This is the SparkFun VKey Voltage Keypad, a simple board that adds a keypad to your microcontroller project without using multiple I/O pins. This keypad has 12 pushbutton switches in a 3x4 array. The VKey operates by outputing an analog voltage to encode which key has been pressed, which can be read by an analog to digital converter on a microcontroller on a single input pin.
Traditional digital keypad interfacing techniques can require a large number of digital I/O lines. On a small controller, there may not be many I/O pins left for other tasks. The VKey operates at a voltage of 3.3-5.5V and features a dual opamp which is used as a current source and buffer amplifier.
Note: The SparkFun VKey Voltage Keypad comes with the surface mount components assembled, but the PTH tactile switches are loose, and will need to be soldered to the board. Check the Hookup Guide in the Documents section below for assembly instructions.
This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.
Skill Level: Noob - Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need.
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If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.
Skill Level: Competent - You will be required to reference a datasheet or schematic to know how to use a component. Your knowledge of a datasheet will only require basic features like power requirements, pinouts, or communications type. Also, you may need a power supply that?s greater than 12V or more than 1A worth of current.
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Based on 3 ratings:
1 of 1 found this helpful:
the keypad was very easy to assemble and worked the first time. it would be nice to see a capacitive touch key pad that works with the same voltage output and maybe a little bit smaller package so it could be incorporated into a project. Good job SparkFun.
1 of 2 found this helpful:
I haven’t had the chance to test it yet. I’ll update this as soon as I try it.
Handy pinsaver,almost like using shift registers, but that’s another story. Good build quality, easy to set up. And those screw holes are nice plus. Can’t find any flaws in this.