kopia lustrzana https://github.com/dettus/oledtest
455 wiersze
10 KiB
C
455 wiersze
10 KiB
C
/*
|
|
MIT No Attribution
|
|
|
|
Copyright 2022 Thomas Dettbarn (dettus@dettus.net)
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy of this
|
|
software and associated documentation files (the "Software"), to deal in the Software
|
|
without restriction, including without limitation the rights to use, copy, modify,
|
|
merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
|
|
permit persons to whom the Software is furnished to do so.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
|
|
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
|
|
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
|
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
|
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
|
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <fcntl.h>
|
|
|
|
#define RETVAL_OK 0
|
|
#define RETVAL_NOK -1
|
|
#define GPIO_INPUT 0
|
|
#define GPIO_OUTPUT 1
|
|
|
|
|
|
#define MAXBUFLEN 64
|
|
|
|
#define DELAY_US(us) usleep((us));
|
|
#define DELAY_MS(ms) usleep((ms)*1000);
|
|
|
|
#define SPI_MODE0 0
|
|
#define SPI_MODE1 1
|
|
#define SPI_MODE2 2
|
|
#define SPI_MODE3 3
|
|
|
|
#define SPI_LSBFIRST 0
|
|
#define SPI_MSBFIRST 1
|
|
#define SPI_DELAY //DELAY_US(1)
|
|
|
|
#define BITMAP_HEIGHT 64
|
|
#define BITMAP_WIDTH 128
|
|
|
|
|
|
//// depends on the development board
|
|
|
|
// the way I understand this is, that the physical pins are mapped into
|
|
// the system memory. to accces those, there is some sort of memory
|
|
// offset maybe
|
|
#if 0
|
|
#warning "This mapping is for the Jetson Nano board."
|
|
// Jetson Nano
|
|
// source: https://maker.pro/nvidia-jetson/tutorial/how-to-use-gpio-pins-on-jetson-nano-developer-kit
|
|
const short physicalmapping[41]={
|
|
0, // placeholder. there is no PIN0
|
|
-1, -1,// PIN1 =3.3V DC, PIN2 =5V DC
|
|
-1, -1,
|
|
-1, -1,
|
|
216, -1, //PIN7 = AUDIO_MCLK
|
|
-1, -1,
|
|
50, 79, //PIN11=UART_2_RTS,PIN12=I2S_4_CLK
|
|
14, -1,
|
|
194,232,
|
|
-1, 15,
|
|
16, -1,
|
|
17, 13,
|
|
18, 19,
|
|
-1, 20,
|
|
-1, -1,
|
|
149, -1,
|
|
200,168,
|
|
38, -1,
|
|
76, 51,
|
|
12, 77,
|
|
-1, 78
|
|
};
|
|
#elif 0
|
|
#warning "This mapping is for the Banana Pi board."
|
|
// source: https://wiki.fw-web.de/doku.php?id=en:bpi-r64:gpio
|
|
const short physicalmapping[41]={
|
|
0, // placeholder. there is no PIN0
|
|
-1, -1,// PIN1 =3.3V DC, PIN2 =5V DC
|
|
56, -1,// 3,4
|
|
55, -1,// 5,6
|
|
101, 59, //PIN7 = PWM7,8
|
|
-1, 60,// 9,10
|
|
51, -1, //PIN11=UART_2_RTS,PIN12=I2S_4_CLK
|
|
52, -1, //13,14
|
|
98, 61, //15,16
|
|
-1, 62, //17,18
|
|
68, -1, //19,20
|
|
69, 63, //21,22
|
|
67, 70, //23,24
|
|
-1, 66, //25,26
|
|
58, 57, //27,28
|
|
85, -1, //29,30
|
|
82, 64, //31,32
|
|
-1, -1, //33,34
|
|
-1, 65, //35,36
|
|
86, -1, //37,38
|
|
-1, -1 //39,40
|
|
};
|
|
#else
|
|
#error "Please have a look at the source code and select one of the mappings from the sysfs numbering to the physical pins"
|
|
#endif
|
|
|
|
// this is the GPIO pinout for the waveshare OLED 1.3 SH1106 hat
|
|
#define PIN_CS (physicalmapping[24])
|
|
