Difference between revisions of "Keypad"
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==Test== | ==Test== | ||
| − | + | ===Quick try=== | |
| − | * If you have a graphical LCD connected to your board (= virtual terminal), then you should see what you type. | + | * If you have a graphical LCD connected to your board (= virtual terminal), then you should see what you type (if your keypad keys are mapped to alphanumeric keyboard keys). |
| − | * If you don't have any virtual terminal, but only the serial console: | + | * If you don't have any virtual terminal, but only the serial console (''event0'' may be ''event1'' if you already have a running touchscreen): |
| + | <pre class="apf"> | ||
| + | # cat /dev/input/event0 | ||
| + | </pre> | ||
| + | Then you should see weirds characters when pressing keyboard keys: | ||
| + | <pre class="apf"> | ||
| + | �,~~_�,}�}�3T,QToT6,TT�,�;��, � � | ||
| + | </pre> | ||
| + | * If corresponding device node in ''/dev/input/'' is not existing, then: | ||
| + | <pre class="apf"> | ||
# cat /sys/class/input/input0/event0/dev | # cat /sys/class/input/input0/event0/dev | ||
13:64 | 13:64 | ||
| − | |||
# mkdir -p /dev/input | # mkdir -p /dev/input | ||
# mknod /dev/input/event0 c 13 64 | # mknod /dev/input/event0 c 13 64 | ||
| + | </pre> | ||
| − | + | ===Deeper one === | |
| − | + | * use ''target/demos/keypad_test/'' test tool | |
| − | + | ||
| − | + | ||
| − | + | ||
| − | === | + | |
| − | external links (for exemple: locomo driver model) | + | ==Links== |
| + | * external links (for exemple: locomo driver model) | ||
[[Category:UserInput]] | [[Category:UserInput]] | ||
Revision as of 23:33, 4 December 2009
How to connect a keypad to your Armadeus board
Contents
Introduction
Your Armadeus board allows you to connect a (matrix or not) keypad as input device. Keypads are a collection of switches assembled together to emulate a kind of keyboard to ease user interaction with your system.
Solutions
There are several solutions to connect a keypad to your Armadeus board:
Keypad directly connected to i.MXL/27
One GPIO for one key
This type of keypad generally called "common ground keypad" is the easiest one to build: connect your switch to an i.MX GPIO (with a pullup) on one side and to the ground on the other side . If you need more than 6 keys, this construction is however "GPIO consuming" and you would better use matrix keypads.
Under Test...
Matrix keypads on i.MX27
The i.MX27 has an internal controller that can drive 8x8 keypads (= 64 keys with 16 dedicated pins): Keypad usage on i.MX27. Please consult the i.MX27 Reference Manual (Chapter 25) for more informations.
Matrix keypads on i.MXL
Driver for i.MX GPIO controlled keypads
| By default your board supports a direct connection with a 4x4 matrix keypad using the CSI lines: CSI_MCLK, CSI_D0...CSI_D6.
The driver uses the i.MXL GPIO's internal pull-up, therefore your board does not need any additional external resistor.
{add a big picture of the keypad link with APF_DEV_LIGHT} {add a big picture of the keypad link with APF_DEV_FULL} |
FPGA solution
Development are also ongoing to connect matrix keypads using the FPGA...
Test
Quick try
- If you have a graphical LCD connected to your board (= virtual terminal), then you should see what you type (if your keypad keys are mapped to alphanumeric keyboard keys).
- If you don't have any virtual terminal, but only the serial console (event0 may be event1 if you already have a running touchscreen):
# cat /dev/input/event0
Then you should see weirds characters when pressing keyboard keys:
�,~~_�,}�}�3T,QToT6,TT�,�;��, � �
- If corresponding device node in /dev/input/ is not existing, then:
# cat /sys/class/input/input0/event0/dev 13:64 # mkdir -p /dev/input # mknod /dev/input/event0 c 13 64
Deeper one
- use target/demos/keypad_test/ test tool
Links
- external links (for exemple: locomo driver model)
