/*
* max7219.c
*
* MAX7219 8x8 도트매트릭스 체인 구동 + 좌->우 텍스트 스크롤.
*
* 배선(하드웨어 SPI1 사용):
* MAX7219 DIN -> PA7 (SPI1_MOSI)
* MAX7219 CLK -> PA5 (SPI1_SCK)
* MAX7219 CS -> PA4 (일반 GPIO, 소프트웨어 제어)
* MAX7219 VCC -> 5V, GND -> GND
*
* 레지스터 모델: MAX7219는 디코드모드 OFF 상태에서 DIGIT0~7 레지스터 각각이
* 매트릭스의 "행(row)"이며, 그 8bit가 그 행의 8개 열(column)을 나타낸다.
* 따라서 프레임을 만들 때는 (행, 각 모듈별 8bit) 형태로 SPI에 실어야 한다.
*/
#include "main.h"
#include "max7219.h"
#include <string.h>
#include <ctype.h>
#define MAX7219_REG_NOOP 0x00
#define MAX7219_REG_DIGIT0 0x01
#define MAX7219_REG_DECODEMODE 0x09
#define MAX7219_REG_INTENSITY 0x0A
#define MAX7219_REG_SCANLIMIT 0x0B
#define MAX7219_REG_SHUTDOWN 0x0C
#define MAX7219_REG_DISPLAYTEST 0x0F
#define MAX7219_TOTAL_COLS (MAX7219_NUM_DEVICES * 8)
/* 표시 가능한 최대 문자열 길이(글자당 6컬럼 = 5폭+1간격) + 앞뒤 여백 */
#define MAX7219_TEXT_MAX_CHARS 64
#define MAX7219_COLBUF_SIZE (MAX7219_TOTAL_COLS * 2 + MAX7219_TEXT_MAX_CHARS * 6)
static SPI_HandleTypeDef *s_hspi;
static uint8_t s_colbuf[MAX7219_COLBUF_SIZE];
static uint32_t s_colbuf_len;
static uint32_t s_scroll_offset;
/* ---- 5x7 폰트: 행(row) 단위 원본 표현. 각 바이트의 bit4..bit0 = 좌->우 5개 컬럼 ---- */
typedef struct { char ch; uint8_t rows[7]; } Glyph5x7;
static const Glyph5x7 s_font[] = {
{' ', {0b00000,0b00000,0b00000,0b00000,0b00000,0b00000,0b00000}},
{'0', {0b01110,0b10001,0b10011,0b10101,0b11001,0b10001,0b01110}},
{'1', {0b00100,0b01100,0b00100,0b00100,0b00100,0b00100,0b01110}},
{'2', {0b01110,0b10001,0b00001,0b00010,0b00100,0b01000,0b11111}},
{'3', {0b11111,0b00010,0b00100,0b00010,0b00001,0b10001,0b01110}},
{'4', {0b00010,0b00110,0b01010,0b10010,0b11111,0b00010,0b00010}},
{'5', {0b11111,0b10000,0b11110,0b00001,0b00001,0b10001,0b01110}},
{'6', {0b00110,0b01000,0b10000,0b11110,0b10001,0b10001,0b01110}},
{'7', {0b11111,0b00001,0b00010,0b00100,0b01000,0b01000,0b01000}},
{'8', {0b01110,0b10001,0b10001,0b01110,0b10001,0b10001,0b01110}},
{'9', {0b01110,0b10001,0b10001,0b01111,0b00001,0b00010,0b01100}},
{'A', {0b01110,0b10001,0b10001,0b11111,0b10001,0b10001,0b10001}},
{'B', {0b11110,0b10001,0b10001,0b11110,0b10001,0b10001,0b11110}},
{'C', {0b01111,0b10000,0b10000,0b10000,0b10000,0b10000,0b01111}},
{'D', {0b11110,0b10001,0b10001,0b10001,0b10001,0b10001,0b11110}},
{'E', {0b11111,0b10000,0b10000,0b11110,0b10000,0b10000,0b11111}},
{'F', {0b11111,0b10000,0b10000,0b11110,0b10000,0b10000,0b10000}},
{'G', {0b01111,0b10000,0b10000,0b10011,0b10001,0b10001,0b01111}},
{'H', {0b10001,0b10001,0b10001,0b11111,0b10001,0b10001,0b10001}},
{'I', {0b01110,0b00100,0b00100,0b00100,0b00100,0b00100,0b01110}},
