Update README.md

README.md

@@ -21,7 +21,7 @@ sulphur_dioxide (E 220) density
 PM25 density
 
 
-The anlaogue output of the MQ135 is connected to the anlog input of you ESP module. If you are using a nodeMCU or Weemos D1 these have a built in voltage divider on the analogue input which scales 3.3v to 1v, so you need to connect a 180k resistor inline betwen the sensor and the anlogue input pin to allow this to scale From 5v to 1v. If you are connecting directly to a bare ESP8266 chip, then you need to add a voltage divider between the sensor and the analog input to scale form 5v to 1v.
+The anlaogue output of the MQ135 is connected to the anlog input of you ESP module. If you are using a nodeMCU or Weemos D1 these have a built in voltage divider on the analogue input which scales 3.3v to 1v, so you need to connect a 180k resistor ( think I actualy used 140k) inline betwen the sensor and the anlogue input pin to allow this to scale from 5v. If you are connecting directly to a bare ESP8266 chip, then you need to add a voltage divider between the sensor and the analog input to scale form 5v to 1v.
 
 
 The DHT22 temperature sensor is connected to GPIO5