implement mode history

3 files changed, 8 insertions, 0 deletions

diff --git a/shared/consts.h b/shared/consts.h
index f9d4c11..25ca94f 100644
--- a/shared/consts.h
+++ b/shared/consts.h
@@ -17,3 +17,5 @@
 #define W2_SERIAL_READ_BUFFER_SIZE (255)
 /** exponential moving average new measurement weight (double 0-1) */
 #define W2_EMA_WEIGHT (0.10)
+/** size of mode history buffer */
+#define W2_MODE_HISTORY_BUFFER_SIZE (4)
diff --git a/shared/errors.h b/shared/errors.h
index 44b29a0..ac8e95f 100644
--- a/shared/errors.h
+++ b/shared/errors.h
@@ -47,6 +47,8 @@ typedef enum {
 	W2_E_WARN_SERIAL_TIMEOUT = 0x08 | W2_E_TYPE_WARN,
 	/** unknown message encountered (noisy channel?) */
 	W2_E_WARN_SERIAL_NOISY = 0x09 | W2_E_TYPE_WARN,
+	/** mode history index out of bounds */
+	W2_E_WARN_MODE_HISTORY_BUFFER_IOB = 0x0a | W2_E_TYPE_WARN,
 } w2_e_errorcode;
 
 /**
diff --git a/shared/util.h b/shared/util.h
index 95f4c68..9e4d8ac 100644
--- a/shared/util.h
+++ b/shared/util.h
@@ -1,3 +1,7 @@
 #pragma once
 
+#define W2_MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define W2_MAX(a, b) (((a) > (b)) ? (a) : (b))
+#define W2_RANGE(min, val, max) W2_MIN(max, W2_MAX(val, min))
+
 unsigned long w2_util_exp_mov_avg(unsigned long current_avg, unsigned long new_meas);