monic part 2: connecting the keypad
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Next: monic part 3: towards a handheld
This thread shows how to connect a 4x4 matrix keypad and two push buttons. The keypad and push buttons are part of a virtual 6 column, 8 row matrix keypad to be added in the future.
A typical 4x4 matrix keypad has the following pinout:
![[Image: 50028414746_935fedb522_z.jpg]](https://live.staticflickr.com/65535/50028414746_935fedb522_z.jpg)
![[Image: 50028676562_5f599e20c5_z.jpg]](https://live.staticflickr.com/65535/50028676562_5f599e20c5_z.jpg)
Thus 8 pins are required to connect the keypad: 4 pins for the rows and 4 for the columns. Also 4 pins are required for the two push buttons. Since 10 pins are used for the display this gives a total of 22 GPIO pins.
However the EVK has only 16 GPIO pins, so the pins connected to D2-D7 on the display are also connected to the rows of the keypad and the push buttons:
![[Image: 50042024928_34234800d8_z.jpg]](https://live.staticflickr.com/65535/50042024928_34234800d8_z.jpg)
![[Image: 50042560691_59d14d3b0e_z.jpg]](https://live.staticflickr.com/65535/50042560691_59d14d3b0e_z.jpg)
For some reason certain GPIO pins configured as inputs were being pulled low, even with internal pull-up resistors activated. For this reason the following changes (in bold) were made to the connections between the display and EVK:
![[Image: 50035351923_a7c6fca3a6_z.jpg]](https://live.staticflickr.com/65535/50035351923_a7c6fca3a6_z.jpg)
The connections between the keypad/push button input pins and EVK are:
![[Image: 50042803466_4120238ba6_z.jpg]](https://live.staticflickr.com/65535/50042803466_4120238ba6_z.jpg)
The pins are reconfigured in the Config Tools as per the table below:
![[Image: 50042981677_a086eb9946_z.jpg]](https://live.staticflickr.com/65535/50042981677_a086eb9946_z.jpg)
![[Image: 50042166648_c3ca334f44_z.jpg]](https://live.staticflickr.com/65535/50042166648_c3ca334f44_z.jpg)
The header file “display.h” was moved to the “display” folder and the “header” folder in "source" deleted. A new folder “keypad” was created in "source" and a header file “keypad.h” placed in it.
Therefore #include "../header/display.h" at the beginning of "GLCD.c" is changed to #include "display.h".
"keypad.h" is:
Replace the code in "HX8357D.c" with:
Code:
//Port of Adafruit code to i.MX RT1010
/*Copyright (c) 2013 Adafruit Industries. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.*/
//includes
#include <stdint.h>
#include <stdbool.h>
#include "board.h"
#include "pin_mux.h"
#include "clock_config.h"
#include "display.h"
//variables
extern int width;
extern int height;
//functions
void writeRegister32(uint8_t, uint32_t);
void writeRegister8(uint8_t, uint8_t);
void setAddrWindow(int, int, int, int);
void flood(uint16_t, uint32_t);
void setLR(void);
void writeRegisterPair(uint8_t, uint8_t, uint16_t);
void displayPortWrite(unsigned int);
void delayms(unsigned int);
///////////////////////////////////////////////////////////////////////////////
void initDisp(void) {
uint8_t i;
GPIO_PinWrite(BOARD_INITPINS_WR_GPIO, BOARD_INITPINS_WR_PIN, 1U);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(0x00);
for (i = 0; i < 3; i++) displayPortWrite(0x00);
//write to LCD registers
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_SWRESET);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357D_SETC);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0xFF);
displayPortWrite(0x83);
displayPortWrite(0x57);
delayms(250);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_SETRGB);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x00);
displayPortWrite(0x00);
displayPortWrite(0x06);
displayPortWrite(0x06);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357D_SETCOM);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x25); //-1.52V
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_SETOSC);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x68); //Normal mode 70Hz, Idle mode 55 Hz
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_SETPANEL);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x05); //BGR, gate direction swapped
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_SETPWR1);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x00);
displayPortWrite(0x15);
displayPortWrite(0x1C);
displayPortWrite(0x1C);
displayPortWrite(0x83);
displayPortWrite(0xAA);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357D_SETSTBA);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x50);
displayPortWrite(0x50);
displayPortWrite(0x01);
displayPortWrite(0x3C);
displayPortWrite(0x1E);
displayPortWrite(0x08);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357D_SETCYC);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x02);
displayPortWrite(0x40);
displayPortWrite(0x00);
displayPortWrite(0x2A);
displayPortWrite(0x2A);
displayPortWrite(0x0D);
displayPortWrite(0x78);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_COLMOD);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x55);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_MADCTL);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0xC0);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_TEON);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x00);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_TEARLINE);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(0x00);
displayPortWrite(0x02);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_SLPOUT);
delayms(150);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_DISPON);
delayms(50);
}
void setAddrWindow(int x1,int y1, int x2, int y2) {
uint32_t t;
t = x1;
t <<= 16;
t |= x2;
writeRegister32(ILI9341_COLADDRSET, t); // HX8357D uses same registers!
