- Description
Details
Overview
The AD Keypad provides 16 push buttons, and takes up only 1 AD port for controlling. It's suitable for applications where the AD ports are sufficient yet I/O ports are lacking of.
Features
16 push buttons, detection interface
Photos
Parameters and How to
Parameters and Sampling
- AD ideal value: when button pressed, Viv = (button index / 16) x Vref
AD real value: when button pressed, Vrv = (1 ± 6%) x Viv
For instance, suppose Vref = 5, 8th button was pressed, then Viv = (8 / 16) x 5 = 2.5, Vrv = (1 ± 6%) x 2.5, equals to 2.35-2.65 - Abbreviation
- Vref: AD reference voltage
- iv: ideal value
- rv: real value
| ADC Value Detection Range | Measurement Data (Vref=3.3V) | Measurement Data (Vref = 5V) | ||||||
|---|---|---|---|---|---|---|---|---|
| Buttons | 10-bit ADC | 8-bit ADC | Real Value Sampling (V) | Error (V) | Ideal Value (V) | Real Value Sampling (V) | Error (V) | Ideal Value(V) |
| 0 | 0-4 | 0-1 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | (1±6%)x64 | (1±6%)x16 | 0.2054 | -0.00085 | 0.20625 | 0.3112 | -0.0013 | 0.3125 |
| 2 | (1±6%)x128 | (1±6%)x32 | 0.4117 | -0.0008 | 0.4125 | 0.6238 | -0.0012 | 0.625 |
| 3 | (1±6%)x192 | (1±6%)x48 | 0.6233 | 0.00455 | 0.61875 | 0.9444 | 0.0069 | 0.9375 |
| 4 | (1±6%)x256 | (1±6%)x64 | 0.8242 | -0.0008 | 0.825 | 1.2487 | -0.0013 | 1.25 |
| 5 | (1±6%)x320 | (1±6%)x80 | 1.0304 | -0.00085 | 1.03125 | 1.5612 | -0.0013 | 1.5625 |
| 6 | (1±6%)x384 | (1±6%)x96 | 1.2355 | -0.002 | 1.2375 | 1.8719 | -0.0031 | 1.875 |
| 7 | (1±6%)x448 | (1±6%)x112 | 1.4448 | 0.00105 | 1.44375 | 2.189 | 0.0015 | 2.1875 |
| 8 | (1±6%)x512 | (1±6%)x128 | 1.6541 | 0.0041 | 1.65 | 2.5061 | 0.0061 | 2.5 |
| 9 | (1±6%)x576 | (1±6%)x144 | 1.8637 | 0.00745 | 1.85625 | 2.8237 | 0.0112 | 2.8125 |
| 10 | (1±6%)x640 | (1±6%)x160 | 2.0732 | 0.0107 | 2.0625 | 3.1411 | 0.0161 | 3.125 |
| 11 | (1±6%)x704 | (1±6%)x176 | 2.2672 | -0.00155 | 2.26875 | 3.435 | -0.0025 | 3.4375 |
| 12 | (1±6%)x768 | (1±6%)x192 | 2.4712 | -0.0038 | 2.475 | 3.7441 | -0.0059 | 3.75 |
| 13 | (1±6%)x832 | (1±6%)x208 | 2.6789 | -0.00235 | 2.68125 | 4.0588 | -0.0037 | 4.0625 |
| 14 | (1±6%)x896 | (1±6%)x224 | 2.8902 | 0.0027 | 2.8875 | 4.3789 | 0.0039 | 4.375 |
| 15 | (1±6%)x960 | (1±6%)x240 | 3.1092 | 0.01545 | 3.09375 | 4.7107 | 0.0232 | 4.6875 |
How to detect and handle in your code
For 10-bit ADC, the 8th button generates ADC value between (1±6%)x512, the equivalence of "481-543". If the ADC value had been detected to be "510-518" in the code, the 8th button's supposed to have been pressed.
For 8-bit ADC, the 8th button generates ADC value between (1±6%)x128, the equivalence of "120-136". If the ADC value had been detected to be "124-128" in the code, the 8th button's supposed to have been pressed.
Downloads
Development resources: demo codes, schematic, datasheets, etc.
Wiki:
www.waveshare.com/wiki/AD_Keypad
Weight: 0.016 kg
Quick Overview
- AD Keypad × 1
