[General] Arduino float reading

[Rohit Choudhary]

I want to make array of 20 buttons.such that i sud be able to know which button was pressed at what time!
intially i was usiing digital pins of arduino,but it is giving me float value with no proper reading.what sud i do??

 

[notionSunday]

I want to make array of 20 buttons.such that i sud be able to know which button was pressed at what time!
intially i was usiing digital pins of arduino,but it is giving me float value with no proper reading.what sud i do??

You'll have to use pull-up or down resistors to solve the floating problem. Maybe you already know that.

For so many buttons(more than I/0 pins), if you don't want to use shift registers, maybe the analog pin could be used w/ resistors set up as voltage dividers and say 4 buttons
for each analog input. Each of the 4 buttons, when pressed, would give a unique value.

 

[DNA Robotics]

I agree with the analog method. I got this 16 X 2 LCD Keypad Shield for Arduino V2. It does a nice job with 5 buttons on one analog input (A0). Any combination of the 5 buttons lead to 32 different key values.

https://linksprite.com/wiki/index.php5?title=16_X_2_LCD_Keypad_Shield_for_Arduino_V2