Firmware revision 10 (patch 3)

Make millisecond delay atomic to avoid missed ticks

src/common.h

@@ -110,7 +110,6 @@ extern const Cfg cfgdata;
 extern Cfg cfg;
 extern int throt, ertm, erpm, temp, volt, curr, csum, dshotval, beepval;
 extern char analog, telreq, telmode, flipdir, beacon, dshotext;
-extern volatile uint32_t tickms;
 
 void init(void);
 void initio(void);
@@ -124,6 +123,7 @@ void io_serial(void);
 void io_analog(void);
 void adctrig(void);
 void adcdata(int t, int v, int c, int x);
+void delay(int ms);
 void kisstelem(void);
 void autotelem(void);
 int execcmd(char *buf);

src/main.c

@@ -66,10 +66,11 @@ Cfg cfg = cfgdata;
 
 int throt, ertm, erpm, temp, volt, curr, csum, dshotval, beepval = -1;
 char analog, telreq, telmode, flipdir, beacon, dshotext;
-volatile uint32_t tickms;
 
 static int step, sine, sync, ival, tval;
 static char prep, accl, tick, reverse, ready, brushed;
+static uint32_t tickms, tickmsv;
+static volatile char tickmsf;
 
 static void reset(void) {
 	__disable_irq();
@@ -465,7 +466,15 @@ void sys_tick_handler(void) {
 	SCB_ICSR = SCB_ICSR_PENDSVSET; // Continue with low priority
 	SCB_SCR = 0; // Resume main loop
 	if (++tick & 15) return; // 16kHz -> 1kHz
-	++tickms;
+	if (++tickms == tickmsv) tickmsf = 0;
+}
+
+void delay(int ms) {
+	__disable_irq();
+	tickmsv = tickms + ms;
+	tickmsf = 1;
+	__enable_irq();
+	while (tickmsf) TIM_EGR(GPTIM) = TIM_EGR_UG; // Reset arming timeout
 }
 
 void pend_sv_handler(void) {

src/util.c

@@ -298,8 +298,7 @@ int playmusic(const char *str, int vol) {
 			if (a < 1 || a > 99) break; // Sanity check
 			str = end;
 		}
-		uint32_t t = tickms + tmp * a;
-		while (t != tickms) TIM_EGR(GPTIM) = TIM_EGR_UG; // Reset arming timeout
+		delay(tmp * a);
 		TIM1_CCR2 = 0; // Preload silence
 	}
 #ifdef PWM_ENABLE