RF antenna bias voltage control API.

firmware/application/radio.cpp

@@ -152,7 +152,13 @@ void set_baseband_decimation_by(const size_t n) {
 	baseband_cpld.set_decimation_by(n);
 }
 
+void set_antenna_bias(const bool on) {
+	/* Pull MOSFET gate low to turn on antenna bias. */
+	first_if.set_gpo1(on ? 0 : 1);
+}
+
 void disable() {
+	set_antenna_bias(false);
 	baseband_codec.set_mode(max5864::Mode::Shutdown);
 	second_if.set_mode(max2837::Mode::Standby);
 	first_if.disable();

firmware/application/radio.hpp

@@ -42,6 +42,7 @@ void set_vga_gain(const int_fast8_t db);
 void set_sampling_frequency(const uint32_t frequency);
 void set_baseband_filter_bandwidth(const uint32_t bandwidth_minimum);
 void set_baseband_decimation_by(const size_t n);
+void set_antenna_bias(const bool on);
 
 void disable();
 

firmware/application/receiver_model.cpp

@@ -52,6 +52,15 @@ void ReceiverModel::set_reference_ppm_correction(int32_t v) {
 	clock_manager.set_reference_ppb(v * 1000);
 }
 
+bool ReceiverModel::antenna_bias() const {
+	return antenna_bias_;
+}
+
+void ReceiverModel::set_antenna_bias(bool enabled) {
+	antenna_bias_ = enabled;
+	update_antenna_bias();
+}
+
 bool ReceiverModel::rf_amp() const {
 	return rf_amp_;
 }
@@ -113,6 +122,7 @@ uint32_t ReceiverModel::baseband_oversampling() const {
 void ReceiverModel::enable() {
 	radio::set_direction(rf::Direction::Receive);
 	update_tuning_frequency();
+	update_antenna_bias();
 	update_rf_amp();
 	update_lna();
 	update_vga();
@@ -148,6 +158,10 @@ void ReceiverModel::update_tuning_frequency() {
 	radio::set_tuning_frequency(persistent_memory::tuned_frequency() + tuning_offset());
 }
 
+void ReceiverModel::update_antenna_bias() {
+	radio::set_antenna_bias(antenna_bias_);
+}
+
 void ReceiverModel::update_rf_amp() {
 	radio::set_rf_amp(rf_amp_);
 }

firmware/application/receiver_model.hpp

@@ -58,6 +58,9 @@ public:
 	int32_t reference_ppm_correction() const;
 	void set_reference_ppm_correction(int32_t v);
 
+	bool antenna_bias() const;
+	void set_antenna_bias(bool enabled);
+
 	bool rf_amp() const;
 	void set_rf_amp(bool enabled);
 
@@ -87,6 +90,7 @@ public:
 private:
 	rf::Frequency frequency_step_ { 25000 };
 	bool rf_amp_ { false };
+	bool antenna_bias_ { false };
 	int32_t lna_gain_db_ { 32 };
 	uint32_t baseband_bandwidth_ { max2837::filter::bandwidth_minimum };
 	int32_t vga_gain_db_ { 32 };
@@ -101,6 +105,7 @@ private:
 	int32_t tuning_offset();
 
 	void update_tuning_frequency();
+	void update_antenna_bias();
 	void update_rf_amp();
 	void update_lna();
 	void update_baseband_bandwidth();

firmware/application/rffc507x.cpp

@@ -262,6 +262,18 @@ void RFFC507x::set_frequency(const rf::Frequency lo_frequency) {
 	flush();
 }
 
+void RFFC507x::set_gpo1(const bool new_value) {
+	if( new_value ) {
+		_map.r.gpo.p2gpo |= 1;
+		_map.r.gpo.p1gpo |= 1;
+	} else {
+		_map.r.gpo.p2gpo &= ~1;
+		_map.r.gpo.p1gpo &= ~1;
+	}
+
+	flush_one(Register::GPO);
+}
+
 spi::reg_t RFFC507x::readback(const Readback readback) {
 	/* TODO: This clobbers the rest of the DEV_CTRL register
 	 * Time to implement bitfields for registers.

firmware/application/rffc507x.hpp

@@ -808,6 +808,7 @@ public:
 
 	void set_mixer_current(const uint8_t value);
 	void set_frequency(const rf::Frequency lo_frequency);
+	void set_gpo1(const bool new_value);
 	
 	reg_t read(const address_t reg_num);