PCF8574 Basic Driver

make/source.mk

@@ -45,6 +45,7 @@ COMMON_SRC = \
             drivers/exti.c \
             drivers/io.c \
             drivers/io_pca9685.c \
+            drivers/io_pcf8574.c \
             drivers/irlock.c \
             drivers/light_led.c \
             drivers/osd.c \

src/main/build/debug.h

@@ -73,5 +73,6 @@ typedef enum {
     DEBUG_IRLOCK,
     DEBUG_CD,
     DEBUG_KALMAN,
+    DEBUG_PCF8574,
     DEBUG_COUNT
 } debugType_e;

src/main/drivers/bus.h

@@ -145,6 +145,7 @@ typedef enum {
     DEVHW_UG2864,       // I2C OLED display
     DEVHW_SDCARD,       // Generic SD-Card
     DEVHW_IRLOCK,       // IR-Lock visual positioning hardware
+    DEVHW_PCF8574,      // 8-bit I/O expander
 } devHardwareType_e;
 
 typedef enum {

src/main/drivers/io_pcf8574.c

@@ -0,0 +1,90 @@
+/*
+ * This file is part of INAV.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Alternatively, the contents of this file may be used under the terms
+ * of the GNU General Public License Version 3, as described below:
+ *
+ * This file is free software: you may copy, redistribute 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.
+ *
+ * This file 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 this program. If not, see http://www.gnu.org/licenses/.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "drivers/bus.h"
+#include "drivers/io_pcf8574.h"
+#include "drivers/time.h"
+#include "build/debug.h"
+
+#ifdef USE_PCF8574
+
+#define PCF8574_WRITE_ADDRESS 0x40
+#define PCF8574_READ_ADDRESS 0x41
+
+static busDevice_t *busDev;
+
+static bool deviceDetect(busDevice_t *busDev)
+{
+    for (int retry = 0; retry < 5; retry++)
+    {
+        uint8_t sig;
+
+        delay(150);
+
+        bool ack = busRead(busDev, 0x00, &sig);
+        if (ack)
+        {
+            return true;
+        }
+    };
+
+    return false;
+}
+
+bool pcf8574Init(void)
+{
+    busDev = busDeviceInit(BUSTYPE_I2C, DEVHW_PCF8574, 0, 0);
+    if (busDev == NULL)
+    {
+        DEBUG_SET(DEBUG_PCF8574, 0, 1);
+        return false;
+    }
+
+    if (!deviceDetect(busDev))
+    {
+        DEBUG_SET(DEBUG_PCF8574, 0, 2);
+        busDeviceDeInit(busDev);
+        return false;
+    }
+
+    pcf8574Write(0x00); //Set all ports to OFF
+    delay(25);
+    return true;
+}
+
+void pcf8574Write(uint8_t data)
+{
+    busWrite(busDev, PCF8574_WRITE_ADDRESS, data);
+}
+
+uint8_t pcf8574Read(void)
+{
+    uint8_t data;
+    busRead(busDev, PCF8574_READ_ADDRESS, &data);
+    return data;
+}
+
+#endif

src/main/drivers/io_pcf8574.h

@@ -0,0 +1,29 @@
+/*
+ * This file is part of INAV.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Alternatively, the contents of this file may be used under the terms
+ * of the GNU General Public License Version 3, as described below:
+ *
+ * This file is free software: you may copy, redistribute 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.
+ *
+ * This file 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 this program. If not, see http://www.gnu.org/licenses/.
+ */
+
+#pragma once
+
+bool pcf8574Init(void);
+void pcf8574Write(uint8_t data);
+uint8_t pcf8574Read(void);

src/main/fc/fc_init.c

@@ -83,6 +83,7 @@
 #include "msc/emfat_file.h"
 #endif
 #include "drivers/sdcard/sdcard.h"
+#include "drivers/io_pcf8574.h"
 
 #include "fc/cli.h"
 #include "fc/config.h"
@@ -674,6 +675,11 @@ void init(void)
     }
 #endif
 
+#ifdef USE_PCF8574
+    bool pcfActive = pcf8574Init();
+    DEBUG_SET(DEBUG_PCF8574, 1, pcfActive);
+#endif
+
     // Considering that the persistent reset reason is only used during init
     persistentObjectWrite(PERSISTENT_OBJECT_RESET_REASON, RESET_NONE);
 

src/main/fc/settings.yaml

@@ -84,7 +84,7 @@ tables:
       "FLOW", "SBUS", "FPORT", "ALWAYS", "SAG_COMP_VOLTAGE",
       "VIBE", "CRUISE", "REM_FLIGHT_TIME", "SMARTAUDIO", "ACC", "ITERM_RELAX",
       "ERPM", "RPM_FILTER", "RPM_FREQ", "NAV_YAW", "DYNAMIC_FILTER", "DYNAMIC_FILTER_FREQUENCY",
-      "IRLOCK", "CD", "KALMAN"]
+      "IRLOCK", "CD", "KALMAN", "PCF8574"]
   - name: async_mode
     values: ["NONE", "GYRO", "ALL"]
   - name: aux_operator

src/main/target/common.h

@@ -121,6 +121,9 @@
 #define USE_D_BOOST
 #define USE_ANTIGRAVITY
 
+#define USE_I2C_IO_EXPANDER
+#define USE_PCF8574
+
 #else // FLASH_SIZE < 256
 #define LOG_LEVEL_MAXIMUM LOG_LEVEL_ERROR
 #endif

src/main/target/common_hardware.c

@@ -353,4 +353,21 @@
     BUSDEV_REGISTER_I2C(busdev_irlock,      DEVHW_IRLOCK,       IRLOCK_I2C_BUS,     0x54,               NONE,           DEVFLAGS_USE_RAW_REGISTERS);
 #endif
 
+#if defined(USE_I2C) && defined(USE_PCF8574)
+
+    #if !defined(PCF8574_I2C_BUS) && defined(EXTERNAL_I2C_BUS)
+        #define PCF8574_I2C_BUS EXTERNAL_I2C_BUS
+    #endif
+
+    #if !defined(PCF8574_I2C_BUS) && defined(DEFAULT_I2C_BUS)
+        #define PCF8574_I2C_BUS DEFAULT_I2C_BUS
+    #endif
+
+    #if !defined(PCF8574_I2C_BUS)
+        #define PCF8574_I2C_BUS BUS_I2C1
+    #endif
+
+    BUSDEV_REGISTER_I2C(busdev_pcf8574,      DEVHW_PCF8574,       PCF8574_I2C_BUS,     0x20,               NONE,           DEVFLAGS_NONE, 0);
+#endif
+
 #endif  // USE_TARGET_HARDWARE_DESCRIPTORS