Add the first unit test for the mixer.

See #16

src/main/drivers/pwm_mapping.c

@@ -28,6 +28,12 @@
 #include "pwm_output.h"
 #include "pwm_rx.h"
 #include "pwm_mapping.h"
+
+void pwmBrushedMotorConfig(const timerHardware_t *timerHardware, uint8_t motorIndex, uint16_t motorPwmRate, uint16_t idlePulse);
+void pwmBrushlessMotorConfig(const timerHardware_t *timerHardware, uint8_t motorIndex, uint16_t motorPwmRate, uint16_t idlePulse);
+void pwmOneshotMotorConfig(const timerHardware_t *timerHardware, uint8_t motorIndex, uint16_t idlePulse);
+void pwmServoConfig(const timerHardware_t *timerHardware, uint8_t servoIndex, uint16_t servoPwmRate, uint16_t servoCenterPulse);
+
 /*
     Configuration maps
 

src/main/drivers/pwm_output.h

@@ -17,12 +17,7 @@
 
 #pragma once
 
-void pwmBrushedMotorConfig(const timerHardware_t *timerHardware, uint8_t motorIndex, uint16_t motorPwmRate, uint16_t idlePulse);
-void pwmBrushlessMotorConfig(const timerHardware_t *timerHardware, uint8_t motorIndex, uint16_t motorPwmRate, uint16_t idlePulse);
-void pwmOneshotMotorConfig(const timerHardware_t *timerHardware, uint8_t motorIndex, uint16_t idlePulse);
-
 void pwmWriteMotor(uint8_t index, uint16_t value);
 void pwmCompleteOneshotMotorUpdate(uint8_t motorCount);
 
-void pwmServoConfig(const timerHardware_t *timerHardware, uint8_t servoIndex, uint16_t servoPwmRate, uint16_t servoCenterPulse);
 void pwmWriteServo(uint8_t index, uint16_t value);

src/main/flight/mixer.c

@@ -27,8 +27,6 @@
 #include "common/maths.h"
 
 #include "drivers/system.h"
-#include "drivers/gpio.h"
-#include "drivers/timer.h"
 #include "drivers/pwm_output.h"
 #include "drivers/pwm_mapping.h"
 #include "drivers/sensor.h"
@@ -78,7 +76,7 @@ static mixerMode_e currentMixerMode;
 static gimbalConfig_t *gimbalConfig;
 int16_t servo[MAX_SUPPORTED_SERVOS];
 static int useServo;
-static uint8_t servoCount;
+STATIC_UNIT_TESTED uint8_t servoCount;
 static servoParam_t *servoConf;
 static lowpass_t lowpassFilters[MAX_SUPPORTED_SERVOS];
 #endif
@@ -404,6 +402,25 @@ void mixerResetMotors(void)
 }
 
 #ifdef USE_SERVOS
+
+STATIC_UNIT_TESTED void forwardAuxChannelsToServos(void)
+{
+    // offset servos based off number already used in mixer types
+    // airplane and servo_tilt together can't be used
+    int8_t firstServo = servoCount - AUX_FORWARD_CHANNEL_TO_SERVO_COUNT;
+
+    // start forwarding from this channel
+    uint8_t channelOffset = AUX1;
+
+    int8_t servoOffset;
+    for (servoOffset = 0; servoOffset < AUX_FORWARD_CHANNEL_TO_SERVO_COUNT; servoOffset++) {
+        if (firstServo + servoOffset < 0) {
+            continue; // there are not enough servos to forward all the AUX channels.
+        }
+        pwmWriteServo(firstServo + servoOffset, rcData[channelOffset++]);
+    }
+}
+
 static void updateGimbalServos(void)
 {
     pwmWriteServo(0, servo[0]);
@@ -653,20 +670,7 @@ void mixTable(void)
 
     // forward AUX1-4 to servo outputs (not constrained)
     if (gimbalConfig->gimbal_flags & GIMBAL_FORWARDAUX) {
-        // offset servos based off number already used in mixer types
-        // airplane and servo_tilt together can't be used
-        int8_t firstServo = servoCount - AUX_FORWARD_CHANNEL_TO_SERVO_COUNT;
-
-        // start forwarding from this channel
-        uint8_t channelOffset = AUX1;
-
-        int8_t servoOffset;
-        for (servoOffset = 0; servoOffset < AUX_FORWARD_CHANNEL_TO_SERVO_COUNT; servoOffset++) {
-            if (firstServo + servoOffset < 0) {
-                continue; // there are not enough servos to forward all the AUX channels.
-            }
-            pwmWriteServo(firstServo + servoOffset, rcData[channelOffset++]);
-        }
+        forwardAuxChannelsToServos();
     }
 #endif
 

src/test/Makefile

@@ -46,6 +46,7 @@ CXX_FLAGS = $(COMMON_FLAGS) \
 TESTS = \
 	battery_unittest \
 	flight_imu_unittest \
+	flight_mixer_unittest \
 	altitude_hold_unittest \
 	maths_unittest \
 	gps_conversion_unittest \
@@ -364,6 +365,30 @@ lowpass_unittest : \
 
