Add support for displays without an external VCC (use internal charge pump)

diff --git a/extdrv/ssd130x_oled_driver.c b/extdrv/ssd130x_oled_driver.c
index f8b2d20..06c0d68 100644 (file)
--- a/extdrv/ssd130x_oled_driver.c
+++ b/extdrv/ssd130x_oled_driver.c
@@ -261,16 +261,23 @@ int ssd130x_display_off(struct oled_display* conf)
 int ssd130x_display_on(struct oled_display* conf)
 {
        int ret = 0;
+       uint8_t val = 0;
 
        /* Display OFF */
-       ret = ssd130x_display_power(conf, SSD130x_DISP_OFF);
+       ret = ssd130x_display_power(conf, SSD130x_DISP_OFF);  /* 0xAE */
        if (ret != 0) {
                return ret;
        }
+       if (conf->charge_pump == SSD130x_INTERNAL_PUMP) {
+               val = SSD130x_CMD_CHARGE_INTERN;
+               ssd130x_send_command(conf, SSD130x_CMD_CHARGE_PUMP, &val, 1); /* 0x8D */
+       }
+
        ret = ssd130x_set_mem_addressing_mode(conf, SSD130x_ADDR_TYPE_HORIZONTAL);
        if (ret != 0) {
                return ret;
        }
+
        ret = ssd130x_set_scan_direction(conf);
        if (ret != 0) {
                return ret;
@@ -279,6 +286,14 @@ int ssd130x_display_on(struct oled_display* conf)
        if (ret != 0) {
                return ret;
        }
+
+       if (conf->charge_pump == SSD130x_INTERNAL_PUMP) {
+               val = 0xF1;
+               ssd130x_send_command(conf, SSD130x_CMD_SET_PRECHARGE, &val, 1); /* 0xD9 */
+               val = SSD130x_VCOM_083;
+               ssd130x_send_command(conf, SSD130x_CMD_VCOM_LEVEL, &val, 1);  /* 0xDB */
+       }
+
        ret = ssd130x_set_display_on(conf, SSD130x_DISP_RAM);
        if (ret != 0) {
                return ret;

diff --git a/include/extdrv/ssd130x_oled_driver.h b/include/extdrv/ssd130x_oled_driver.h
index 19f055d..8552c39 100644 (file)
--- a/include/extdrv/ssd130x_oled_driver.h
+++ b/include/extdrv/ssd130x_oled_driver.h
@@ -33,6 +33,7 @@ struct oled_display {
        uint8_t address; /* 8 bits address */
        uint8_t bus_num; /* I2C bus number */
        uint8_t probe_ok;
+       uint8_t charge_pump;
        uint8_t video_mode;
        uint8_t contrast;
        uint8_t scan_dir;
@@ -121,6 +122,13 @@ enum ssd130x_defs {
 #define SSD130x_ADDR_COL(x)       ((x) & 0x7F)
 #define SSD130x_ADDR_PAGE(x)      ((x) & 0x07)
 
+/* Charge pump */
+#define SSD130x_EXT_VCC       0x01
+#define SSD130x_INTERNAL_PUMP 0x00
+#define SSD130x_CMD_CHARGE_PUMP    0x8D
+#define SSD130x_CMD_CHARGE_EXT     0x10
+#define SSD130x_CMD_CHARGE_INTERN  0x14
+
 /* Hardware configuration */
 #define SSD130x_CMD_START_LINE(x)      (0x40 + ((x) & 0x3F))
 #define SSD130x_CMD_SEG0_MAP_RIGHT     0xA1