Arduino lcd keypad shield program

This pin is used to control the back light of the LCD. Following library will be required to run this sketch. Download the zip file extract the same and copy this to your Arduino library folder.

This library file should be placed at the install folder of Arduino. I have a 64 bit Win7 OS and my arduino library folder address is located at. You may download library file from here. Once the circuit part is done, Arduino is needed to be programmed. Here is the code to get display on LCD.

You may download this code Arduino Sketch from here. After Uploading the code, LCD will display the text as shown in above image. Still you have trouble, then try attaching a power supply of around 7 to 9Vdc to the 2.

I tried in both IDE 1. Here are the screen shots. And thanks for your help! Thank you for such great information, I now have a functional LCD. I am using a shield made by SainSmart. Thank you again. Reply 4 years ago. It could be the LCD shield or to code. I'm not sure if yours works the same as mine. You can check the shield by using a multimeter and check the continuity of the button and then follow the traces to the pins and recheck.

You should only have continuity if the button is pressed. If that checks out it could either be a problem with the Arduino GPIO connectors they ware out over time or could be a problem with the library Pinout. If thats the case you can modify it or define in the sketch. By robmawe91 Follow. More by the author:.

Did you make this project? Share it with us! I Made It! Remote Control Light Switch by alanmerritt in Arduino. Reply Upvote.

Answer Upvote. TaranA3 Question 3 years ago. I downloaded your sketch but when I tried to compile it I got the following error messages: Arduino: 1. For the right button, the analog value is 0 since there is no resistor between it and pin A0.

Therefore, the electric current will just go straight to the ground without running to pin A0. For other buttons, the analog value can be calculated with the voltage divider formula. But after experiencing with this keypad for a while, I found out that the value of the resistor connected to left button and select button of my keypad is not that correct. This could be a technical issue with the manufacturer. With Arduino Uno, only digital pin 2 and 3 are supported with the normal interrupt attachInterrupt.

This leads to another problem which is there is no way of using the normal interrupt on pin A0. With the schematic of the keypad, it is obvious that pin A0 is pulled up.

This means that only signal at Low-level voltage can trigger the Pin Change Interrupt on this pin. You can see more about the voltage level from this page:. But what I encountered with is the voltage that triggers the state change of pin A0 is around 2. I do not have a multimeter for this but with 4 tests, I could narrow down the value from to which is around 2. What you need to do now is just adding a resistor to your pin A0 and connect it to the ground. The value of the resistor is depended on how low you want to set your select button analog value without make pin A0 pull-low.

In my case, after soldering a 3k resistor technically, it is the combination of 3 1kOhm resistors , I can only make the left button work since the analog value of the select button is too high to be considered as a low state and trigger the Pin Change Interrupt. Of course, it is possible to fix this issue by replacing the 5th resistor on the board with a resistor that fits my calculation, or I can just use a potentiometer.

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