 	$(CXX) $(CXX_FLAGS) -lpthread $^ -o $(OBJECT_DIR)/$@
 
+$(OBJECT_DIR)/flight/mixer.o : \
+	$(USER_DIR)/flight/mixer.c \
+	$(USER_DIR)/flight/mixer.h \
+	$(GTEST_HEADERS)
+
+	@mkdir -p $(dir $@)
+	$(CC) $(C_FLAGS) $(TEST_CFLAGS) -c $(USER_DIR)/flight/mixer.c -o $@
+
+$(OBJECT_DIR)/flight_mixer_unittest.o : \
+	$(TEST_DIR)/flight_mixer_unittest.cc \
+	$(USER_DIR)/flight/mixer.h \
+	$(GTEST_HEADERS)
+
+	@mkdir -p $(dir $@)
+	$(CXX) $(CXX_FLAGS) $(TEST_CFLAGS) -c $(TEST_DIR)/flight_mixer_unittest.cc -o $@
+
+flight_mixer_unittest : \
+	$(OBJECT_DIR)/flight/mixer.o \
+	$(OBJECT_DIR)/flight_mixer_unittest.o \
+	$(OBJECT_DIR)/common/maths.o \
+	$(OBJECT_DIR)/gtest_main.a
+
+	$(CXX) $(CXX_FLAGS) -lpthread $^ -o $(OBJECT_DIR)/$@
+
 
 test: $(TESTS)
 	set -e && for test in $(TESTS) ; do \

src/test/unit/flight_mixer_unittest.cc

@@ -0,0 +1,125 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Cleanflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <limits.h>
+
+extern "C" {
+    #include "platform.h"
+
+    #include "common/axis.h"
+    #include "common/maths.h"
+
+    #include "drivers/sensor.h"
+    #include "drivers/accgyro.h"
+
+    #include "sensors/sensors.h"
+    #include "sensors/acceleration.h"
+
+    #include "rx/rx.h"
+    #include "flight/pid.h"
+    #include "flight/imu.h"
+    #include "flight/mixer.h"
+    #include "flight/lowpass.h"
+
+    #include "io/rc_controls.h"
+
+    extern uint8_t servoCount;
+    void forwardAuxChannelsToServos(void);
+
+}
+
+#include "unittest_macros.h"
+#include "gtest/gtest.h"
+
+typedef struct motor_s {
+    uint16_t value;
+} motor_t;
+
+typedef struct servo_s {
+    uint16_t value;
+} servo_t;
+
+motor_t motors[MAX_SUPPORTED_MOTORS];
+servo_t servos[MAX_SUPPORTED_SERVOS];
+
+uint8_t lastOneShotUpdateMotorCount;
+
+
+TEST(FlightMixerTest, TestForwardAuxChannelsToServosWithNoServos)
+{
+    // given
+    memset(&motors, 0, sizeof(motors));
+    memset(&servos, 0, sizeof(servos));
+    servoCount = 0;
+
+    rcData[AUX1] = 1500;
+    rcData[AUX2] = 1500;
+    rcData[AUX3] = 1500;
+    rcData[AUX4] = 1500;
+
+    // when
+    forwardAuxChannelsToServos();
+
+    // then
+    for (uint8_t i = 0; i < MAX_SUPPORTED_SERVOS; i++) {
+        EXPECT_EQ(servos[i].value, 0);
+    }
+}
+
+// STUBS
+
+extern "C" {
+rollAndPitchInclination_t inclination;
+rxRuntimeConfig_t rxRuntimeConfig;
+
+int16_t axisPID[XYZ_AXIS_COUNT];
+int16_t rcCommand[4];
+int16_t rcData[MAX_SUPPORTED_RC_CHANNEL_COUNT];
+
+uint32_t rcModeActivationMask;
+int16_t debug[4];
+
+uint8_t stateFlags;
+uint16_t flightModeFlags;
+uint8_t armingFlags;
+
+void delay(uint32_t) {}
+
+bool feature(uint32_t) {
+    return true;
+}
+
+int32_t lowpassFixed(lowpass_t *, int32_t, int16_t) {
+    return 0;
+}
+
+void pwmWriteMotor(uint8_t index, uint16_t value) {
+    motors[index].value = value;
+}
+
+void pwmCompleteOneshotMotorUpdate(uint8_t motorCount) {
+    lastOneShotUpdateMotorCount = motorCount;
+}
+
+void pwmWriteServo(uint8_t index, uint16_t value) {
+    servos[index].value = value;
+}
+
+}