t = y1;
t <<= 16;
t |= y2;
writeRegister32(ILI9341_PAGEADDRSET, t); // HX8357D uses same registers!
}
void writeRegister8(uint8_t a, uint8_t d) {
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(a);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(d);
}
void writeRegister32(uint8_t r, uint32_t d) {
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(r);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");
displayPortWrite(d >> 24);
__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");
displayPortWrite(d >> 16);
__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");
displayPortWrite(d >> 8);
__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");__asm volatile ("nop");
displayPortWrite(d);
}
void flood(uint16_t colour, uint32_t len) {
uint16_t blocks;
uint8_t i, hi = colour >> 8, lo = colour;
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(HX8357_RAMWR);
// Write first pixel normally, decrement counter by 1
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(hi);
displayPortWrite(lo);
len--;
blocks = (uint16_t)(len / 64); //64 pixels/block
if(hi == lo) {
// High and low bytes are identical. Leave prior data
// on the port(s) and just toggle the write strobe.
while(blocks--) {
i = 16; //64 pixels/block/4 pixels/pass
do {
displayPortWrite(lo); displayPortWrite(lo); displayPortWrite(lo); displayPortWrite(lo); //2 bytes/pixel
displayPortWrite(lo); displayPortWrite(lo); displayPortWrite(lo); displayPortWrite(lo); //x 4 pixels
} while(--i);
}
// Fill any remaining pixels (1 to 64)
for(i = (uint8_t)len & 63; i--; ) {
displayPortWrite(lo);
displayPortWrite(lo);
}
} else {
while(blocks--) {
i = 16; // 64 pixels/block / 4 pixels/pass
do {
displayPortWrite(hi); displayPortWrite(lo); displayPortWrite(hi); displayPortWrite(lo);
displayPortWrite(hi); displayPortWrite(lo); displayPortWrite(hi); displayPortWrite(lo);
} while(--i);
}
for(i = (uint8_t)len & 63; i--; ) {
displayPortWrite(hi);
displayPortWrite(lo);
}
}
}
void drawFastVLine(int16_t x, int16_t y, int16_t length, uint16_t colour) {
int16_t y2;
// Initial off-screen clipping
if((length <= 0) || (x<0) || ( x>= width) || (y>= height) || ((y2 = (y+length-1)) < 0)) return;
if(y < 0) { // Clip top
length += y;
y = 0;
}
if(y2 >= height) { // Clip bottom
y2 = height - 1;
length = y2 - y + 1;
}
setAddrWindow(x, y, x, y2);
flood(colour, length);
setLR();
}
void drawFastHLine(int16_t x, int16_t y, int16_t length, uint16_t colour) {
int16_t x2;
// Initial off-screen clipping
if((length <= 0) || (y<0) || (y>= height) || (x>= width) || ((x2 = (x+length-1)) < 0)) return;
if(x < 0) { // Clip left
length += x;
x = 0;
}
if(x2 >= width) { // Clip right
x2 = width - 1;
length = x2 - x + 1;
}
setAddrWindow(x, y, x2, y);
flood(colour, length);
setLR();
}
void setLR(void) {
writeRegisterPair(HX8347G_COLADDREND_HI, HX8347G_COLADDREND_LO, width - 1);
writeRegisterPair(HX8347G_ROWADDREND_HI, HX8347G_ROWADDREND_LO, height - 1);
}
void writeRegisterPair(uint8_t aH, uint8_t aL, uint16_t d) {
