PowerArt New 1602 LCD Board Keypad Shield Blue Backlight For Arduino Duemilanove Robot?

Essentially the same 16 col, 2 row, white letters on blue background display shield with 5 buttons, offered by several companies: DFRobot, Sainsmart, etc. -- but at cheapest price, and received from this Chinese dealer in about 2 weeks. Of course, you get what you pay for, and quality from this supplier may be somewhat inferior -- my unit came with an extra piece of PCB on top edge, left over from manufacturing, that needed to be cut off, and another very rough edge that needed sanding down. Functionally it's fine.And, as usual from all suppliers, it came with no documentation. There's a lot online, but some is incorrect and some outdated. The wiki page at DFRobot (search LCD keypad wiki DFR0009) is mostly correct for this board, but a few pins differ. You will want the schematic and to make some careful continuity measurements to be sure.The keypad switches all connect to a voltage divider network, so that each switch press sends a different voltage to pin A0 -- then read by the DFR_Key library or your own code to give whatever action you want. The default values in that .cpp file were not correct for my board; so for the switches to work, I had to look at the actual analogRead values resulting from each switch press, and edit the .cpp file accordingly. For basic display functions (and keypad reading using your own code) you don't need extra libraries, just the basic LiquidCrystal that comes with the Arduino IDE.The shield as it comes, uses up most of your digital pins, leaving only 5 for your own program. But D10 could also be freed up by removing that pin if you don't want software control of your backlight (who needs this anyway?). And remember, the 5 open analog pins can also be configured for digital I/O.

These displays look great, work very well with the Arduino Uno and the delivery was fast. Plug in directly to the board. Couple of changes to interface properly.1. Here are the pin definitions.// select the pins used on the LCD panelLiquidCrystal lcd(8, 9, 4, 5, 6, 7);2. I used these values to make the buttons work properly for the analog input.// For V1.0 comment the other threshold and use the ones below: if (adc_key_in < 50) return btnRIGHT; if (adc_key_in < 195) return btnUP; if (adc_key_in < 380) return btnDOWN; if (adc_key_in < 555) return btnLEFT; if (adc_key_in < 790) return btnSELECT;

I have experienced a very high failure rate with these LCD displays.

worked right out of the package