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Improved T-Deck trackball responsiveness #276

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Merged
bmorcelli merged 1 commit into from
Feb 19, 2026
Merged

Improved T-Deck trackball responsiveness #276

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71 changes: 33 additions & 38 deletions boards/lilygo-t-deck/interface.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -15,33 +15,34 @@ void IRAM_ATTR ISR_down();
void IRAM_ATTR ISR_left();
void IRAM_ATTR ISR_right();

volatile bool trackball_interrupted = false;
volatile int8_t trackball_up_count = 0;
volatile int8_t trackball_down_count = 0;
volatile int8_t trackball_left_count = 0;
volatile int8_t trackball_right_count = 0;
volatile int8_t trackball_axis_x = 0;
volatile int8_t trackball_axis_y = 0;
volatile uint32_t trackball_axis_expiry_ms = 0;

#define TRACKBALL_THRESHOLD 2
#define TRACKBALL_AXIS_COOLDOWN_MS 250
#define TRACKBALL_AXIS_THRESHOLD 2

void IRAM_ATTR ISR_up() {
if (++trackball_up_count >= TRACKBALL_THRESHOLD) trackball_interrupted = true;
trackball_axis_y > 0 ? trackball_axis_y = -1 : --trackball_axis_y;
trackball_axis_expiry_ms = millis() + TRACKBALL_AXIS_COOLDOWN_MS;
}
void IRAM_ATTR ISR_down() {
if (++trackball_down_count >= TRACKBALL_THRESHOLD) trackball_interrupted = true;
trackball_axis_y < 0 ? trackball_axis_y = 1 : ++trackball_axis_y;
trackball_axis_expiry_ms = millis() + TRACKBALL_AXIS_COOLDOWN_MS;
}
void IRAM_ATTR ISR_left() {
if (++trackball_left_count >= TRACKBALL_THRESHOLD) trackball_interrupted = true;
trackball_axis_x > 0 ? trackball_axis_x = -1 : --trackball_axis_x;
trackball_axis_expiry_ms = millis() + TRACKBALL_AXIS_COOLDOWN_MS;
}
void IRAM_ATTR ISR_right() {
if (++trackball_right_count >= TRACKBALL_THRESHOLD) trackball_interrupted = true;
trackball_axis_x < 0 ? trackball_axis_x = 1 : ++trackball_axis_x;
trackball_axis_expiry_ms = millis() + TRACKBALL_AXIS_COOLDOWN_MS;
}

void ISR_rst() {
trackball_up_count = 0;
trackball_down_count = 0;
trackball_left_count = 0;
trackball_right_count = 0;
trackball_interrupted = false;
trackball_axis_x = 0;
trackball_axis_y = 0;
trackball_axis_expiry_ms = 0;
}

#define LILYGO_KB_SLAVE_ADDRESS 0x55
Expand All @@ -51,10 +52,11 @@ void ISR_rst() {
#define SEL_BTN 0
#define UP_BTN 3
#define DW_BTN 15
#define L_BTN 2
#define R_BTN 1
#define L_BTN 1
#define R_BTN 2
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@mean-ui-thread mean-ui-thread Feb 8, 2026

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I noticed that left was positive and right was negative before. Still wondering why left and right were inverted here...

I even checked in LilyGo's T-Deck example code, and left is 1, right is 2:

https://github.com/Xinyuan-LilyGO/T-Deck/blob/651631d789b7aca4378333ece196409078b3f053/examples/LvglArduinoVNC_VGA/TDECK_PINS.h#L31-L32

If you perfer keeping left and right inverted, please let me know. I just changed this to make it more intuitive but it's not a big deal if you prefer left as positive on X

#define PIN_POWER_ON 10
#define BOARD_TOUCH_INT 16

/***************************************************************************************
** Function name: _setup_gpio()
** Location: main.cpp
Expand Down Expand Up @@ -161,30 +163,23 @@ void InputHandler(void) {
}
if (millis() - tm < 200 && !LongPress) return;

// 0 - UP
// 1 - Down
// 2 - Left
// 3 - Right
if (trackball_interrupted) {
uint8_t xx = 1;
uint8_t yy = 1;
xx += trackball_left_count ? 1 : 0;
xx -= trackball_right_count ? 1 : 0;
yy -= trackball_up_count ? 1 : 0;
yy += trackball_down_count ? 1 : 0;
if (xx == 1 && yy == 1) {
ISR_rst();
} else {
if (!wakeUpScreen()) AnyKeyPress = true;
else return;
}
// Print "bot - xx - yy", 1 is normal value for xx and yy 0 and 2 means movement on the axis
// Serial.print(bot); Serial.print("-"); Serial.print(xx); Serial.print("-"); Serial.println(yy);
if (xx < 1 || yy < 1) {
// if the trackball movement has expired, reset it to avoid unwanted movements
if (trackball_axis_expiry_ms && trackball_axis_expiry_ms <= millis()) { ISR_rst(); }

if (abs(trackball_axis_x) >= TRACKBALL_AXIS_THRESHOLD ||
abs(trackball_axis_y) >= TRACKBALL_AXIS_THRESHOLD) {

if (!wakeUpScreen()) AnyKeyPress = true;
else return;

// Serial.print("Trackball: [");
// Serial.print(trackball_axis_x); Serial.print(", "); Serial.print(trackball_axis_y);
// Serial.println("]");
if (trackball_axis_x < 0 || trackball_axis_y < 0) {
ISR_rst();
PrevPress = true;
} // left , Up
else if (xx > 1 || yy > 1) {
else if (trackball_axis_x > 0 || trackball_axis_y > 0) {
ISR_rst();
NextPress = true;
} // right, Down
Expand Down
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