{'J', {0b00111,0b00010,0b00010,0b00010,0b00010,0b10010,0b01100}},
{'K', {0b10001,0b10010,0b10100,0b11000,0b10100,0b10010,0b10001}},
{'L', {0b10000,0b10000,0b10000,0b10000,0b10000,0b10000,0b11111}},
{'M', {0b10001,0b11011,0b10101,0b10101,0b10001,0b10001,0b10001}},
{'N', {0b10001,0b11001,0b10101,0b10101,0b10011,0b10001,0b10001}},
{'O', {0b01110,0b10001,0b10001,0b10001,0b10001,0b10001,0b01110}},
{'P', {0b11110,0b10001,0b10001,0b11110,0b10000,0b10000,0b10000}},
{'Q', {0b01110,0b10001,0b10001,0b10001,0b10101,0b10010,0b01101}},
{'R', {0b11110,0b10001,0b10001,0b11110,0b10100,0b10010,0b10001}},
{'S', {0b01111,0b10000,0b10000,0b01110,0b00001,0b00001,0b11110}},
{'T', {0b11111,0b00100,0b00100,0b00100,0b00100,0b00100,0b00100}},
{'U', {0b10001,0b10001,0b10001,0b10001,0b10001,0b10001,0b01110}},
{'V', {0b10001,0b10001,0b10001,0b10001,0b10001,0b01010,0b00100}},
{'W', {0b10001,0b10001,0b10001,0b10101,0b10101,0b10101,0b01010}},
{'X', {0b10001,0b10001,0b01010,0b00100,0b01010,0b10001,0b10001}},
{'Y', {0b10001,0b10001,0b01010,0b00100,0b00100,0b00100,0b00100}},
{'Z', {0b11111,0b00001,0b00010,0b00100,0b01000,0b10000,0b11111}},
{'.', {0b00000,0b00000,0b00000,0b00000,0b00000,0b01100,0b01100}},
{'!', {0b00100,0b00100,0b00100,0b00100,0b00100,0b00000,0b00100}},
{'-', {0b00000,0b00000,0b00000,0b11111,0b00000,0b00000,0b00000}},
};
#define FONT_COUNT (sizeof(s_font) / sizeof(s_font[0]))
static const Glyph5x7 *font_lookup(char c)
{
if (c >= 'a' && c <= 'z') c = (char)(c - 'a' + 'A'); /* 소문자 -> 대문자 */
for (uint32_t i = 0; i < FONT_COUNT; i++)
{
if (s_font[i].ch == c) return &s_font[i];
}
return &s_font[0]; /* 지원 안 하는 문자는 공백으로 */
}
/* row(0=top..6=bottom) 문자열 비트에서 col(0=left..4)에 해당하는 컬럼 바이트를 뽑아
* bit r 위치에 채운다 (bit0=top row ... bit6=bottom row). */
static uint8_t glyph_col_byte(const Glyph5x7 *g, uint8_t col)
{
uint8_t val = 0;
for (uint8_t r = 0; r < 7; r++)
{
uint8_t bit = (g->rows[r] >> (4 - col)) & 0x01U;
val |= (uint8_t)(bit << r);
}
return val;
}
/* ---- 저수준 SPI 전송 ---- */
static inline void cs_low(void) { HAL_GPIO_WritePin(MAX7219_CS_PORT, MAX7219_CS_PIN, GPIO_PIN_RESET); }
static inline void cs_high(void) { HAL_GPIO_WritePin(MAX7219_CS_PORT, MAX7219_CS_PIN, GPIO_PIN_SET); }
/* 체인의 모든 모듈에 동일한 (reg,data)를 전송 (초기화/공통 설정용) */
static void max7219_write_all(uint8_t reg, uint8_t data)
{
uint8_t buf[2] = { reg, data };
cs_low();
for (uint32_t i = 0; i < MAX7219_NUM_DEVICES; i++)
{
HAL_SPI_Transmit(s_hspi, buf, 2, HAL_MAX_DELAY);
}
cs_high();
}
/* 한 행(row 0~7)에 대해 모듈별 8bit 데이터를 체인에 맞는 순서로 전송.
