Refactor firmware for clarity; no functional changes

- main.c: file-header comment describing the hardware and operation, logic
  split into named phases (sleep_until_interrupt, wake_peripheral_rails,
  take_counts_snapshot, send_wheel_counts_report, handle_minute_alarm,
  init_all_hardware); shared state renamed to say what it is and made static.
- rfm69.c: reorganized into six labeled sections; cond_1/2/3 and hash scratch
  globals replaced by a reply_acknowledges() helper with clear locals; packet
  layout and every init register write documented.
- LOG() macro (compiled out when DO_UART is off) replaces the #if DO_UART
  blocks that obscured the logic.
- Drivers: file-header comments; named RTC_REG_*/RTC_ALM_MASK_BIT constants;
  EEPROM spool scheme documented; ADC_CHANNEL_BANDGAP named; repeated pin
  if/else helpers collapsed to SET_PIN_TO().
- Removed unused globals/buffers and commented-out code; ran clang-format
  with the project style.

Register writes and radio protocol are byte-identical. Builds clean under
-Wall -Wextra on gnu17 and c23; flash 13028 -> 12830 B, static RAM
1038 -> 999 B.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YVJKatfeMJjAmuH9KYiLuv

avr_code/defines.h

@@ -1,4 +1,4 @@
-/* 
+/*
  * File:   defines.h
  * Author: thebears
  *
@@ -6,33 +6,43 @@
  */
 
 #ifndef DEFINES_H
-#define	DEFINES_H
+#define DEFINES_H
 
-#ifdef	__cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
-    
+
 #include "stdint.h"
 
 #include <stdbool.h>
-#include <stdlib.h>
 #include <stdio.h>
+#include <stdlib.h>
 #ifndef F_CPU
 #define F_CPU 8000000UL // 8 MHz clock speed; prefer -DF_CPU=8000000UL in the build flags
 #endif
 #define BAUD 38400
 #define F_SCL 200000UL
 
+// Build switches: DO_UART compiles in serial logging, ITERATING is a bench
+// mode that reports every minute instead of every 15.
 #define DO_UART true
 #define ITERATING false
 
-#define MIN(a,b) (((a)<(b))?(a):(b))
-#define MAX(a,b) (((a)>(b))?(a):(b))
+// Serial log line, compiled out entirely when DO_UART is off. The caller's
+// file must include uart.h (directly or via another driver header).
+#if DO_UART
+#define LOG(msg) uart_sendString(msg)
+#else
+#define LOG(msg) ((void)0)
+#endif
 
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
+// Shared scratch buffers (RAM is tight: 2 KB total). DATA_BUFFER_65 holds one
+// EEPROM page plus a terminator; DATA_BUFFER_7 holds one RTC time readout.
 extern unsigned char DATA_BUFFER_65[65];
 extern uint8_t DATA_BUFFER_7[7];
-//extern uint8_t DATA_BUFFER_254[255];
-extern unsigned char DATA_BUFFER_20[20];
 
 typedef struct {
     uint8_t payload_len;
@@ -56,7 +66,6 @@ typedef struct {
 } identifier_results;
 extern identifier_results IDENTIFIER;
 
-
 typedef struct {
     uint8_t len;
     uint8_t to;
@@ -71,25 +80,22 @@ extern tx_rx_data_struct RX_DATA;
 typedef struct {
     uint8_t Second; // 0-59
     uint8_t Minute; // 0-59
-    uint8_t Hour;   // 0-23
-    uint8_t Wday;   // Day of week, 1-7 (1 = Sunday)
-    uint8_t Day;    // 1-31
-    uint8_t Month;  // 1-12
-    uint8_t Year;   // Full year (e.g., 2024)
+    uint8_t Hour; // 0-23
+    uint8_t Wday; // Day of week, 1-7 (1 = Sunday)
+    uint8_t Day; // 1-31
+    uint8_t Month; // 1-12
+    uint8_t Year; // Full year (e.g., 2024)
 } time_struct;
 extern time_struct TIME;
 
-
 typedef enum {
     RTC_RFM69_SET_TIME_SUCCESS = 1,
     RTC_RFM69_SET_TIME_FAILED = 2,
 } RTC_RFM69_STATUS;
 
-
 typedef enum // Goes into ID
 { DATA_SEND_SUCCESS = 1,
   DATA_NOT_SENT = 2 } DATA_SEND_STATUS;
-    
 
 typedef enum // Goes into ID
 { MSG_TYPE_STRING = 1,
@@ -101,13 +107,10 @@ typedef enum // Goes into flags
   MSG_SEND_COUNTS = 31,
   MSG_RECV_COUNTS_SUCCESS = 32,
   MSG_RECV_COUNTS_FAIL = 33,
-  MSG_RESENT_COUNTS = 34} MSG_REQUEST_TYPE_FLAG;
+  MSG_RESENT_COUNTS = 34 } MSG_REQUEST_TYPE_FLAG;
 
-  
-
-#ifdef	__cplusplus
+#ifdef __cplusplus
 }
 #endif
 
-#endif	/* DEFINES_H */
-
+#endif /* DEFINES_H */