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Diffstat (limited to 'keyboards/sol/common/knob_v2.c')
-rw-r--r--keyboards/sol/common/knob_v2.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/keyboards/sol/common/knob_v2.c b/keyboards/sol/common/knob_v2.c
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index 0000000000..f22f7c5d86
--- /dev/null
+++ b/keyboards/sol/common/knob_v2.c
@@ -0,0 +1,71 @@
+#include "knob_v2.h"
+
+bool knob_prev_a = false;
+static knob_report_t knob_report = {.dir = 0, .phase = 0};
+
+void knob_init(void) {
+ // I use pins D1 (ISR1) & D4 for a knob.
+
+ // Set pin mode for D4 as input.
+ DDRD &= ~(0UL << ENCODER_PIN_2);
+
+ // Enable internal pull-up for D4.
+ // This is done by "writing" 1 to a pin that has its mode set to input.
+ PORTD |= (1 << ENCODER_PIN_2);
+
+ // Enable interrupt for D1
+ // For more info on the below flags see this awesome section 11.1 (pages 89-90) here:
+ // https://cdn-shop.adafruit.com/datasheets/atmel-7766-8-bit-avr-atmega16u4-32u4_datasheet.pdf
+ // Set pin mode & pull-up.
+ DDRD &= ~(0UL << ENCODER_PIN_1);
+ PORTD |= (1UL << ENCODER_PIN_1);
+
+ // INT: 33221100
+ EICRA |= 0b00010000; // 0b01 - any edge
+ // INT: 6 3210
+ EIMSK |= 0b00000100;
+}
+
+ISR(ENCODER_INT) {
+ bool a = PIND & (1 << ENCODER_PIN_1);
+
+ if (knob_prev_a != a) {
+ // "A" channel has REALLY changed.
+ knob_report.phase = a;
+ knob_prev_a = a;
+ bool b = PIND & (1 << ENCODER_PIN_2);
+ if (a == b) {
+ // Halfway through CCW rotation (A == B)
+ //
+ // +---YOU ARE HERE (A=1, B=1)
+ // | +---OR HERE (A=0, B=0)
+ // | |
+ // v v
+ // A: _____/^^^^^\__
+ // B: __/^^^^^\_____
+ knob_report.dir++;
+ } else {
+ // Halfway through CW rotation (A != B)
+ //
+ // +---YOU ARE HERE (A=1, B=0)
+ // | +---OR HERE (A=0, B=1)
+ // | |
+ // v v
+ // A: _____/^^^^^\_____
+ // B: ________/^^^^^\__
+ knob_report.dir--;
+ }
+ }
+}
+
+knob_report_t knob_report_read(void) {
+ // Return knob report.
+ return knob_report;
+}
+
+void knob_report_reset(void) {
+ // Call this ASAP once you've processed the previous knob report.
+ // TODO: This should probably be called within `knob_report_read`.
+ knob_report.dir = 0;
+ knob_report.phase = 0;
+}