CC3D / NAZE - Adding support for hardware controlled inverter for use by

SBUS RX.

Makefile

@@ -184,6 +184,7 @@ NAZE_SRC	 = startup_stm32f10x_md_gcc.S \
 		   drivers/bus_i2c_stm32f10x.c \
 		   drivers/compass_hmc5883l.c \
 		   drivers/gpio_stm32f10x.c \
+		   drivers/inverter.c \
 		   drivers/light_led_stm32f10x.c \
 		   drivers/light_ws2811strip.c \
 		   drivers/light_ws2811strip_stm32f10x.c \
@@ -252,6 +253,7 @@ CC3D_SRC	 = startup_stm32f10x_md_gcc.S \
 		   drivers/bus_i2c_stm32f10x.c \
 		   drivers/bus_spi.c \
 		   drivers/gpio_stm32f10x.c \
+		   drivers/inverter.c \
 		   drivers/light_led_stm32f10x.c \
 		   drivers/light_ws2811strip.c \
 		   drivers/light_ws2811strip_stm32f10x.c \

src/main/drivers/inverter.c

@@ -0,0 +1,43 @@
+/*
+ * 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 <stdbool.h>
+#include <stdint.h>
+
+#include "platform.h"
+
+#include "gpio.h"
+
+#include "inverter.h"
+
+void initInverter(void)
+{
+#ifdef INVERTER
+    struct {
+        GPIO_TypeDef *gpio;
+        gpio_config_t cfg;
+    } gpio_setup = {
+        .gpio = INVERTER_GPIO,
+        .cfg = { INVERTER_PIN, Mode_Out_OD, Speed_2MHz }
+    };
+
+    RCC_APB2PeriphClockCmd(INVERTER_PERIPHERAL, ENABLE);
+
+    gpioInit(gpio_setup.gpio, &gpio_setup.cfg);
+
+#endif
+}

src/main/drivers/inverter.h

@@ -0,0 +1,29 @@
+/*
+ * 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/>.
+ */
+
+#pragma once
+
+#ifdef INVERTER
+#define INVERTER_OFF digitalLo(INVERTER_GPIO, INVERTER_PIN);
+#define INVERTER_ON digitalHi(INVERTER_GPIO, INVERTER_PIN);
+#else
+#define INVERTER_OFF ;
+#define INVERTER_ON ;
+#endif
+
+void initInverter(void);
+

src/main/drivers/serial_uart.c

@@ -28,6 +28,9 @@
 
 #include "build_config.h"
 
+#include "gpio.h"
+#include "inverter.h"
+
 #include "serial.h"
 #include "serial_uart.h"
 
@@ -64,6 +67,13 @@ serialPort_t *uartOpen(USART_TypeDef *USARTx, serialReceiveCallbackPtr callback,
 
     uartPort_t *s = NULL;
 
+#ifdef INVERTER
+    if (inversion == SERIAL_INVERTED && USARTx == INVERTER_USART) {
+        // Enable hardware inverter if available.
+        INVERTER_ON;
+    }
+#endif
+
     if (USARTx == USART1) {
         s = serialUSART1(baudRate, mode);
     } else if (USARTx == USART2) {

src/main/drivers/system.c

@@ -24,6 +24,7 @@
 #include "gpio.h"
 #include "light_led.h"
 #include "sound_beeper.h"
+#include "inverter.h"
 #include "bus_i2c.h"
 #include "bus_spi.h"
 
@@ -112,6 +113,7 @@ void systemInit(bool overclock)
 
     ledInit();
     beeperInit();
+    initInverter();
 
     // Init cycle counter
     cycleCounterInit();

src/main/rx/sbus.c

@@ -25,6 +25,9 @@
 
 #include "drivers/system.h"
 
+#include "drivers/gpio.h"
+#include "drivers/inverter.h"
+
 #include "drivers/serial.h"
 #include "drivers/serial_uart.h"
 #include "io/serial.h"
@@ -57,7 +60,8 @@ void sbusUpdateSerialRxFunctionConstraint(functionConstraint_t *functionConstrai
 bool sbusInit(rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig, rcReadRawDataPtr *callback)
 {
     int b;
-    sBusPort = openSerialPort(FUNCTION_SERIAL_RX, sbusDataReceive, SBUS_BAUDRATE, (portMode_t)(MODE_RX | MODE_SBUS), SERIAL_NOT_INVERTED);
+
+    sBusPort = openSerialPort(FUNCTION_SERIAL_RX, sbusDataReceive, SBUS_BAUDRATE, (portMode_t)(MODE_RX | MODE_SBUS), SERIAL_INVERTED);
 
     for (b = 0; b < SBUS_MAX_CHANNEL; b++)
         sbusChannelData[b] = 2 * (rxConfig->midrc - SBUS_OFFSET);

src/main/target/CC3D/target.h

@@ -20,8 +20,14 @@
 #define LED0_PERIPHERAL RCC_APB2Periph_GPIOB
 #define LED0
 
+#define INVERTER_PIN Pin_2 // PB2 (BOOT1) used as inverter select GPIO
+#define INVERTER_GPIO GPIOB
+#define INVERTER_PERIPHERAL RCC_APB2Periph_GPIOB
+#define INVERTER_USART USART1
+
 #define ACC
 #define GYRO
+#define INVERTER
 
 // #define SOFT_I2C // enable to test software i2c
 // #define SOFT_I2C_PB1011 // If SOFT_I2C is enabled above, need to define pinout as well (I2C1 = PB67, I2C2 = PB1011)

src/main/target/NAZE/target.h

@@ -32,6 +32,11 @@
 #define BARO_GPIO   GPIOC
 #define BARO_PIN    Pin_13
 
+#define INVERTER_PIN Pin_2 // PB2 (BOOT1) abused as inverter select GPIO
+#define INVERTER_GPIO GPIOB
+#define INVERTER_PERIPHERAL RCC_APB2Periph_GPIOB
+#define INVERTER_USART USART2
+
 #define GYRO
 #define ACC
 #define MAG
@@ -40,6 +45,7 @@
 #define BEEPER
 #define LED0
 #define LED1
+#define INVERTER
 
 #define I2C_DEVICE (I2CDEV_2)