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ssd1309: Fix corruption in last column of 2.42" 128x64 displays.

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Seems to be due to last data byte in a transaction being dropped.
One fix was to introduce 100us delay between BTF and STOP in
i2c_btf_stop(). The workaround here is simply to clear that column
during oled init. With 6x13 font it is always blank anyway.
This commit is contained in:
Keir Fraser 2020-09-20 08:08:14 +01:00
parent e22bb5709d
commit 07953affa5
1 changed files with 17 additions and 3 deletions
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20
src/display/lcd.c
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@ -771,7 +771,7 @@ static unsigned int oled_start_i2c(uint8_t *buf)
static const uint8_t ssd1306_addr_cmds[] = { static const uint8_t ssd1306_addr_cmds[] = {
0x20, 0, /* horizontal addressing mode */ 0x20, 0, /* horizontal addressing mode */
0x21, 0, 127, /* column address range: 0-127 */ 0x21, 0, 127, /* column address range: 0-127 */
0x22, 0, /*?*//* page address range: 0-? */ 0x22, 0, 7, /* page address range: 0-7 */
}, ztech_addr_cmds[] = { }, ztech_addr_cmds[] = {
0xda, 0x12, /* alternate com pins config */ 0xda, 0x12, /* alternate com pins config */
0x21, 4, 131, /* column address range: 4-131 */ 0x21, 4, 131, /* column address range: 4-131 */
@ -791,8 +791,6 @@ static unsigned int oled_start_i2c(uint8_t *buf)
*dc++ = 0xb0 + i2c_row; *dc++ = 0xb0 + i2c_row;
} else { } else {
p += oled_queue_cmds(p, ssd1306_addr_cmds, sizeof(ssd1306_addr_cmds)); p += oled_queue_cmds(p, ssd1306_addr_cmds, sizeof(ssd1306_addr_cmds));
/* Page address max: depends on display height */
*dc++ = (oled_height / 8) - 1;
} }
/* Display on/off according to backlight setting. */ /* Display on/off according to backlight setting. */
@ -987,6 +985,10 @@ static void oled_init(void)
}, rot_cmds[] = { }, rot_cmds[] = {
0xa0, /* segment mapping (default) */ 0xa0, /* segment mapping (default) */
0xc0, /* com scan direction (default) */ 0xc0, /* com scan direction (default) */
}, ssd1306_cls_cmds[] = {
0x20, 1, /* vertical addressing mode */
0x21, 127, 127, /* column address range: 127-127 */
0x22, 0, 7, /* page address range: 0-7 */
}; };
const uint8_t *cmds; const uint8_t *cmds;
uint8_t dynamic_cmds[6], *dc; uint8_t dynamic_cmds[6], *dc;
@ -1022,6 +1024,18 @@ static void oled_init(void)
cmds = (ff_cfg.display_type & DISPLAY_rotate) ? rot_cmds : norot_cmds; cmds = (ff_cfg.display_type & DISPLAY_rotate) ? rot_cmds : norot_cmds;
p += oled_queue_cmds(p, cmds, sizeof(rot_cmds)); p += oled_queue_cmds(p, cmds, sizeof(rot_cmds));
if (oled_model == OLED_ssd1306) {
/* Clear last column of pixels. This works around an issue seen on
* SSD1309 128x64 displays where the last data byte in a transaction
* can be lost. This is less visible if that screen area is blank. */
int i;
p += oled_queue_cmds(p, ssd1306_cls_cmds, sizeof(ssd1306_cls_cmds));
for (i = 0; i < 8; i++) {
*p++ = 0xc0; /* Data */
*p++ = 0;
}
}
/* Start off the I2C transaction. */ /* Start off the I2C transaction. */
p += oled_start_i2c(p); p += oled_start_i2c(p);