Difference between revisions of "GINPUT"

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GINPUT is a powerful module which provides an easy way to interface different hardware peripherals such as touchscreens to the rest of the library. It provides everything which these peripherals need in order to operate properly such as calibration routines for the touchscreens.
 
GINPUT is a powerful module which provides an easy way to interface different hardware peripherals such as touchscreens to the rest of the library. It provides everything which these peripherals need in order to operate properly such as calibration routines for the touchscreens.
  
== Options ==
+
== API reference ==
The following options are can be set in the [[gfxconf.h]] file:
+
The API reference of the GINPUT module can be found [http://api.ugfx.org/group___g_i_n_p_u_t.html here].
{| class="wikitable"
+
! scope="col"|Option
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! scope="col"|Description
+
|-
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|GINPUT_NEED_MOUSE
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|Enable support for a pointing device such as a [[#touchscreen]].
+
|-
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|GINPUT_NEED_KEYBOARD
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|Not implemented yet.
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|-
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|GINPUT_NEED_TOGGLE
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|Enable support for a digital input.
+
|-
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|GINPUT_NEED_DIAL
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|Enable support for an analog input.
+
|}
+
  
 
== Touchscreen ==
 
== Touchscreen ==
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=== Board file ===
 
=== Board file ===
The [[board file]] API for the GINPUT touchscreen module looks like the following:
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The GINPUT module requires a [[Board File|board file]] for each driver instance. A board file template and corresponding examples can be found under ''/drivers/ginput/touch/xxx/''.
<syntaxhighlight lang=c>
+
static void    init_board(void);
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static bool_t  getpin_pressed(void);
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static void    aquire_bus(void);
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static void    release_bus(void);
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static uint16_t read_value(uint16_t port);
+
</syntaxhighlight>
+
Examples and a template file can be found under ''/drivers/ginput/touch/xxx/''.
+
  
 
=== Calibration ===
 
=== Calibration ===
The GINPUT module provides a calibration routine which uses a three-point algorithm. Three calibration points will show up, one after another. You have to press each. At the end of this process, a 4rd one will appear in the center of the screen. This last one is only used to test if the calibration was successful. If the offset is too big, the calibration process will be restarted automatically.
+
See [[Touchscreen Calibration]].
  
==== Options ====
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== Digital input ==
The following settings can alter the behaviour of the calibration routine:
+
Also known as the ''Toggle'' driver. This driver can be used to interface common digital inputs (GPIOs). Mostly this driver is used to attach hardware buttons to a [[GWIN]] [[Widgets|widget]].
{| class="wikitable"
+
! scope="col"|Option
+
! scope="col"|Description
+
|-
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|GINPUT_MOUSE_CALIBRATE_EXTREMES
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|If this is set to ''TRUE'' in your [[gfxconf.h]], the calibration points are display at the very corner of the display. This gives an overall more accurate result but they are less intuitive.
+
|-
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|GINPUT_MOUSE_MAX_CALIBRATION_ERROR
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|This macro is part of the config file of the driver in your board directory and takes a pixel value. It defines how big the pixel offset of the test point can be before the calibration process is repeated automatically.
+
|}
+
  
==== Storage interface ====
+
== Analog input ==
An unpleasant problem you might run into with your touchscreen device is, that you have to perform a calibration at every reset. To fight this problem, GINPUT provides an interface to easily save and restore calibration data. The interface is very flexible and you can do with the calibration data what ever you want: You can store it on an SD card, in your MCU's internal flash, on an external I²C EEprom or every other possible way to store '''25 bytes'''.
+
Also known as the ''Dial'' driver. This driver can be used to interface slow analog inputs. Mostly this driver is used to attach an analog peripheral such as a potentiometer or a sensor to a [[GWIN]] [[Widgets|widget]].
 +
It can also be used on digital inputs that emulate a graduated ratio output such as a digital "click" wheel (rotary encoder).
  
What you need to do is providing two functions, one to save and one to restore the calibration data:
+
== Keyboard ==
 +
The keyboard driver allows to interface physical keyboards to a µGFX application.
 +
Note that there's also a virtual keyboard widget that provides an on-screen keyboard with customizable layouts. See [[keyboard]].
  
<syntaxhighlight lang=c>
 
void mysave(uint16_t instance, const uint8_t *calbuf, size_t sz);
 
const char *myload(uint16_t instance);
 
</syntaxhighlight>
 
These two function are passed to <code>ginputSetMouseCalibrationRoutines()</code>:
 
<syntaxhighlight lang=c>
 
ginputSetMouseCalibrationRoutines(0, mysave, myload, FALSE);
 
</syntaxhighlight>
 
The first parameter is the instance of the mouse device, the second one the save, the third the restore function. The last parameter defines if the buffer allocated by this function to pass the calibration data needs to be free()'d afterwards or not.
 
  
It's very important that this function gets called before you call the <code>ginputAttachMouse()</code> routine.
 
  
===== Example =====
+
[[Category:Module]]
Here's a simple example which shows how to save and restore the calibration data on an SD-Card using the [[GFILE]] module. Please note that this is just for demonstration. It's highly recommended to check the return value of every function.
+
<syntaxhighlight lang=c>
+
static void mysave(uint16_t instance, const uint8_t *calbuf, size_t size)
+
{
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GFILE* f;
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uint8_t bsize;
+
 
+
(void)instance;
+
 
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bsize = (uint8_t)size;
+
 
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f = gfileOpen("calib.gfx", "w");
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gfileWrite(f, (void*)&bsize, 1);
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gfileWrite(f, (void*)calbuf, bsize);
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gfileClose(f);
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}
+
+
static const char *myload(uint16_t instance)
+
{
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GFILE* f;
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char* buf;
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uint8_t bsize;
+
 
+
(void)instance;
+
 
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f = gfileOpen("calib.gfx", "r");
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+
gfileRead(f, (void*)&bsize, 1);
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buf = gfxAlloc(bsize);
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gfileRead(f, (void*)buf, bsize);
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gfileClose(f);
+
 
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return buf;
+
}
+
</syntaxhighlight>
+
 
+
== Digital input ==
+
ToDo
+
 
+
== Analog input ==
+
ToDo
+

Revision as of 20:16, 16 April 2016

GINPUT architecture

GINPUT is a powerful module which provides an easy way to interface different hardware peripherals such as touchscreens to the rest of the library. It provides everything which these peripherals need in order to operate properly such as calibration routines for the touchscreens.

API reference

The API reference of the GINPUT module can be found here.

Touchscreen

A touchscreen can be interfaced very easily through the GINPUT module. It doesn't matter if it is a resistive, capacitive or any other touchscreen technology.

Board file

The GINPUT module requires a board file for each driver instance. A board file template and corresponding examples can be found under /drivers/ginput/touch/xxx/.

Calibration

See Touchscreen Calibration.

Digital input

Also known as the Toggle driver. This driver can be used to interface common digital inputs (GPIOs). Mostly this driver is used to attach hardware buttons to a GWIN widget.

Analog input

Also known as the Dial driver. This driver can be used to interface slow analog inputs. Mostly this driver is used to attach an analog peripheral such as a potentiometer or a sensor to a GWIN widget. It can also be used on digital inputs that emulate a graduated ratio output such as a digital "click" wheel (rotary encoder).

Keyboard

The keyboard driver allows to interface physical keyboards to a µGFX application. Note that there's also a virtual keyboard widget that provides an on-screen keyboard with customizable layouts. See keyboard.