Atmel SAM4S开发套件体验2之OLED板

renegade · 发表于 2014-12-1 22:45:06

这一篇文章主要讲Atmel开发板套件上OLED的使用。
先介绍一下OLED的特性：OLED显示技术具有自发光的特性，采用非常薄的有机材料涂层和玻璃基板，当有电流通过时，这些有机材料就会发光，而且OLED显示屏幕可视角度大，并且能够节省电能，从2003年开始这种显示设备在MP3播放器上得到了应用。三星手机的屏幕就是用的OLED屏哦。

我们先按照官方用户指南的顺序看看这块板子
这是Xplained Pro 的身份牌，嘿嘿，就是通过这个，你可以通过MCU识别出这块配套板子的基础信息。

第一个是厂家名称，然后依次是产品名，版本号，产品序列号，最小电压，最大电压，以及最大电流值。
下面这个是这块板子的引脚接口，第一个是Id，也就是上面说的身份牌，第二个gnd接地端口，然后是两路ADC接口，然后是两个GPIO口，然后是一个Pwm输出口，9是可以作为中断口,10号可以用作SPI串行通信，11号作为数据线，12号作为时钟线，13，14分别是串口的Tx，rx引脚，15~18是用SPI的，19，20分别是vcc，gnd

然后我们只需要按照顺序操作这些引脚即可。
我们上一段代码分析分析：
#ifndef CONF_SSD1306_H_INCLUDED#define CONF_SSD1306_H_INCLUDED一开始是一段宏定义，帮助大家跟好的理解这段代码的。// Interface configuration for SAM4S Xplained Pro#define SSD1306_SPI_INTERFACE#define SSD1306_SPI SPI#define SSD1306_DC_PIN UG_2832HSWEG04_DATA_CMD_GPIO#define SSD1306_RES_PIN UG_2832HSWEG04_RESET_GPIO#define SSD1306_CS_PIN UG_2832HSWEG04_SS// Minimum clock period is 50ns@3.3V -> max frequency is 20MHz#define SSD1306_CLOCK_SPEED UG_2832HSWEG04_BAUDRATE#define SSD1306_DISPLAY_CONTRAST_MAX 40#define SSD1306_DISPLAY_CONTRAST_MIN 30#endif /* CONF_SSD1306_H_INCLUDED */#include "ssd1306.h"#include "font.h"/** * \internal * \brief Initialize the hardware interface * * Depending on what interface used for interfacing the OLED controller this * function will initialize the necessary hardware. */这一段主要是调用的官方的底层库函数写的，方面简洁，主要是配置SPIstatic void ssd1306_interface_init(void){#ifdef SSD1306_SERIAL_INTERFACE spi_flags_t spi_flags = SPI_MODE_0; board_spi_select_id_t spi_select_id = 0;#endif#if defined(SSD1306_USART_SPI_INTERFACE) struct usart_spi_device device = { .id = SSD1306_CS_PIN, }; usart_spi_init(SSD1306_USART_SPI); usart_spi_setup_device(SSD1306_USART_SPI, &device, spi_flags, SSD1306_CLOCK_SPEED, spi_select_id);#elif defined(SSD1306_SPI_INTERFACE) struct spi_device device = { .id = SSD1306_CS_PIN, }; spi_master_init(SSD1306_SPI); spi_master_setup_device(SSD1306_SPI, &device, spi_flags, SSD1306_CLOCK_SPEED, spi_select_id);#ifdef SAM spi_enable(SSD1306_SPI);#endif#endif}/** * \brief Initialize the OLED controller * * Call this function to initialize the hardware interface and the OLED * controller. When initialization is done the display is turned on and ready * to receive data. */下面这一段是对oled屏幕的初始化设置void ssd1306_init(void){ // Do a hard reset of the OLED display controller ssd1306_hard_reset(); // Initialize the interface ssd1306_interface_init(); // 1/32 Duty (0x0F~0x3F) ssd1306_write_command(SSD1306_CMD_SET_MULTIPLEX_RATIO); ssd1306_write_command(0x1F); // Shift Mapping RAM Counter (0x00~0x3F) ssd1306_write_command(SSD1306_CMD_SET_DISPLAY_OFFSET); ssd1306_write_command(0x00); // Set Mapping RAM Display Start Line (0x00~0x3F) ssd1306_write_command(SSD1306_CMD_SET_START_LINE(0x00)); // Set Column Address 0 Mapped to SEG0 ssd1306_write_command(SSD1306_CMD_SET_SEGMENT_RE_MAP_COL127_SEG0); // Set COM/Row Scan Scan from COM63 to 0 ssd1306_write_command(SSD1306_CMD_SET_COM_OUTPUT_SCAN_DOWN); // Set COM Pins hardware configuration ssd1306_write_command(SSD1306_CMD_SET_COM_PINS); ssd1306_write_command(0x02); ssd1306_set_contrast(0x8F); // Disable Entire display On ssd1306_write_command(SSD1306_CMD_ENTIRE_DISPLAY_AND_GDDRAM_ON); ssd1306_display_invert_disable(); // Set Display Clock Divide Ratio / Oscillator Frequency (Default => 0x80) ssd1306_write_command(SSD1306_CMD_SET_DISPLAY_CLOCK_DIVIDE_RATIO); ssd1306_write_command(0x80); // Enable charge pump regulator ssd1306_write_command(SSD1306_CMD_SET_CHARGE_PUMP_SETTING); ssd1306_write_command(0x14); // Set VCOMH Deselect Level ssd1306_write_command(SSD1306_CMD_SET_VCOMH_DESELECT_LEVEL); ssd1306_write_command(0x40); // Default => 0x20 (0.77*VCC) // Set Pre-Charge as 15 Clocks & Discharge as 1 Clock ssd1306_write_command(SSD1306_CMD_SET_PRE_CHARGE_PERIOD); ssd1306_write_command(0xF1); ssd1306_display_on();}/** * \brief Display text on OLED screen. * \param string String to display. */void ssd1306_write_text(const char *string){ uint8_t *char_ptr; uint8_t i; while (*string != 0) { if (*string < 0x7F) { char_ptr = font_table[*string - 32]; for (i = 1; i <= char_ptr[0]; i++) { ssd1306_write_data(char_ptr); } ssd1306_write_data(0x00); } string++; }}配置完了，可以调用这里的函数对oled进行操作了，文章开头就是用oled显示内存卡容量以及内容的哦。

​Atmel SAM4S开发套件体验2之OLED板

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Atmel SAM4S开发套件体验2之OLED板