u32 InputWait() {
static u64 delay = 0;
u32 pad_state_old = HID_STATE;
delay = (delay) ? 72 : 128;
timer_start();
while (true) {
u32 pad_state = HID_STATE;
if (!(pad_state & BUTTON_ANY)) { // no buttons pressed
u32 special_key = i2cReadRegister(I2C_DEV_MCU, 0x10);
if (special_key == 0x01)
return pad_state | BUTTON_POWER;
else if (special_key == 0x04)
return pad_state | BUTTON_HOME;
pad_state_old = pad_state;
delay = 0;
continue;
}
if ((pad_state == pad_state_old) &&
(!(pad_state & BUTTON_ARROW) ||
(delay && (timer_msec() < delay))))
continue;
// make sure the key is pressed
u32 t_pressed = 0;
for(; (t_pressed < 0x13000) && (pad_state == HID_STATE); t_pressed++);
if (t_pressed >= 0x13000)
return pad_state;
}
}
bool uart_consume_timeout(uint8_t* buffer, uint16_t timeout) {
timer_reset();
while (uart_rx_start == uart_rx_end) {
if (timer_msec() >= timeout) { return false; }
}
*buffer = uart_rx_buf[uart_rx_start];
uart_rx_start = (uart_rx_start +1) % UART_RING_LEN;
return true;
}
/**
* Play one round of the contention game. If neither side received the force_master flag,
* they each wait a random amount of time before sending the ping packet. The first to acknowledge
* the other side's ping is the slave. If the two packets conflict, the came ends in a conflict and
* must be run again.
* If after a timeout passes no token has been received, the device assumes that the pad has
* been snapped and is disconnected from its twin.
* @param usb_present gives the usb-connected side precedence if force_master is not set.
*/
ConnectionState uart_play_round(bool force_master, bool usb_present) {
timer_reset();
uint16_t ms = 0;
while (timer_msec() < 1) {} // let uarts settle
if (!force_master) {
hwrng_start();
timer_reset(); while (timer_msec() < 2) {} // wait 2 ms
while (!hwrng_done()) {} // wait for random data to become available
if (!usb_present) {
ms = 3+(hwrng_bits()[0] & 0x3f); // additional delay of 3-67 ms
} else {
ms = 0; // skip additional delay on usb-connected end
}
}
timer_reset();
while (timer_msec() < ms) {
if (uart_has_data()) {
uint8_t b = uart_consume();
if (b == UTOK_GAME_PING) {
uart_send_byte(UTOK_GAME_ACK);
return CS_TWINNED_SLAVE;
} else if (b == UTOK_GAME_ACK) {
return CS_TWINNED_COLLISION;
}
}
}
uart_send_byte(UTOK_GAME_PING);
timer_reset();
ms = 1000 - ms;
while (timer_msec() < ms) {
if (uart_has_data()) {
uint8_t b = uart_consume();
if (b == UTOK_GAME_ACK) {
return CS_TWINNED_MASTER;
} else if (b == UTOK_GAME_PING) {
return CS_TWINNED_COLLISION;
}
}
}
return CS_SINGLE;
}
