From 3c1d050abbeed9803d7f5dac818577e8fd00e3fa Mon Sep 17 00:00:00 2001
From: Dave <dfnum2@gmail.com>
Date: Tue, 12 May 2020 17:09:49 -0500
Subject: [PATCH] Move F_CPU to header file and clean up 2560 read_row() code

---
 firmware/asdf/src/Arch/asdf_arch_atmega2560.c | 16 ++++++++++------
 firmware/asdf/src/Arch/asdf_arch_atmega2560.h |  5 ++++-
 firmware/asdf/src/Arch/asdf_arch_atmega328p.c |  2 +-
 firmware/asdf/src/Arch/asdf_arch_atmega328p.h |  2 ++
 4 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/firmware/asdf/src/Arch/asdf_arch_atmega2560.c b/firmware/asdf/src/Arch/asdf_arch_atmega2560.c
index 3ea6b15..117e17a 100644
--- a/firmware/asdf/src/Arch/asdf_arch_atmega2560.c
+++ b/firmware/asdf/src/Arch/asdf_arch_atmega2560.c
@@ -33,6 +33,7 @@
 // 23-25        PORTC0-2  ROW outputs (row number)
 // 27           PORTC4
 
+#include "asdf_arch.h"
 
 #include <avr/io.h>
 #include <avr/interrupt.h>
@@ -40,7 +41,6 @@
 #include <stdint.h>
 
 #include "asdf_config.h"
-#include "asdf_arch.h"
 #include "asdf_keymap_defs.h"
 
 // Tick is true every 1 ms.
@@ -728,6 +728,10 @@ void asdf_arch_init(void)
 //    "1". So, if a keypress pulls the column line low, then the reading of the
 //    physical bits must be inverted.
 //
+// 2) A small delay (2usec) is required between setting the keyboard row outputs
+//    and reading the columns, which I think is due to capacitance across the
+//    reverse-biased diodes.
+//
 // SCOPE: public
 //
 // COMPLEXITY: 1
@@ -735,13 +739,13 @@ void asdf_arch_init(void)
 asdf_cols_t asdf_arch_read_row(uint8_t row)
 {
   uint32_t rows = ~(1L << row);
-  asdf_cols_t cols;
+
   ASDF_LOROW_PORT = (uint8_t)(rows & 0xff);
   ASDF_HIROW_PORT = (uint8_t)((rows >> 8) & 0xff);
-  cols = ~(asdf_cols_t) ASDF_COLUMNS_PIN;
-  ASDF_HIROW_PORT = 0xff;
-  ASDF_LOROW_PORT = 0xff;
-  return cols;
+
+  _delay_us(ASDF_KEYBOARD_ROW_SETTLING_TIME_US);
+
+  return ~(asdf_cols_t) ASDF_COLUMNS_PIN;
 }
 
 // PROCEDURE: asdf_arch_osi_read_row
diff --git a/firmware/asdf/src/Arch/asdf_arch_atmega2560.h b/firmware/asdf/src/Arch/asdf_arch_atmega2560.h
index 112c67a..6145470 100644
--- a/firmware/asdf/src/Arch/asdf_arch_atmega2560.h
+++ b/firmware/asdf/src/Arch/asdf_arch_atmega2560.h
@@ -33,8 +33,11 @@
 
 // ASDF keyboard definitions:
 
-#define ASDF_STROBE_LENGTH_US 10 // strobe length in microseconds
+#define F_CPU 16000000L
 
+#define ASDF_STROBE_LENGTH_US 10 // strobe length in microseconds
+#define ASDF_KEYBOARD_ROW_SETTLING_TIME_US 2 // time for keyboard capacitance to
+                                             // settle before sampling
 
 // Clock definitions:
 #define SYSCLK_DIV1 0
diff --git a/firmware/asdf/src/Arch/asdf_arch_atmega328p.c b/firmware/asdf/src/Arch/asdf_arch_atmega328p.c
index bf7eb0e..bcc752f 100644
--- a/firmware/asdf/src/Arch/asdf_arch_atmega328p.c
+++ b/firmware/asdf/src/Arch/asdf_arch_atmega328p.c
@@ -33,13 +33,13 @@
 // 23-25        PORTC0-2  ROW outputs (row number)
 // 27           PORTC4
 
+#include "asdf_arch.h"
 
 #include <avr/io.h>
 #include <avr/interrupt.h>
 #include <util/delay.h>
 #include <stdint.h>
 #include "asdf_config.h"
-#include "asdf_arch.h"
 #include "asdf_keymap_defs.h"
 
 static volatile uint8_t tick = 0;
diff --git a/firmware/asdf/src/Arch/asdf_arch_atmega328p.h b/firmware/asdf/src/Arch/asdf_arch_atmega328p.h
index c61e509..46690a0 100644
--- a/firmware/asdf/src/Arch/asdf_arch_atmega328p.h
+++ b/firmware/asdf/src/Arch/asdf_arch_atmega328p.h
@@ -33,6 +33,8 @@
 
 // ASDF keyboard definitions:
 
+#define F_CPU 8000000L
+
 #define ASDF_STROBE_LENGTH_US 10 // strobe length in microseconds