datasheet : http://www.aosong.com/userfiles/files/media/Data%20Sheet%20AHT20.pdf