ardupilot/libraries/AP_Notify/Display_SSD1306_I2C.cpp

162 lines
5.5 KiB
C++

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "Display_SSD1306_I2C.h"
#include <utility>
#include <AP_HAL/AP_HAL.h>
#include <AP_HAL/I2CDevice.h>
static const AP_HAL::HAL& hal = AP_HAL::get_HAL();
// constructor
Display_SSD1306_I2C::Display_SSD1306_I2C(AP_HAL::OwnPtr<AP_HAL::Device> dev) :
_dev(std::move(dev))
{
_displaybuffer_sem = hal.util->new_semaphore();
}
bool Display_SSD1306_I2C::hw_init()
{
struct PACKED {
uint8_t reg;
uint8_t seq[31];
} init_seq = { 0x0, {
// LEGEND:
// *** is out of sequence for init steps recommended in datasheet
// +++ not listed in sequence for init steps recommended in datasheet
0xAE, // Display OFF
0xD5, 0x80, // *** Set Display Clock Divide Ratio and Oscillator Frequency
// Clock Divide Ratio: 0b (== 1)
// Oscillator Frequency: 1000b (== +0%)
0xA8, 0x3F, // MUX Ratio: 111111b (== 64MUX)
0xD3, 0x00, // Display Offset: 0b (== 0)
0x40, // Display Start Line: 0b (== 0)
0x8D, 0x14, // *** Enable charge pump regulator: 1b (== Enable)
0x20, 0x00, // *** Memory Addressing Mode: 00b (== Horizontal Addressing Mode)
0xA1, // Segment re-map: 1b (== column address 127 is mapped to SEG0)
0xC8, // COM Output Scan Direction: 1b (== remapped mode. Scan from COM[N-1] to COM0)
0xDA, 0x12, // COM Pins hardware configuration: 01b (POR)
// (== Alternative COM pin configuration + Disable COM Left/Right remap)
0x81, 0xCF, // Contrast Control: 0xCF (== 207 decimal, range 0..255)
0xD9, 0xF1, // +++ Pre-charge Period: 0xF1 (== 1 DCLK P1 + 15 DCLK P2)
0xDB, 0x40, // +++ VCOMH Deselect Level: 100b (INVALID?!) (== ?!)
0xA4, // Entire Display ON (ignoring RAM): (== OFF)
0xA6, // Normal/Inverse Display: 0b (== Normal)
0xAF, // Display ON: 1b (== ON)
0x21, 0, 127, // +++ Column Address: (== start:0, end:127)
0x22, 0, 7 // +++ Page Address: (== start:0, end:7)
} };
memset(_displaybuffer, 0, SSD1306_COLUMNS * SSD1306_ROWS_PER_PAGE);
// take i2c bus semaphore
if (!_dev || !_dev->get_semaphore()->take(HAL_SEMAPHORE_BLOCK_FOREVER)) {
return false;
}
// init display
bool success = _dev->transfer((uint8_t *)&init_seq, sizeof(init_seq), nullptr, 0);
// give back i2c semaphore
_dev->get_semaphore()->give();
if (success) {
_need_hw_update = true;
_dev->register_periodic_callback(20000, FUNCTOR_BIND_MEMBER(&Display_SSD1306_I2C::_timer, void));
}
return success;
}
void Display_SSD1306_I2C::hw_update()
{
_need_hw_update = true;
}
void Display_SSD1306_I2C::_timer()
{
if (!_need_hw_update) {
return;
}
_need_hw_update = false;
struct PACKED {
uint8_t reg;
uint8_t cmd[6];
} command = { 0x0, {0x21, 0, 127, 0x22, 0, 7} };
struct PACKED {
uint8_t reg;
uint8_t db[SSD1306_COLUMNS/2];
} display_buffer = { 0x40, {} };
// write buffer to display
for (uint8_t i = 0; i < (SSD1306_ROWS / SSD1306_ROWS_PER_PAGE); i++) {
command.cmd[4] = i;
_dev->transfer((uint8_t *)&command, sizeof(command), nullptr, 0);
if (_displaybuffer_sem->take(0)) {
memcpy(&display_buffer.db[0], &_displaybuffer[i * SSD1306_COLUMNS], SSD1306_COLUMNS/2);
_displaybuffer_sem->give();
_dev->transfer((uint8_t *)&display_buffer, SSD1306_COLUMNS/2 + 1, nullptr, 0);
}
if (_displaybuffer_sem->take(0)) {
memcpy(&display_buffer.db[0], &_displaybuffer[i * SSD1306_COLUMNS + SSD1306_COLUMNS/2 ], SSD1306_COLUMNS/2);
_displaybuffer_sem->give();
_dev->transfer((uint8_t *)&display_buffer, SSD1306_COLUMNS/2 + 1, nullptr, 0);
}
}
}
void Display_SSD1306_I2C::set_pixel(uint16_t x, uint16_t y)
{
// check x, y range
if ((x >= SSD1306_COLUMNS) || (y >= SSD1306_ROWS)) {
return;
}
if (!_displaybuffer_sem->take(0)) {
return;
}
// set pixel in buffer
_displaybuffer[x + (y / 8 * SSD1306_COLUMNS)] |= 1 << (y % 8);
_displaybuffer_sem->give();
}
void Display_SSD1306_I2C::clear_pixel(uint16_t x, uint16_t y)
{
// check x, y range
if ((x >= SSD1306_COLUMNS) || (y >= SSD1306_ROWS)) {
return;
}
if (!_displaybuffer_sem->take(0)) {
return;
}
// clear pixel in buffer
_displaybuffer[x + (y / 8 * SSD1306_COLUMNS)] &= ~(1 << (y % 8));
_displaybuffer_sem->give();
}
void Display_SSD1306_I2C::clear_screen()
{
if (!_displaybuffer_sem->take(0)) {
return;
}
memset(_displaybuffer, 0, SSD1306_COLUMNS * SSD1306_ROWS_PER_PAGE);
_displaybuffer_sem->give();
}