Fix handling of uninitialised EEPROM values

PWM channels now set to 0, CC channel to 30mA, dt to 1000us

src/modules/illumination/illumination.cpp

@@ -125,14 +125,27 @@ void illumination_setup()
     #ifdef WIRING_CC_LED
         EEPROM.get(cc_value_eeprom, cc_value);
         pinMode(WIRING_CC_LED, OUTPUT);
+        if (cc_value > 32.0)
+        {
+            //default value ~30mA
+            cc_value = 10;
+            EEPROM.put(cc_value_eeprom, cc_value);
+        }
+
         if (cc_value > 0)
             cc_set_value(cc_value/32.0);
     #endif
 
+    bool frequency_valid = false;
     #ifdef MCU_PICO
+        frequency_valid = true;
         EEPROM.get(pwm_frequency_eeprom, pwm_frequency);
-        if (pwm_frequency < 1)
+        if (pwm_frequency < 1 || pwm_frequency > 2000000)
+        {
+            frequency_valid = false;
             pwm_frequency = 64000;
+            EEPROM.put(pwm_frequency_eeprom, pwm_frequency);
+        }
         analogWriteRange(65535);
         analogWriteFreq(pwm_frequency);//32khz seems sensible
     #endif
@@ -140,6 +153,14 @@ void illumination_setup()
     for(int i = 0; i < PWM_NUM; i++)
     {
         EEPROM.get(pwm_values_eeprom+i*sizeof(uint16_t), pwm_values[i]);
+        //rp2040 has 16bit PWM range so we rely on frequency to check if this
+        //is the first start. On other platforms this value is enough
+        if (pwm_values[i] == 65535 && !frequency_valid)
+        {
+            pwm_values[i] = 0;
+            EEPROM.put(pwm_values_eeprom+i*sizeof(uint16_t), pwm_values[i]);
+        }
+
         if (pwm_values[i] > 0)
             analogWrite(pwm_led_pins[i], pwm_values[i]);
     }

src/modules/stage/stage.cpp

@@ -54,7 +54,7 @@ void stage_setup()
     }
 
     EEPROM.get(min_step_delay_eeprom, min_step_delay);
-    if (min_step_delay < 0)
+    if (min_step_delay <= 0)
     { // -1 seems to be what we get if it's uninitialised.
         min_step_delay = 1000;
         EEPROM.put(min_step_delay_eeprom, min_step_delay);