#define PIN_RST (physicalmapping[22])
|
|
#define PIN_DC (physicalmapping[18])
|
|
#define PIN_BL (physicalmapping[12])
|
|
|
|
#define PIN_SCLK (physicalmapping[23])
|
|
#define PIN_MOSI (physicalmapping[19])
|
|
#define PIN_MISO (physicalmapping[21])
|
|
|
|
|
|
int gpio_export(int pin)
|
|
{
|
|
int fd;
|
|
char buffer[MAXBUFLEN];
|
|
int len;
|
|
fd=open("/sys/class/gpio/export", O_WRONLY);
|
|
if (fd<0)
|
|
{
|
|
fprintf(stderr,"GPIO export for pin %d failed\n",pin);
|
|
return RETVAL_NOK;
|
|
}
|
|
len=snprintf(buffer,MAXBUFLEN,"%d",pin);
|
|
write(fd,buffer,len);
|
|
close(fd);
|
|
return RETVAL_OK;
|
|
}
|
|
|
|
|
|
int gpio_unexport(int pin)
|
|
{
|
|
int fd;
|
|
char buffer[MAXBUFLEN];
|
|
int len;
|
|
fd=open("/sys/class/gpio/unexport", O_WRONLY);
|
|
if (fd<0)
|
|
{
|
|
fprintf(stderr,"GPIO unexport for pin %d failed\n",pin);
|
|
return RETVAL_NOK;
|
|
}
|
|
len=snprintf(buffer,MAXBUFLEN,"%d",pin);
|
|
write(fd,buffer,len);
|
|
close(fd);
|
|
return RETVAL_OK;
|
|
}
|
|
|
|
int gpio_direction(int pin,int direction)
|
|
{
|
|
int fd;
|
|
char buffer[MAXBUFLEN];
|
|
snprintf(buffer,MAXBUFLEN,"/sys/class/gpio/gpio%d/direction",pin);
|
|
fd=open(buffer,O_WRONLY);
|
|
if (fd<0)
|
|
{
|
|
fprintf(stderr,"GPIO direction for pin %d cannot be set\n",pin);
|
|
return RETVAL_NOK;
|
|
}
|
|
if (direction==GPIO_INPUT)
|
|
{
|
|
write(fd,"in",2);
|
|
} else if (direction==GPIO_OUTPUT) {
|
|
write(fd,"out",3);
|
|
} else {
|
|
fprintf(stderr,"Type error for direction for pin %d (%d unknown)\n",pin,direction);
|
|
}
|
|
close(fd);
|
|
|
|
|
|
return RETVAL_OK;
|
|
}
|
|
int gpio_write(int pin,int value)
|
|
{
|
|
int fd;
|
|
char buffer[MAXBUFLEN];
|
|
snprintf(buffer,MAXBUFLEN,"/sys/class/gpio/gpio%d/value",pin);
|
|
fd=open(buffer,O_WRONLY);
|
|
if (fd<0)
|
|
{
|
|
fprintf(stderr,"Cannot access GPIO pin %d\n",pin);
|
|
return RETVAL_NOK;
|
|
}
|
|
write(fd,value?"1":"0",1);
|
|
close(fd);
|
|
return RETVAL_OK;
|
|
}
|
|
|
|
int gpio_read(int pin,int* value)
|
|
{
|
|
int fd;
|
|
char buffer[MAXBUFLEN];
|
|
int len;
|
|
snprintf(buffer,MAXBUFLEN,"/sys/class/gpio/gpio%d/value",pin);
|
|
fd=open(buffer,O_WRONLY);
|
|
if (fd<0)
|
|
{
|
|
fprintf(stderr,"Cannot access GPIO pin %d\n",pin);
|
|
return RETVAL_NOK;
|
|
}
|
|
len=read(fd,buffer,3);
|
|
if (len<0)
|
|
{
|
|
fprintf(stderr,"Unable to read from pin %d\n",pin);
|
|
close(fd);
|
|
return RETVAL_NOK;
|
|
}
|
|
*value=atoi(buffer);
|
|
close(fd);
|
|
return RETVAL_OK;
|
|
}
|
|
|
|
int gpio_pins_up()
|
|
{
|
|
int retval;
|
|
|
|
retval=RETVAL_OK;
|
|
// start with the GPIO configuration
|
|
retval|=gpio_export(PIN_RST);
|
|
retval|=gpio_export(PIN_DC);
|
|
retval|=gpio_export(PIN_BL);
|
|
retval|=gpio_export(PIN_CS);
|
|
|
|
retval|=gpio_direction(PIN_RST, GPIO_OUTPUT);
|
|
retval|=gpio_direction(PIN_DC, GPIO_OUTPUT);
|
|
retval|=gpio_direction(PIN_BL, GPIO_OUTPUT);
|
|
retval|=gpio_direction(PIN_CS, GPIO_OUTPUT);
|
|
|
|
|
|
// continue with the SPI pins
|
|
retval|=gpio_export(PIN_SCLK);
|
|
retval|=gpio_export(PIN_MOSI);
|
|
retval|=gpio_export(PIN_MISO);
|
|
|
|
retval|=gpio_direction(PIN_SCLK, GPIO_OUTPUT);
|
|