* dev_data[0] = MCU와 가장 가까운(첫번째) 모듈. SPI 시프트 특성상 체인에서는
* 가장 먼 모듈 데이터부터 먼저 밀어넣어야 CS 상승 시 올바르게 래치된다. */
static void max7219_send_row(uint8_t row, const uint8_t *dev_data)
{
uint8_t reg = (uint8_t)(MAX7219_REG_DIGIT0 + row);
cs_low();
#if MAX7219_REVERSE_CHAIN
for (int32_t dev = 0; dev < MAX7219_NUM_DEVICES; dev++)
#else
for (int32_t dev = MAX7219_NUM_DEVICES - 1; dev >= 0; dev--)
#endif
{
uint8_t buf[2] = { reg, dev_data[dev] };
HAL_SPI_Transmit(s_hspi, buf, 2, HAL_MAX_DELAY);
}
cs_high();
}
void MAX7219_Init(SPI_HandleTypeDef *hspi)
{
s_hspi = hspi;
max7219_write_all(MAX7219_REG_DISPLAYTEST, 0x00);
max7219_write_all(MAX7219_REG_SCANLIMIT, 0x07); /* 8자리(행) 전부 사용 */
max7219_write_all(MAX7219_REG_DECODEMODE, 0x00); /* BCD 디코드 없음: 매트릭스 모드 */
max7219_write_all(MAX7219_REG_INTENSITY, 0x04); /* 밝기 0x0~0xF */
max7219_write_all(MAX7219_REG_SHUTDOWN, 0x01); /* 0=shutdown, 1=normal operation */
MAX7219_Clear();
}
void MAX7219_SetIntensity(uint8_t level)
{
max7219_write_all(MAX7219_REG_INTENSITY, (uint8_t)(level & 0x0FU));
}
void MAX7219_Clear(void)
{
uint8_t zeros[MAX7219_NUM_DEVICES];
memset(zeros, 0, sizeof(zeros));
for (uint8_t row = 0; row < 8; row++)
{
max7219_send_row(row, zeros);
}
}
void MAX7219_SetText(const char *text)
{
uint32_t len = 0;
/* 화면 밖에서 스크롤 들어오도록 앞쪽 여백(패널 폭만큼 공백) */
for (uint32_t i = 0; i < MAX7219_TOTAL_COLS && len < MAX7219_COLBUF_SIZE; i++)
{
s_colbuf[len++] = 0x00;
}
for (const char *p = text; *p != '\0' && len + 6 <= MAX7219_COLBUF_SIZE; p++)
{
const Glyph5x7 *g = font_lookup(*p);
for (uint8_t c = 0; c < 5; c++)
{
s_colbuf[len++] = glyph_col_byte(g, c);
}
s_colbuf[len++] = 0x00; /* 글자 사이 1컬럼 간격 */
}
/* 화면 밖으로 완전히 빠져나가도록 뒤쪽 여백 */
for (uint32_t i = 0; i < MAX7219_TOTAL_COLS && len < MAX7219_COLBUF_SIZE; i++)
{
s_colbuf[len++] = 0x00;
}
s_colbuf_len = len;
s_scroll_offset = 0;
}
static void render_frame(void)
{
uint8_t dev_row[MAX7219_NUM_DEVICES];
if (s_colbuf_len == 0) return;
for (uint8_t row = 0; row < 8; row++)
{
for (uint32_t dev = 0; dev < MAX7219_NUM_DEVICES; dev++)
{
uint8_t val = 0;
for (uint8_t c = 0; c < 8; c++)
{
uint32_t col_index = (s_scroll_offset + dev * 8U + c) % s_colbuf_len;
uint8_t bit = (s_colbuf[col_index] >> row) & 0x01U;
#if MAX7219_MIRROR_COLS
val |= (uint8_t)(bit << c);
#else
val |= (uint8_t)(bit << (7 - c));
#endif
}
dev_row[dev] = val;
}
max7219_send_row(row, dev_row);
}
}
uint8_t MAX7219_ScrollStep(void)
{
render_frame();
if (s_colbuf_len == 0) return 1;
s_scroll_offset++;
if (s_scroll_offset >= s_colbuf_len)
{
s_scroll_offset = 0;
return 1;
}
return 0;
}
/* 각 모듈에 스크롤 없이 고정 숫자를 동시에 정적으로 표시(디버그용).
* dev=0 -> "1", dev=1 -> "2" ... 모듈이 서로 다른 내용을 "동시에" 보여주는지,
* 그리고 계속 켜진 상태로 유지되는지(깜빡임/순차갱신 없는지) 확인하는 용도. */
void MAX7219_ShowDeviceIndexTest(void)
{
uint8_t dev_row[MAX7219_NUM_DEVICES];
const Glyph5x7 *glyphs[MAX7219_NUM_DEVICES];
for (uint32_t dev = 0; dev < MAX7219_NUM_DEVICES; dev++)
{
char digit = (char)('1' + (dev % 9));
glyphs[dev] = font_lookup(digit);
}
for (uint8_t row = 0; row < 8; row++)
{
for (uint32_t dev = 0; dev < MAX7219_NUM_DEVICES; dev++)
{
uint8_t val = 0;
if (row < 7) /* 글꼴은 7행(0~6)까지만 있음, 8번째 행은 항상 빈 줄 */
{
for (uint8_t c = 0; c < 5; c++) /* 글꼴 폭 5, 나머지 3컬럼은 여백(0) */
{
uint8_t bit = (glyphs[dev]->rows[row] >> (4 - c)) & 0x01U;
#if MAX7219_MIRROR_COLS
val |= (uint8_t)(bit << (2 + c));
#else
val |= (uint8_t)(bit << (7 - c));
#endif
}
}
dev_row[dev] = val;
}
max7219_send_row(row, dev_row);
}
} |
