allow controlling external XOR gate connected to PB2 (BOOT1) to invert USART2_RX signal on F1. Currently used by sbus driver.

src/board.h

@@ -1,3 +1,7 @@
+/*
+ * This file is part of baseflight
+ * Licensed under GPL V3 or modified DCL - see https://github.com/multiwii/baseflight/blob/master/README.md
+ */
 #pragma once
 
 // for roundf()
@@ -208,6 +212,8 @@ typedef struct baro_t {
 #define BEEP_PIN    Pin_12 // PA12 (Buzzer)
 #define BARO_GPIO   GPIOC
 #define BARO_PIN    Pin_13
+#define INV_PIN     Pin_2 // PB2 (BOOT1) abused as inverter select GPIO
+#define INV_GPIO    GPIOB
 
 #define GYRO
 #define ACC
@@ -255,6 +261,14 @@ typedef struct baro_t {
 #define BEEP_ON                  ;
 #endif
 
+#ifdef INV_GPIO
+#define INV_OFF                  digitalLo(INV_GPIO, INV_PIN);
+#define INV_ON                   digitalHi(INV_GPIO, INV_PIN);
+#else
+#define INV_OFF                 ;
+#define INV_ON                  ;
+#endif
+
 // #define SOFT_I2C                 // enable to test software i2c
 
 #include "utils.h"

src/cli.c

@@ -1,3 +1,8 @@
+/*
+ * This file is part of baseflight
+ * Licensed under GPL V3 or modified DCL - see https://github.com/multiwii/baseflight/blob/master/README.md
+ */
+
 #include "board.h"
 #include "mw.h"
 
@@ -131,6 +136,7 @@ const clivalue_t valueTable[] = {
     { "fixedwing_althold_dir", VAR_INT8, &mcfg.fixedwing_althold_dir, -1, 1 },
     { "reboot_character", VAR_UINT8, &mcfg.reboot_character, 48, 126 },
     { "serial_baudrate", VAR_UINT32, &mcfg.serial_baudrate, 1200, 115200 },
+    { "serial2_rx_inverted", VAR_UINT8, &mcfg.serial2_rx_inverted, 0, 1 },
     { "softserial_baudrate", VAR_UINT32, &mcfg.softserial_baudrate, 1200, 19200 },
     { "softserial_1_inverted", VAR_UINT8, &mcfg.softserial_1_inverted, 0, 1 },
     { "softserial_2_inverted", VAR_UINT8, &mcfg.softserial_2_inverted, 0, 1 },

src/config.c

@@ -1,3 +1,8 @@
+/*
+ * This file is part of baseflight
+ * Licensed under GPL V3 or modified DCL - see https://github.com/multiwii/baseflight/blob/master/README.md
+ */
+
 #include "board.h"
 #include "mw.h"
 #include <string.h>
@@ -13,7 +18,7 @@ master_t mcfg;  // master config struct with data independent from profiles
 config_t cfg;   // profile config struct
 const char rcChannelLetters[] = "AERT1234";
 
-static const uint8_t EEPROM_CONF_VERSION = 64;
+static const uint8_t EEPROM_CONF_VERSION = 65;
 static uint32_t enabledSensors = 0;
 static void resetConf(void);
 
@@ -125,7 +130,8 @@ void writeEEPROM(uint8_t b, uint8_t updateProfile)
     while (tries--) {
         FLASH_ClearFlag(FLASH_FLAG_EOP | FLASH_FLAG_PGERR | FLASH_FLAG_WRPRTERR);
 
-        status = FLASH_ErasePage(FLASH_WRITE_ADDR);
+        FLASH_ErasePage(FLASH_WRITE_ADDR);
+        status = FLASH_ErasePage(FLASH_WRITE_ADDR + FLASH_PAGE_SIZE);
         for (i = 0; i < sizeof(master_t) && status == FLASH_COMPLETE; i += 4)
             status = FLASH_ProgramWord(FLASH_WRITE_ADDR + i, *(uint32_t *)((char *)&mcfg + i));
         if (status == FLASH_COMPLETE)

src/drv_system.c

@@ -1,3 +1,8 @@
+/*
+ * This file is part of baseflight
+ * Licensed under GPL V3 or modified DCL - see https://github.com/multiwii/baseflight/blob/master/README.md
+ */
+
 #include "board.h"
 
 // cycles per microsecond
@@ -68,6 +73,10 @@ void systemInit(bool overclock)
             .cfg = { BEEP_PIN, Mode_Out_OD, Speed_2MHz }
         },
 #endif
+        {
+            .gpio = INV_GPIO,
+            .cfg = { INV_PIN, Mode_Out_PP, Speed_2MHz }
+        },
     };
     gpio_config_t gpio;
     uint32_t i;

src/mw.h

@@ -1,3 +1,8 @@
+/*
+ * This file is part of baseflight
+ * Licensed under GPL V3 or modified DCL - see https://github.com/multiwii/baseflight/blob/master/README.md
+ */
+
 #pragma once
 
 /* for VBAT monitoring frequency */
@@ -281,10 +286,11 @@ typedef struct master_t {
     int8_t gps_baudrate;                    // See GPSBaudRates enum.
 
     uint32_t serial_baudrate;
+    uint8_t serial2_rx_inverted;            // invert RX only for USART2 (for Sbus, etc)
 
-    uint32_t softserial_baudrate;             // shared by both soft serial ports
-    uint8_t softserial_1_inverted;            // use inverted softserial input and output signals on port 1
-    uint8_t softserial_2_inverted;            // use inverted softserial input and output signals on port 2
+    uint32_t softserial_baudrate;           // shared by both soft serial ports
+    uint8_t softserial_1_inverted;          // use inverted softserial input and output signals on port 1
+    uint8_t softserial_2_inverted;          // use inverted softserial input and output signals on port 2
 
     uint8_t telemetry_provider;             // See TelemetryProvider enum.
     uint8_t telemetry_port;                 // See TelemetryPort enum.

src/sbus.c

@@ -1,3 +1,8 @@
+/*
+ * This file is part of baseflight
+ * Licensed under GPL V3 or modified DCL - see https://github.com/multiwii/baseflight/blob/master/README.md
+ */
+
 #include "board.h"
 #include "mw.h"
 
@@ -22,6 +27,12 @@ void sbusInit(rcReadRawDataPtr *callback)
     int b;
     for (b = 0; b < SBUS_MAX_CHANNEL; b++)
         sbusChannelData[b] = 2 * (mcfg.midrc - SBUS_OFFSET);
+    // Configure hardware inverter on PB2. If not available, this has no effect.
+    if (mcfg.serial2_rx_inverted) {
+        INV_ON;
+    } else {
+        INV_OFF;
+    }
     core.rcvrport = uartOpen(USART2, sbusDataReceive, 100000, (portMode_t)(MODE_RX | MODE_SBUS));
     if (callback)
         *callback = sbusReadRawRC;