retval|=gpio_direction(PIN_MOSI, GPIO_OUTPUT);
|
|
retval|=gpio_direction(PIN_MISO, GPIO_INPUT);
|
|
|
|
return retval;
|
|
}
|
|
|
|
int gpio_pins_down()
|
|
{
|
|
int retval;
|
|
|
|
retval=RETVAL_OK;
|
|
retval|=gpio_write(PIN_RST,0);
|
|
retval|=gpio_write(PIN_DC,0);
|
|
retval|=gpio_write(PIN_BL,0);
|
|
|
|
retval|=gpio_unexport(PIN_RST);
|
|
retval|=gpio_unexport(PIN_DC);
|
|
retval|=gpio_unexport(PIN_BL);
|
|
retval|=gpio_unexport(PIN_CS);
|
|
|
|
retval|=gpio_write(PIN_SCLK,0);
|
|
retval|=gpio_write(PIN_MOSI,0);
|
|
|
|
retval|=gpio_unexport(PIN_SCLK);
|
|
retval|=gpio_unexport(PIN_MOSI);
|
|
retval|=gpio_unexport(PIN_MISO);
|
|
|
|
return retval;
|
|
}
|
|
|
|
void spi_writebyte(unsigned char byte,int mode,int msbfirst)
|
|
{
|
|
int cpol;
|
|
int cpol0;
|
|
int cpha;
|
|
int bits;
|
|
|
|
switch (mode)
|
|
{
|
|
case SPI_MODE0: cpol=0;cpha=0;break;
|
|
case SPI_MODE1: cpol=0;cpha=1;break;
|
|
case SPI_MODE2: cpol=1;cpha=0;break;
|
|
case SPI_MODE3: cpol=1;cpha=1;break;
|
|
}
|
|
cpol0=cpol;
|
|
gpio_write(PIN_SCLK,cpol);
|
|
if (!cpha)
|
|
{
|
|
cpol=1-cpol; // when CPHA=1, the new value is being sampled at the first clock edge
|
|
SPI_DELAY;
|
|
}
|
|
for (bits=0;bits<8;bits++)
|
|
{
|
|
int bit;
|
|
if (msbfirst==SPI_MSBFIRST)
|
|
{
|
|
bit=(byte>>7)&1;
|
|
byte<<=1;
|
|
} else {
|
|
bit=(byte)&1;
|
|
byte>>=1;
|
|
}
|
|
gpio_write(PIN_MOSI,bit); // set the value
|
|
gpio_write(PIN_SCLK,cpol); // 1st clock edge
|
|
cpol=1-cpol;
|
|
SPI_DELAY;
|
|
gpio_write(PIN_SCLK,cpol); // 2nd clock edge
|
|
cpol=1-cpol;
|
|
SPI_DELAY;
|
|
}
|
|
gpio_write(PIN_SCLK,cpol0); // make sure that the SPI clk is the same as before
|
|
}
|
|
void oled_reset()
|
|
{
|
|
gpio_write(PIN_DC,0);
|
|
gpio_write(PIN_RST,1);
|
|
DELAY_MS(200);
|
|
gpio_write(PIN_RST,0);
|
|
DELAY_MS(200);
|
|
gpio_write(PIN_RST,1);
|
|
DELAY_MS(200);
|
|
}
|
|
void oled_init()
|
|
{
|
|
const unsigned char oled_commands[]={
|
|
0xae,0x02,0x10,0x40, 0x81,0xa0,0xc0,0xa6, // turn off oled panel, set low column addr, set high column addr, set start line, set contrast control register, set SEG/Column Mapping, Set COM/ROW scan direction, set normal display
|
|
0xa8,0x3f,0xd3,0x00, 0xd5,0x80,0xd9,0xf1, // set multiplex ration 1:64, 1/64 duty, set display offset, not offset, set display clock, set divide clock as 100frames/sec, set pre-charge period, set pre-chare as 15 clocks & discarge as 1 clock
|
|
0xda,0x12,0xdb,0x40, 0x20,0x02,0xa4,0xa6, // set com pins hardare, ???, set vcomh, set vcom deselect level, set page addr mode, ???, disable entire display on, disable inverse display on,
|
|
0xaf // turn on oled panel
|
|
};
|
|
int i;
|
|
gpio_write(PIN_DC,0);
|
|
for (i=0;i<sizeof(oled_commands);i++)
|
|
{
|
|
spi_writebyte(oled_commands[i],SPI_MODE0,SPI_MSBFIRST);
|
|
}
|
|
}
|
|
void oled_draw(unsigned char* bitmap)
|
|
{
|
|
#define CANVAS_WIDTH 128
|
|
#define CANVAS_PAGES 8
|
|
unsigned char canvas[CANVAS_WIDTH*CANVAS_PAGES];
|
|
int i;
|
|
for (i=0;i<CANVAS_WIDTH*CANVAS_PAGES;i++)
|
|
{
|
|
// each byte in the canvas represents a column of 8 bits from the bitmap
|
|
// 0000
|
|
// 1111
|
|
// 2222
|
|
// 3333
|
|
// 4444
|
|
// ...