uint8_t hi = (d) >> 8, lo = (d);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(aH);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(hi);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(aL);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(lo);
}
void drawPixel(int16_t x, int16_t y, uint16_t colour) {
// Clip
if((x < 0) || (y < 0) || (x >= width) || (y >= height)) return;
setAddrWindow(x, y, width-1, height-1);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 0U); //COMMAND
displayPortWrite(0x2C);
GPIO_PinWrite(BOARD_INITPINS_CD_PERIPHERAL, BOARD_INITPINS_CD_CHANNEL, 1U); //DATA
displayPortWrite(colour >> 8);
displayPortWrite(colour);
}
void setRotation(uint8_t x) {
uint8_t t;
x = (x & 3);
switch (x) {
case 0:
case 2:
width = TFTWIDTH;
height = TFTHEIGHT;
break;
case 1:
case 3:
width = TFTHEIGHT;
height = TFTWIDTH;
break;
}
//HX8357D uses same registers as 9341 but different values
switch (x) {
case 2:
t = HX8357B_MADCTL_RGB;
break;
case 3:
t = HX8357B_MADCTL_MX | HX8357B_MADCTL_MV | HX8357B_MADCTL_RGB;
break;
case 0:
t = HX8357B_MADCTL_MX | HX8357B_MADCTL_MY | HX8357B_MADCTL_RGB;
break;
case 1:
t = HX8357B_MADCTL_MY | HX8357B_MADCTL_MV | HX8357B_MADCTL_RGB;
break;
}
writeRegister8(ILI9341_MADCTL, t); //MADCTL
// For 8357, init default full-screen address window:
setAddrWindow(0, 0, width - 1, height - 1);
}
void displayPortWrite(unsigned int x) {
uint32_t setBitMask;
uint32_t clrBitMask;
setBitMask = ((x & 0x01) << 11) | ((x & 0x02) << (15-1)) | ((x & 0x04) << (16-2)) | ((x & 0x08) << (17-3)) | ((x & 0x10) << (18-4)) | ((x & 0x20) << (20-5)) | ((x & 0x40) << (21-6)) | ((x & 0x80) << (23-7));
clrBitMask = ((~x & 0x01) << 11) | ((~x & 0x02) << (15-1)) | ((~x & 0x04) << (16-2)) | ((~x & 0x08) << (17-3)) | ((~x & 0x10) << (18-4)) | ((~x & 0x20) << (20-5)) | ((~x & 0x40) << (21-6)) | ((~x & 0x80) << (23-7));
GPIO_PortSet(GPIO1, setBitMask);
GPIO_PortClear(GPIO1, clrBitMask);
GPIO_PinWrite(BOARD_INITPINS_WR_GPIO, BOARD_INITPINS_WR_PIN, 0U);
GPIO_PinWrite(BOARD_INITPINS_WR_GPIO, BOARD_INITPINS_WR_PIN, 1U);
}
Replace the code in "monic.c" with:
Code:
//monic 1.0
//includes
#include <stdio.h>
#include "board.h"
#include "peripherals.h"
#include "pin_mux.h"
#include "clock_config.h"
#include "MIMXRT1011.h"
#include "fsl_debug_console.h"
#include <stdbool.h>
#include "display/display.h"
#include "keypad/keypad.h"
//variables
uint16_t keyNumber;
uint16_t keyHeldCtr;
int16_t xCoordinate;
int16_t yCoordinate;
uint16_t fontColour;
int width;
int height;
uint8_t const *fontData;
uint32_t const *fontOffset;
int16_t xCoordinateCursor;
int16_t yCoordinateCursor;
uint8_t size;
extern uint8_t AdafruitClassicData[];
_Bool shift;
//functions
void initDisp(void);
void setRotation(uint8_t);
void fillScreen(uint16_t);
void fillRect(int16_t, int16_t, int16_t, int16_t, uint16_t);
void printString(char*);
void scanKp(void);
_Bool scanColumn(void);
void delay1ms(void);
void delayms(unsigned int);
void delay1us(void);
void delayus(unsigned int);
int main(void) {
#ifdef FIXED_WIDTH_FONT
fontData = AdafruitClassicData;
