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The MAX7219/MAX7221 are compact, serial input/output common-cathode display drivers that interface microprocessors (μPs) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs. Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8x8 static RAM that stores each digit. Only one external resistor is required to set the segment current for all LEDs. The MAX7221 is compatible with SPI™, QSPI™, and MICROWIRE™, and has slewrate-limited segment drivers to reduce EMI. A convenient 4-wire serial interface connects to all common μPs. Individual digits may be addressed and updated without rewriting the entire display. The MAX7219/MAX7221 also allow the user to select code-B decoding or no-decode for each digit. The devices include a 150μA low-power shutdown mode, analog and digital brightness control, a scanlimit register that allows the user to display from 1 to 8 digits, and a test mode that forces all LEDs on.
LibDriver MAX7219 is the full function driver of MAX7219 launched by LibDriver.It provides digital tube display, dot matrix display, cascade display and other functions. LibDriver is MISRA compliant.
/src includes LibDriver MAX7219 source files.
/interface includes LibDriver MAX7219 SPI platform independent template.
/test includes LibDriver MAX7219 driver test code and this code can test the chip necessary function simply.
/example includes LibDriver MAX7219 sample code.
/doc includes LibDriver MAX7219 offline document.
/datasheet includes MAX7219 datasheet.
/project includes the common Linux and MCU development board sample code. All projects use the shell script to debug the driver and the detail instruction can be found in each project's README.md.
/misra includes the LibDriver MISRA code scanning results.
Reference /interface SPI platform independent template and finish your platform SPI driver.
Add the /src directory, the interface driver for your platform, and your own drivers to your project, if you want to use the default example drivers, add the /example directory to your project.
You can refer to the examples in the /example directory to complete your own driver. If you want to use the default programming examples, here's how to use them.
#include "driver_max7219_basic.h"
uint8_t i;
uint8_t res;
const max7219_no_decode_font_t display[] = {MAX7219_NO_DECODE_FONT_0, MAX7219_NO_DECODE_FONT_1,
MAX7219_NO_DECODE_FONT_2, MAX7219_NO_DECODE_FONT_3,
MAX7219_NO_DECODE_FONT_4, MAX7219_NO_DECODE_FONT_5,
MAX7219_NO_DECODE_FONT_6, MAX7219_NO_DECODE_FONT_7,
MAX7219_NO_DECODE_FONT_8, MAX7219_NO_DECODE_FONT_9 };
res = max7219_basic_init();
if (res != 0)
{
max7219_interface_debug_print("max7219: basic init failed.\n");
return 1;
};
...
for (i = 0; i < 8; i++)
{
uint8_t s;
s = 1;
res = max7219_basic_set_display((max7219_digital_t)(i + 1), display[s]);
if (res != 0)
{
max7219_interface_debug_print("max7219: set display failed.\n");
return 1;
}
...
}
...
(void)max7219_basic_deinit();
return 0#include "driver_max7219_cascade.h"
uint8_t res;
uint16_t i, j;
res = max7219_cascade_init();
if (res != 0)
{
max7219_interface_debug_print("max7219: cascade init failed.\n");
return 1;
}
...
for (j = 0; j < 8; j++)
{
for (i = 0; i < MATRIX_CASCADE_LENGTH; i++)
{
if ((j % 2) != 0)
{
g_matrix[i][j] = 0xFF;
}
else
{
g_matrix[i][j] = 0x00;
}
}
}
res = max7219_cascade_update();
if (res != 0)
{
max7219_interface_debug_print("max7219: cascade update failed.\n");
return 1;
}
...
(void)max7219_cascade_deinit();
return 0;Online documents: https://www.libdriver.com/docs/max7219/index.html.
Offline documents: /doc/html/index.html.
Please refer to CONTRIBUTING.md.
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