Difference between revisions of "Keypad"
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==Solutions== | ==Solutions== | ||
| − | There are several solutions to connect a | + | There are several solutions to connect a keypad to your Armadeus board: |
===Keypad directly connected to i.MXL/27=== | ===Keypad directly connected to i.MXL/27=== | ||
====One GPIO for one key==== | ====One GPIO for one key==== | ||
| − | This type of keypad generally called "common ground keypad" is the easiest one to build. If you need more than 6 keys | + | 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. |
<br>Under Test... | <br>Under Test... | ||
| + | |||
====Matrix keypads on i.MX27==== | ====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==== | ====Matrix keypads on i.MXL==== | ||
[[Driver for i.MX GPIO controlled keypads]] | [[Driver for i.MX GPIO controlled keypads]] | ||
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{add a big picture of the keypad link with APF_DEV_LIGHT} | {add a big picture of the keypad link with APF_DEV_LIGHT} | ||
{add a big picture of the keypad link with APF_DEV_FULL} | {add a big picture of the keypad link with APF_DEV_FULL} | ||
| − | | [[Image:keypad.svg|thumb|3x4 matrix keypad connected to i. | + | | [[Image:keypad.svg|thumb|3x4 matrix keypad connected to i.MX GPIOs|150px]] |
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Revision as of 22:20, 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
- use target/demos/keypad_test/ test tool
- If you have a graphical LCD connected to your board (= virtual terminal), then you should see what you type.
- If you don't have any virtual terminal, but only the serial console:
# cat /sys/class/input/input0/event0/dev 13:64
If corresponding device node in /dev/input/ is not existing, then:
# mkdir -p /dev/input # mknod /dev/input/event0 c 13 64
# cat /dev/input/event0
Then you should see weirds characters when pressing keyboard keys:
�,~~_�,}�}�3T,QToT6,TT�,�;��, � �
Links
external links (for exemple: locomo driver model)