size = 4;
#else
//fontData = fontVW_1data; //variable-width font data
//fontOffset = fontVW_1Offset;
#endif
BOARD_InitPins();
BOARD_BootClockRUN();
BOARD_InitDebugConsole();
SysTick->CTRL = 0; //disable SysTick
initDisp();
setRotation(3);
fillScreen(BLACK);
fontColour = BLUE;
xCoordinate = 130;
yCoordinate = 0;
printString("monic 1.0");
fontColour = GREEN;
xCoordinate = 0;
yCoordinate = 29;
printString("key pressed:");
fontColour = RED;
size = 3;
xCoordinate = 0;
yCoordinate = 64;
while (1) {
scanKp();
if (xCoordinate > 400) {
xCoordinate = 0;
yCoordinate +=24;
if (yCoordinate > 294) {
yCoordinate = 64;
fillRect(0, 64, 480, 256, BLACK);
}
}
switch (keyNumber) {
case 0:
if (keyHeldCtr == keyHeld) printString("0 H,");
else printString("0,");
break;
case 1:
if (keyHeldCtr == keyHeld) printString("1 H,");
else printString("1,");
break;
case 2:
if (keyHeldCtr == keyHeld) printString("2 H,");
else printString("2,");
break;
case 3:
if (keyHeldCtr == keyHeld) printString("3 H,");
else printString("3,");
break;
case 6:
if (keyHeldCtr == keyHeld) printString("6 H,");
else printString("6,");
break;
case 7:
if (keyHeldCtr == keyHeld) printString("7 H,");
else printString("7,");
break;
case 8:
if (keyHeldCtr == keyHeld) printString("8 H,");
else printString("8,");
break;
case 9:
if (keyHeldCtr == keyHeld) printString("9 H,");
else printString("9,");
break;
case 12:
if (keyHeldCtr == keyHeld) printString("12 H,");
else printString("12,");
break;
case 13:
if (keyHeldCtr == keyHeld) printString("13 H,");
else printString("13,");
break;
case 14:
if (keyHeldCtr == keyHeld) printString("14 H,");
else printString("14,");
break;
case 15:
if (keyHeldCtr == keyHeld) printString("15 H,");
else printString("15,");
break;
case 18:
if (keyHeldCtr == keyHeld) printString("18 H,");
else printString("18,");
break;
case 19:
if (keyHeldCtr == keyHeld) printString("19 H,");
else printString("19,");
break;
case 20:
if (keyHeldCtr == keyHeld) printString("20 H,");
else printString("20,");
break;
case 21:
if (keyHeldCtr == keyHeld) printString("21 H,");
else printString("21,");
break;
case 28:
if (keyHeldCtr == keyHeld) printString("28 H,");
else printString("28,");
break;
case 35:
if (keyHeldCtr == keyHeld) printString("35 H,");
else printString("35,");
break;
default:
if (keyHeldCtr == keyHeld) printString("NF H,");
else printString("NF,");
}
}
}
void delay1us(void) {
SysTick->VAL = 0;
SysTick->CTRL = 5;
while((SysTick->CTRL & 0x00010000) == 0);
SysTick->CTRL = 0;
}
void delayus(unsigned int max) {
unsigned int i;
SysTick->LOAD = 0x000001F4; //reload value for 1us
for (i=0; i<max; i++) delay1us();
}
void delay1ms(void) {
SysTick->VAL = 0;
SysTick->CTRL = 5;
while((SysTick->CTRL & 0x00010000) == 0);
SysTick->CTRL = 0;
}
void delayms(unsigned int max) {
unsigned int i;
SysTick->LOAD = 0x0007A120; //reload value for 1ms
for (i=0; i<max; i++) delay1ms();
}
void scanKp(void) {
GPIO_PinWrite(BOARD_INITPINS_D0_PERIPHERAL, BOARD_INITPINS_D0_CHANNEL, 0U);
GPIO_PinWrite(BOARD_INITPINS_D1_PERIPHERAL, BOARD_INITPINS_D1_CHANNEL, 0U);
