qmk-firmware/keyboards/kinesis/kint41/kint41.c
rockybulwinkle fb150e08f1
[Keyboard] Increase kinesis/kint41 unselect delay ()
* [Keyboard] Increase kinesis/kint41 unselect delay

Fixes 

* Update kint41.c

Use correct si-abbreviation for micro in comment.
2022-08-13 03:38:01 +01:00

57 lines
2.1 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Copyright 2020 QMK
*
* 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 2 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 "kint41.h"
#define LED_POWER LINE_PIN13
void matrix_init_kb(void) {
matrix_init_user();
// Turn on the Teensy 4.x Power LED:
setPinOutput(LED_POWER);
writePinHigh(LED_POWER);
}
// delay_inline sleeps for |cycles| (e.g. sleeping for F_CPU will sleep 1s).
// delay_inline assumes the cycle counter has already been initialized and
// should not be modified, i.e. it is safe to call during keyboard matrix scan.
//
// ChibiOS enables the cycle counter in chcore_v7m.c:
// https://github.com/ChibiOS/ChibiOS/blob/b63023915c304092acb9f33bbab40f3ec07a7f0e/os/common/ports/ARMCMx/chcore_v7m.c#L263
static void delay_inline(const uint32_t cycles) {
const uint32_t start = DWT->CYCCNT;
while ((DWT->CYCCNT - start) < cycles) {
// busy-loop until time has passed
}
}
void matrix_output_unselect_delay(uint8_t line, bool key_pressed) {
// Use the cycle counter to do precise timing in microseconds. The ChibiOS
// thread sleep functions only allow sleep durations starting at 1 tick, which
// is 100μs in our configuration.
// Empirically: e.g. 5μs is not enough, will result in keys that dont work
// and ghost key presses. 10μs seems to work well.
// On some variants of the hardware, 20μs seems to be required. This was found
// on a combination of KB600LF+stapelberg v2020-06-30+teensy41.
// 600 cycles at 0.6 cycles/ns == 1μs
const uint32_t cycles_per_us = 600;
delay_inline(20 * cycles_per_us);
}