From a8ab17013f69217dcd6d2e15ffd9e21b28a0f4b7 Mon Sep 17 00:00:00 2001
From: cnlohr <lohr85@gmail.com>
Date: Tue, 25 Jun 2024 03:14:43 -0700
Subject: [PATCH] Switch to FM transmitter sweep

---
 ch32v/ch32v003-timer/nonlora.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/ch32v/ch32v003-timer/nonlora.c b/ch32v/ch32v003-timer/nonlora.c
index c6632b9..dc9b82a 100644
--- a/ch32v/ch32v003-timer/nonlora.c
+++ b/ch32v/ch32v003-timer/nonlora.c
@@ -48,7 +48,7 @@ SOFTWARE.
 // NOT LORA!!!
 
 // Transmit a sweep on 97.7MHz
-//#define FM_TRANSMITTER_SWEEP
+#define FM_TRANSMITTER_SWEEP
 
 // Nothing = Transmit a 315MHz signal.
 
@@ -376,7 +376,9 @@ void LoopFunction2()
 		{
 #ifdef FM_TRANSMITTER_SWEEP
 			// 97.7MHz FM Station
-			uint32_t cp = ((SysTick->CNT>>3)&0x3fff)+0x12900;
+			int notein = (SysTick->CNT>>4)&0x3fff;
+			if( notein > 0x1fff ) notein = 0x4000-notein;
+			uint32_t cp = (notein)+0x12900;
 #else
 			// 315MHz
 			uint32_t cp = 0x1bfc3;