GPIO_PinWrite(BOARD_INITPINS_D2_PERIPHERAL, BOARD_INITPINS_D2_CHANNEL, 0U);
GPIO_PinWrite(BOARD_INITPINS_D3_PERIPHERAL, BOARD_INITPINS_D3_CHANNEL, 0U);
GPIO_PinWrite(BOARD_INITPINS_D4_PERIPHERAL, BOARD_INITPINS_D4_CHANNEL, 0U);
GPIO_PinWrite(BOARD_INITPINS_D5_PERIPHERAL, BOARD_INITPINS_D5_CHANNEL, 0U);
GPIO_PinWrite(BOARD_INITPINS_D6_PERIPHERAL, BOARD_INITPINS_D6_CHANNEL, 0U);
GPIO_PinWrite(BOARD_INITPINS_D7_PERIPHERAL, BOARD_INITPINS_D7_CHANNEL, 0U);
delayus(100);
while ((GPIO_PinRead(BOARD_INITPINS_COL0_PERIPHERAL, BOARD_INITPINS_COL0_CHANNEL) == 0) ||
(GPIO_PinRead(BOARD_INITPINS_COL1_PERIPHERAL, BOARD_INITPINS_COL1_CHANNEL) == 0) ||
(GPIO_PinRead(BOARD_INITPINS_COL2_PERIPHERAL, BOARD_INITPINS_COL2_CHANNEL) == 0) ||
(GPIO_PinRead(BOARD_INITPINS_COL3_PERIPHERAL, BOARD_INITPINS_COL3_CHANNEL) == 0) ||
(GPIO_PinRead(BOARD_INITPINS_COL4_PERIPHERAL, BOARD_INITPINS_COL4_CHANNEL) == 0) ||
(GPIO_PinRead(BOARD_INITPINS_COL5_PERIPHERAL, BOARD_INITPINS_COL5_CHANNEL) == 0)) { //wait for key to be released
};
delayms(2); //debounce
while ((GPIO_PinRead(BOARD_INITPINS_COL0_PERIPHERAL, BOARD_INITPINS_COL0_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL1_PERIPHERAL, BOARD_INITPINS_COL1_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL2_PERIPHERAL, BOARD_INITPINS_COL2_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL3_PERIPHERAL, BOARD_INITPINS_COL3_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL4_PERIPHERAL, BOARD_INITPINS_COL4_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL5_PERIPHERAL, BOARD_INITPINS_COL5_CHANNEL))) { //wait for key to be pressed
};
GPIO_PinWrite(BOARD_INITPINS_D0_PERIPHERAL, BOARD_INITPINS_D0_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D1_PERIPHERAL, BOARD_INITPINS_D1_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D2_PERIPHERAL, BOARD_INITPINS_D2_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D3_PERIPHERAL, BOARD_INITPINS_D3_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D4_PERIPHERAL, BOARD_INITPINS_D4_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D5_PERIPHERAL, BOARD_INITPINS_D5_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D6_PERIPHERAL, BOARD_INITPINS_D6_CHANNEL, 1U);
while (1) {
delayms(2); //debounce
keyNumber = 0;
//scan row A - bottom of 4x4 matrix keypad
GPIO_PinWrite(BOARD_INITPINS_D0_PERIPHERAL, BOARD_INITPINS_D0_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D7_PERIPHERAL, BOARD_INITPINS_D7_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
//scan row B
GPIO_PinWrite(BOARD_INITPINS_D7_PERIPHERAL, BOARD_INITPINS_D7_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D6_PERIPHERAL, BOARD_INITPINS_D6_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
//scan row C
GPIO_PinWrite(BOARD_INITPINS_D6_PERIPHERAL, BOARD_INITPINS_D6_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D5_PERIPHERAL, BOARD_INITPINS_D5_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
//scan row D - top row of 4x4 matrix keypad
