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LibDriver MAX7219
The MAX7219/MAX7221 are compact, serial input/output common-cathode display drivers that interface microprocessors (mPs) 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(tm), QSPI(tm), and MICROWIRE(tm), and has slewrate-limited segment drivers to reduce EMI. A convenient 4-wire serial interface connects to all common mPs. 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 150mA 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 a full-featured driver for MAX7219, launched by LibDriver.It provides digital tube display, dot matrix display, cascade display and additional features. LibDriver is MISRA compliant.
Table of Contents
- Instruction
- Install
- Usage
- example basic
- example cascade
- Document
- Contributing
- License
- Contact Us
Instruction
/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.
Install
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.
Usage
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.
example basic
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
example cascade
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;
Document
Online documents: https://www.libdriver.com/docs/max7219/index.html.
Offline documents: /doc/html/index.html.
Contributing
Please refer to CONTRIBUTING.md.
License
Copyright (c) 2015 - present LibDriver All rights reserved
The MIT License (MIT)
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, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
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.
Contact Us
Please send an e-mail to lishifenging@outlook.com.