Increase STM32 emulated EEPROM commit delay (ExpressLRS#1143)

CapnBry · web-flow · commit 98ccefd86ece · 2021-12-02T06:26:07.000+10:00
* Extend commit pause by one more cycle

-- At the current rate because that's the rate the
timer is running at, not the new rate.
-- ChangeRadioParams after commit since it changes the Radio.freq

* Correct 50Hz 25Hz time on air to be accurate
diff --git a/src/src/common.cpp b/src/src/common.cpp
@@ -14,8 +14,8 @@ expresslrs_mod_settings_s ExpressLRS_AirRateConfig[RATE_MAX] = {
 expresslrs_rf_pref_params_s ExpressLRS_AirRateRFperf[RATE_MAX] = {
     {0, RATE_200HZ, -112, 4380, 3000, 2500, 600, 5000},
     {1, RATE_100HZ, -117, 8770, 3500, 2500, 600, 5000},
-    {2, RATE_50HZ, -120, 17540, 4000, 2500, 600, 5000},
-    {3, RATE_25HZ, -123, 17540, 6000, 4000, 0, 5000}};
+    {2, RATE_50HZ, -120, 18560, 4000, 2500, 600, 5000},
+    {3, RATE_25HZ, -123, 29950, 6000, 4000, 0, 5000}};
 #endif
 
 #if defined(Regulatory_Domain_ISM_2400)
diff --git a/src/src/tx_main.cpp b/src/src/tx_main.cpp
@@ -549,12 +549,11 @@ void ICACHE_RAM_ATTR ModelUpdateReq()
 
 static void ConfigChangeCommit()
 {
-  ChangeRadioParams();
-
-  // Write the uncommitted eeprom values
+  // Write the uncommitted eeprom values (may block for a while)
   config.Commit();
-  // Resume the timer, will take one hop for the radio to be on the right frequency
-  // if we missed a hop
+  // Change params after the blocking finishes as a rate change will change the radio freq
+  ChangeRadioParams();
+  // Resume the timer, will take one hop for the radio to be on the right frequency if we missed a hop
   hwTimer.callbackTock = &timerCallbackNormal;
   devicesTriggerEvent();
 }
@@ -575,10 +574,11 @@ static void CheckConfigChangePending()
     // The code expects to enter here shortly after the tock ISR has started sending the last
     // sync packet, before the tick ISR. Because the EEPROM write takes so long and disables
     // interrupts, FastForward the timer
-    const uint32_t EEPROM_WRITE_DURATION = 30000; // us, ~27ms is where it starts getting off by one
-    const uint32_t cycleInterval = get_elrs_airRateConfig(config.GetRate())->interval;
+    const uint32_t EEPROM_WRITE_DURATION = 30000; // us, a page write on F103C8 takes ~29.3ms
+    const uint32_t cycleInterval = ExpressLRS_currAirRate_Modparams->interval;
     // Total time needs to be at least DURATION, rounded up to next cycle
-    uint32_t pauseCycles = (EEPROM_WRITE_DURATION + cycleInterval - 1) / cycleInterval;
+    // adding one cycle that will be eaten by busywaiting for the transmit to end
+    uint32_t pauseCycles = ((EEPROM_WRITE_DURATION + cycleInterval - 1) / cycleInterval) + 1;
     // Pause won't return until paused, and has just passed the tick ISR (but not fired)
     hwTimer.pause(pauseCycles * cycleInterval);
 
