Add "Auto" mode to FrequencyField (#959)

* Add "Auto" mode to FrequencyField
* Use exponential function instead of hyperbolic
* Fix tabs
* Back to hyperbolic, better feel

.gitignore

@@ -13,6 +13,7 @@
 /sdcard/FREQMAN/BHT*
 /sdcard/FREQMAN/R.TXT
 /sdcard/FREQMAN/XXX.TXT
+/armbin
 
 # Compiled Object files
 *.slo

firmware/application/apps/ui_sd_over_usb.hpp

@@ -40,7 +40,7 @@ public:
 
 	void focus() override;
 
-	std::string title() const override { return "Flash Utility"; };	
+	std::string title() const override { return "SD over USB"; };	
 
 private:
 	NavigationView& nav_;

firmware/application/ui/ui_receiver.cpp

@@ -87,7 +87,22 @@ bool FrequencyField::on_key(const ui::KeyEvent event) {
 }
 
 bool FrequencyField::on_encoder(const EncoderEvent delta) {
+	if (step == 0) { // 'Auto' mode.'
+		auto ms = RTT2MS(halGetCounterValue());
+		auto delta_ms = last_ms_ <= ms ? ms - last_ms_ : ms;
+		last_ms_ = ms;
+
+		// The goal is to map 'scale' to a range of about 10 to 10M.
+		// The faster the encoder is rotated, the larger the step.
+		// Linear doesn't feel right. Hyperbolic felt better.
+		// To get these magic numbers, I graphed the function until the
+		// curve shape seemed about right then tested on device.
+		delta_ms = std::min(145ull, delta_ms) + 5; // Prevent DIV/0
+		int64_t scale = 200'000'000 / (0.001'55 * pow(delta_ms, 5.45)) + 8;
+		set_value(value() + (delta * scale));
+	} else {
 		set_value(value() + (delta * step));
+	}
 	return true;
 }
 

firmware/application/ui/ui_receiver.hpp

@@ -63,6 +63,7 @@ private:
 	const range_t range;
 	rf::Frequency value_ { 0 };
 	rf::Frequency step { 25000 };
+	uint64_t last_ms_ { 0 };
 
 	rf::Frequency clamp_value(rf::Frequency value);
 };
@@ -247,6 +248,7 @@ public:
 			parent_pos,
 			5,
 			{
+				{ " Auto",        0 },  /* Faster == larger step. */
 				{ "   10",       10 },  /* Fine tuning SSB voice pitch,in HF and QO-100 sat #669 */
 				{ "   50",       50 },	/* added 50Hz/10Hz,but we do not increase GUI digit decimal */
 				{ "  100",      100 },