|
|
|
|
int j;
|
|
unsigned char byte;
|
|
int x,y;
|
|
byte=0;
|
|
x=i%BITMAP_WIDTH;
|
|
y=(i/BITMAP_WIDTH)*8;
|
|
for (j=0;j<8;j++)
|
|
{
|
|
int bit;
|
|
bit=bitmap[x+(y+j)*BITMAP_WIDTH]?0x80:0x00;
|
|
byte>>=1;
|
|
byte|=bit;
|
|
}
|
|
canvas[i]=byte;
|
|
}
|
|
|
|
for (i=0;i<CANVAS_PAGES;i++)
|
|
{
|
|
int j;
|
|
gpio_write(PIN_DC,0); // write command
|
|
spi_writebyte(0xb0+i,SPI_MODE0,SPI_MSBFIRST); // set page address
|
|
spi_writebyte(0x02,SPI_MODE0,SPI_MSBFIRST); // set low column address
|
|
spi_writebyte(0x10,SPI_MODE0,SPI_MSBFIRST); // set high column address
|
|
gpio_write(PIN_DC,1); // write data
|
|
for (j=0;j<CANVAS_WIDTH;j++)
|
|
{
|
|
spi_writebyte(canvas[i*CANVAS_WIDTH+j],SPI_MODE0,SPI_MSBFIRST);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
int sh1106_up()
|
|
{
|
|
int retval;
|
|
retval=RETVAL_OK;
|
|
retval|=gpio_pins_up();
|
|
// spi mode 0
|
|
// spi master
|
|
// spi clock div 2
|
|
// spi msbfirst
|
|
|
|
// ?? tell the device it should take orders from SPI??
|
|
retval|=gpio_write(PIN_BL,1);
|
|
retval|=gpio_write(PIN_CS,0);
|
|
|
|
if (retval==RETVAL_OK)
|
|
{
|
|
oled_reset();
|
|
oled_init();
|
|
}
|
|
return retval;
|
|
}
|
|
int sh1106_down()
|
|
{
|
|
return gpio_pins_down();
|
|
}
|
|
void graceFulExit(int signal_number)
|
|
{
|
|
printf("shutting down display...\n");
|
|
sh1106_down();
|
|
exit(0);
|
|
}
|
|
int main(int argc,char** argv)
|
|
{
|
|
unsigned char bitmap[BITMAP_WIDTH*BITMAP_HEIGHT]={0};
|
|
unsigned char bitmap2[BITMAP_WIDTH*BITMAP_HEIGHT]={0};
|
|
int i;
|
|
|
|
signal(SIGINT, graceFulExit);
|
|
if (sh1106_up())
|
|
{
|
|
fprintf(stderr,"unable to start up display. sorry");
|
|
return 1;
|
|
}
|
|
for (i=0;i<BITMAP_WIDTH*BITMAP_HEIGHT;i++)
|
|
{
|
|
if ((i%10)<5) bitmap[i]=1;else bitmap[i]=0;
|
|
}
|
|
for (i=0;i<BITMAP_HEIGHT;i++)
|
|
{
|
|
bitmap2[i+i*BITMAP_WIDTH]=1;
|
|
}
|
|
// draw the two bitmaps, one after the other
|
|
for (i=0;i<10;i++)
|
|
{
|
|
oled_draw(bitmap);
|
|
printf("%d\n",i);
|
|
oled_draw(bitmap2);
|
|
}
|
|
printf("press Enter to quit\n");
|
|
fgets(bitmap,sizeof(bitmap),stdin);
|
|
graceFulExit(0);
|
|
|
|
return 0;
|
|
}
|