Optimizing I2C

This commit is contained in:
Oleg Kostyuk 2013-09-09 01:49:11 +03:00
parent 777d1fba76
commit 5329bbefee
4 changed files with 49 additions and 33 deletions

View file

@ -40,7 +40,17 @@ Project located at <https://github.com/benblazak/ergodox-firmware>
//#define MATRIX_HAS_GHOST
/* Set 0 if debouncing isn't needed */
#define DEBOUNCE 5
/*
* This constant define not debouncing time in msecs, but amount of matrix
* scan loops which should be made to get stable debounced results.
*
* On Ergodox matrix scan rate is relatively low, because of slow I2C.
* Now it's only 317 scans/second, or about 3.15 msec/scan.
* According to Cherry specs, debouncing time is 5 msec.
*
* And so, there is no sense to have DEBOUNCE higher than 2.
*/
#define DEBOUNCE 2
/* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
#define LOCKING_SUPPORT_ENABLE

View file

@ -90,6 +90,7 @@ uint8_t init_mcp23018(void) {
err = i2c_write(0b00000000); if (err) goto out;
err = i2c_write(0b00111111); if (err) goto out;
i2c_stop();
// set pull-up
// - unused : on : 1
// - input : on : 1
@ -98,8 +99,18 @@ uint8_t init_mcp23018(void) {
err = i2c_write(GPPUA); if (err) goto out;
err = i2c_write(0b00000000); if (err) goto out;
err = i2c_write(0b00111111); if (err) goto out;
out:
i2c_stop();
if (!err) err = ergodox_left_leds_update();
return err;
}
uint8_t ergodox_left_leds_update(void) {
uint8_t err = 0x20;
// set logical value (doesn't matter on inputs)
// - unused : hi-Z : 1
// - input : hi-Z : 1

View file

@ -47,6 +47,7 @@ Most used files are located at
void init_ergodox(void);
uint8_t init_mcp23018(void);
uint8_t ergodox_left_leds_update(void);
#define LED_BRIGHTNESS_LO 31
#define LED_BRIGHTNESS_HI 255
@ -75,8 +76,6 @@ inline void ergodox_left_led_1_off(void) { ergodox_left_led_1 = 0; }
inline void ergodox_left_led_2_off(void) { ergodox_left_led_2 = 0; }
inline void ergodox_left_led_3_off(void) { ergodox_left_led_3 = 0; }
inline void ergodox_left_leds_update(void) { init_mcp23018(); }
inline void ergodox_led_all_on(void)
{
ergodox_board_led_on();

View file

@ -42,10 +42,12 @@ static uint8_t debouncing = DEBOUNCE;
static matrix_row_t matrix[MATRIX_ROWS];
static matrix_row_t matrix_debouncing[MATRIX_ROWS];
static matrix_row_t read_cols(uint8_t mcp23018_status, uint8_t row);
static matrix_row_t read_cols(uint8_t row);
static void init_cols(void);
static void unselect_rows(uint8_t mcp23018_status);
static void select_row(uint8_t mcp23018_status, uint8_t row);
static void unselect_rows();
static void select_row(uint8_t row);
static uint8_t mcp23018_status;
#ifdef DEBUG_MATRIX_FREQ
uint32_t matrix_timer;
@ -68,9 +70,8 @@ void matrix_init(void)
{
// initialize row and col
init_ergodox();
uint8_t mcp23018_status;
mcp23018_status = init_mcp23018();
unselect_rows(mcp23018_status);
unselect_rows();
init_cols();
// initialize matrix state: all keys off
@ -139,16 +140,14 @@ uint8_t matrix_scan(void)
}
// not actually needed because we already calling init_mcp23018() in next line
// ergodox_left_leds_update();
mcp23018_status = ergodox_left_leds_update();
#endif
uint8_t mcp23018_status = init_mcp23018();
for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
select_row(mcp23018_status, i);
select_row(i);
_delay_us(30); // without this wait read unstable value.
matrix_row_t cols = read_cols(mcp23018_status, i);
matrix_row_t cols = read_cols(i);
if (matrix_debouncing[i] != cols) {
matrix_debouncing[i] = cols;
if (debouncing) {
@ -156,7 +155,7 @@ uint8_t matrix_scan(void)
}
debouncing = DEBOUNCE;
}
unselect_rows(mcp23018_status);
unselect_rows();
}
if (debouncing) {
@ -230,17 +229,16 @@ static void init_cols(void)
PORTF |= (1<<7 | 1<<6 | 1<<5 | 1<<4 | 1<<1 | 1<<0);
}
static matrix_row_t read_cols(uint8_t mcp23018_status, uint8_t row)
static matrix_row_t read_cols(uint8_t row)
{
if (row < 7) {
if (mcp23018_status) { // if there was an error
return 0;
} else {
uint8_t data = 0;
uint8_t err = 0x20;
err = i2c_start(I2C_ADDR_WRITE); if (err) goto out;
err = i2c_write(GPIOB); if (err) goto out;
err = i2c_start(I2C_ADDR_READ); if (err) goto out;
mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out;
mcp23018_status = i2c_write(GPIOB); if (mcp23018_status) goto out;
mcp23018_status = i2c_start(I2C_ADDR_READ); if (mcp23018_status) goto out;
data = i2c_readNak();
data = ~data;
out:
@ -269,19 +267,18 @@ static matrix_row_t read_cols(uint8_t mcp23018_status, uint8_t row)
* row: 0 1 2 3 4 5 6
* pin: A0 A1 A2 A3 A4 A5 A6
*/
static void unselect_rows(uint8_t mcp23018_status)
static void unselect_rows(void)
{
// unselect on mcp23018
if (mcp23018_status) { // if there was an error
// do nothing
} else {
// set all rows hi-Z : 1
uint8_t err = 0x20;
err = i2c_start(I2C_ADDR_WRITE); if (err) goto out;
err = i2c_write(GPIOA); if (err) goto out;
err = i2c_write( 0xFF
& ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
); if (err) goto out;
mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out;
mcp23018_status = i2c_write(GPIOA); if (mcp23018_status) goto out;
mcp23018_status = i2c_write( 0xFF
& ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
); if (mcp23018_status) goto out;
out:
i2c_stop();
}
@ -296,7 +293,7 @@ static void unselect_rows(uint8_t mcp23018_status)
PORTC &= ~(1<<6);
}
static void select_row(uint8_t mcp23018_status, uint8_t row)
static void select_row(uint8_t row)
{
if (row < 7) {
// select on mcp23018
@ -305,12 +302,11 @@ static void select_row(uint8_t mcp23018_status, uint8_t row)
} else {
// set active row low : 0
// set other rows hi-Z : 1
uint8_t err = 0x20;
err = i2c_start(I2C_ADDR_WRITE); if (err) goto out;
err = i2c_write(GPIOA); if (err) goto out;
err = i2c_write( 0xFF & ~(1<<row)
& ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
); if (err) goto out;
mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out;
mcp23018_status = i2c_write(GPIOA); if (mcp23018_status) goto out;
mcp23018_status = i2c_write( 0xFF & ~(1<<row)
& ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
); if (mcp23018_status) goto out;
out:
i2c_stop();
}