Aug 21, 2018 #1 N NewbeeAVR Junior Member level 2 Joined Dec 2, 2017 Messages 21 Helped 0 Reputation 0 Reaction score 0 Trophy points 1 Activity points 195 Hi I bought 16x4 (white on blue) LCD JHD brand from store. But it's contrast is set to high by default. Using potentiometer can not give any variation. What may be the problem?
Hi I bought 16x4 (white on blue) LCD JHD brand from store. But it's contrast is set to high by default. Using potentiometer can not give any variation. What may be the problem?
Aug 21, 2018 #2 D.A.(Tony)Stewart Advanced Member level 7 Joined Sep 26, 2007 Messages 9,004 Helped 1,823 Reputation 3,645 Reaction score 2,197 Trophy points 1,413 Location Richmond Hill, ON, Canada Activity points 59,563 Wrong bias voltage. but the correct voltage depends on LCD, datasheet, your circuit and supply measurements.
Wrong bias voltage. but the correct voltage depends on LCD, datasheet, your circuit and supply measurements.
Aug 22, 2018 #3 N NewbeeAVR Junior Member level 2 Joined Dec 2, 2017 Messages 21 Helped 0 Reputation 0 Reaction score 0 Trophy points 1 Activity points 195 In the following data sheet they have given 5v as the supply voltage. I am using 12v adapter and 7805 to get 5v. **broken link removed**
In the following data sheet they have given 5v as the supply voltage. I am using 12v adapter and 7805 to get 5v. **broken link removed**
Aug 22, 2018 #4 KlausST Advanced Member level 7 Joined Apr 17, 2014 Messages 25,162 Helped 4,868 Reputation 9,757 Reaction score 5,537 Trophy points 1,393 Activity points 168,359 Hi, This is not a complete datasheet.... But it says contrast voltage typ is 4.7V. How did you generate this 4.7V? Did you verify the voltage with a DVM? If not, then do it. Klaus
Hi, This is not a complete datasheet.... But it says contrast voltage typ is 4.7V. How did you generate this 4.7V? Did you verify the voltage with a DVM? If not, then do it. Klaus
Sep 15, 2018 #5 Externet Advanced Member level 2 Joined Jan 29, 2004 Messages 579 Helped 28 Reputation 58 Reaction score 29 Trophy points 1,308 Location Mideast US Activity points 5,670 And observe the contrast adjustment from different angles or points of view.
Sep 15, 2018 #6 P pjmelect Advanced Member level 2 Joined May 13, 2012 Messages 569 Helped 127 Reputation 254 Reaction score 128 Trophy points 1,323 Activity points 5,644 Show your circuit, potentiometer wired wrong?
Sep 21, 2018 #7 D.A.(Tony)Stewart Advanced Member level 7 Joined Sep 26, 2007 Messages 9,004 Helped 1,823 Reputation 3,645 Reaction score 2,197 Trophy points 1,413 Location Richmond Hill, ON, Canada Activity points 59,563 Use pot 10k to 0V = Vss