From: tmk <hasu@tmk-kbd.com>
Date: Sat, 28 Dec 2019 13:39:54 +0000 (+0900)
Subject: alps64: Fix for delay time for matrix scan
X-Git-Url: https://git.friedersdorff.com/?a=commitdiff_plain;h=ba4f28a484a670b794674d694998fed4d25f0f5f;p=max%2Ftmk_keyboard.git

alps64: Fix for delay time for matrix scan

Delay less than 20us can cause false key detection in some situations.
With week internal pull-up takes time to charge stray capacitance of
trace between ground fill(and fingers), perhaps?

In particular, when testing Alps64 PCB without diodes tweezer is used
to close a key and this makes trace longer, more capacitance in result.
---

diff --git a/keyboard/alps64/matrix.c b/keyboard/alps64/matrix.c
index 4a1c84c6..1082773f 100644
--- a/keyboard/alps64/matrix.c
+++ b/keyboard/alps64/matrix.c
@@ -72,7 +72,7 @@ uint8_t matrix_scan(void)
 {
     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
         select_row(i);
-        _delay_us(1);  // delay for settling
+        _delay_us(30);  // delay for settling
         matrix_row_t cols = read_cols();
         if (matrix_debouncing[i] != cols) {
             if (debouncing) {