GPIO_PinWrite(BOARD_INITPINS_D5_PERIPHERAL, BOARD_INITPINS_D5_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D4_PERIPHERAL, BOARD_INITPINS_D4_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
//scan row E
GPIO_PinWrite(BOARD_INITPINS_D4_PERIPHERAL, BOARD_INITPINS_D4_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D3_PERIPHERAL, BOARD_INITPINS_D3_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
//scan row F
GPIO_PinWrite(BOARD_INITPINS_D3_PERIPHERAL, BOARD_INITPINS_D3_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D2_PERIPHERAL, BOARD_INITPINS_D2_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
//scan row G
GPIO_PinWrite(BOARD_INITPINS_D2_PERIPHERAL, BOARD_INITPINS_D2_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D1_PERIPHERAL, BOARD_INITPINS_D1_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
//scan row H
GPIO_PinWrite(BOARD_INITPINS_D1_PERIPHERAL, BOARD_INITPINS_D1_CHANNEL, 1U);
GPIO_PinWrite(BOARD_INITPINS_D0_PERIPHERAL, BOARD_INITPINS_D0_CHANNEL, 0U);
delayus(100);
if (scanColumn()) break;
break; //keyNumber = 48, key not found
}
for (keyHeldCtr = 0; keyHeldCtr < keyHeld; keyHeldCtr++) { //determine if key held
if ((GPIO_PinRead(BOARD_INITPINS_COL0_PERIPHERAL, BOARD_INITPINS_COL0_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL1_PERIPHERAL, BOARD_INITPINS_COL1_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL2_PERIPHERAL, BOARD_INITPINS_COL2_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL3_PERIPHERAL, BOARD_INITPINS_COL3_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL4_PERIPHERAL, BOARD_INITPINS_COL4_CHANNEL)) &&
(GPIO_PinRead(BOARD_INITPINS_COL5_PERIPHERAL, BOARD_INITPINS_COL5_CHANNEL))) break; //exit if key released
delayms(30);
}
}
_Bool scanColumn(void) {
if (GPIO_PinRead(BOARD_INITPINS_COL0_PERIPHERAL, BOARD_INITPINS_COL0_CHANNEL)==0) return true;
keyNumber++;
if (GPIO_PinRead(BOARD_INITPINS_COL1_PERIPHERAL, BOARD_INITPINS_COL1_CHANNEL)==0) return true;
keyNumber++;
if (GPIO_PinRead(BOARD_INITPINS_COL2_PERIPHERAL, BOARD_INITPINS_COL2_CHANNEL)==0) return true;
keyNumber++;
if (GPIO_PinRead(BOARD_INITPINS_COL3_PERIPHERAL, BOARD_INITPINS_COL3_CHANNEL)==0) return true;
keyNumber++;
if (GPIO_PinRead(BOARD_INITPINS_COL4_PERIPHERAL, BOARD_INITPINS_COL4_CHANNEL)==0) return true;
keyNumber++;
if (GPIO_PinRead(BOARD_INITPINS_COL5_PERIPHERAL, BOARD_INITPINS_COL5_CHANNEL)==0) return true;
keyNumber++;
return false;
}
The test code displays the number of the key pressed (followed by "H" if the key was being held down):
![[Image: 50035919691_77c8837ccd_z.jpg]](https://live.staticflickr.com/65535/50035919691_77c8837ccd_z.jpg)
According to the datasheets the rebound time for the keys on the keypad is not more than 2ms and not more than 5ms for the Omron B3F-1052 push buttons. Using a debounce delay of 2ms gives good results - the keys can be pressed quite quickly without misses or bouncing.
The C language combines all the power of assembly language with all the ease-of-use of assembly language
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