Make the two keyboard halves communicate with each other via I2C.

include/README.md

@@ -0,0 +1,3 @@
+# Include files
+
+These files are shared between multiple projects of this repository.

include/i2c.h

@@ -0,0 +1,6 @@
+#ifndef __I2C_H__
+#define __I2C_H__
+
+#define LEFT_KEYBOARD_HALF_I2C_ADDRESS_7BIT 8
+
+#endif

left/build/armgcc/CMakeLists.txt

@@ -19,7 +19,8 @@ SET(CMAKE_EXECUTABLE_LIBRARY_SUFFIX)
 
 # CURRENT DIRECTORY
 SET(SrcDir "${CMAKE_CURRENT_SOURCE_DIR}/../..")
-SET(KsdkDir "${SrcDir}/../lib/KSDK_1.3_FRDM-KL03Z/")
+SET(KsdkDir "${SrcDir}/../lib/KSDK_1.3_FRDM-KL03Z")
+SET(IncludeDir "${SrcDir}/../include")
 
 # DEBUG LINK FILE
 set(CMAKE_EXE_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG} -T${KsdkDir}/platform/devices/MKL03Z4/linker/gcc/MKL03Z32xxx4_flash.ld  -static")
@@ -75,6 +76,7 @@ IF(CMAKE_BUILD_TYPE MATCHES Debug)
     INCLUDE_DIRECTORIES(${KsdkDir}/examples)
     INCLUDE_DIRECTORIES(${KsdkDir}/examples/frdmkl03z)
     INCLUDE_DIRECTORIES(${KsdkDir})
+    INCLUDE_DIRECTORIES(${IncludeDir})
 ELSEIF(CMAKE_BUILD_TYPE MATCHES Release)
     INCLUDE_DIRECTORIES(${KsdkDir}/platform/osa/inc)
     INCLUDE_DIRECTORIES(${KsdkDir}/platform/utilities/inc)
@@ -89,6 +91,7 @@ ELSEIF(CMAKE_BUILD_TYPE MATCHES Release)
     INCLUDE_DIRECTORIES(${KsdkDir}/examples)
     INCLUDE_DIRECTORIES(${KsdkDir}/examples/frdmkl03z)
     INCLUDE_DIRECTORIES(${KsdkDir})
+    INCLUDE_DIRECTORIES(${IncludeDir})
 ENDIF()
 
 # ADD_EXECUTABLE

left/build/kds/.cproject

@@ -83,6 +83,7 @@
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_1.3_FRDM-KL03Z/examples"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_1.3_FRDM-KL03Z/examples/frdmkl03z"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_1.3_FRDM-KL03Z"/>
+									<listOptionValue builtIn="false" value="../../../../include"/>
 								</option>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.933718024" name="Language standard" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std" useByScannerDiscovery="true" value="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.gnu99" valueType="enumerated"/>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs.4702060583" name="Defined symbols (-D)" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs" useByScannerDiscovery="false" valueType="definedSymbols">
@@ -227,6 +228,7 @@
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_1.3_FRDM-KL03Z/examples"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_1.3_FRDM-KL03Z/examples/frdmkl03z"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_1.3_FRDM-KL03Z"/>
+									<listOptionValue builtIn="false" value="../../../../include"/>
 								</option>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.997197032" name="Language standard" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std" useByScannerDiscovery="true" value="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.gnu99" valueType="enumerated"/>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs.9999202301" name="Defined symbols (-D)" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs" useByScannerDiscovery="false" valueType="definedSymbols">

left/build/kds/.project

@@ -80,11 +80,21 @@
 			<type>1</type>
 			<locationURI>PARENT-3-PROJECT_LOC/lib/KSDK_1.3_FRDM-KL03Z/examples/frdmkl03z/pin_mux.h</locationURI>
 		</link>
+		<link>
+			<name>source/i2c.h</name>
+			<type>1</type>
+			<locationURI>PARENT-3-PROJECT_LOC/include/i2c.h</locationURI>
+		</link>
 		<link>
 			<name>source/main.c</name>
 			<type>1</type>
 			<locationURI>PARENT-2-PROJECT_LOC/main.c</locationURI>
 		</link>
+		<link>
+			<name>source/main.h</name>
+			<type>1</type>
+			<locationURI>PARENT-2-PROJECT_LOC/main.h</locationURI>
+		</link>
 		<link>
 			<name>startup/startup.c</name>
 			<type>1</type>

left/main.c

@@ -1,8 +1,52 @@
 #include "board.h"
 #include "fsl_clock_manager.h"
+#include "fsl_i2c_slave_driver.h"
+#include "fsl_i2c_shared_function.h"
+#include "i2c.h"
+#include "main.h"
+
+uint8_t isSw2Pressed;
+uint8_t isSw3Pressed;
+uint8_t buffer[I2C_DATA_LENGTH];
+
+void I2C0_IRQHandler(void)
+{
+    I2C_DRV_IRQHandler(I2C0_IDX);
+}
+
+static void i2c_slave_callback(uint8_t instance, i2c_slave_event_t i2cEvent, void *param)
+{
+    i2c_slave_state_t *slaveState = I2C_DRV_SlaveGetHandler(instance);
+
+    switch (i2cEvent) {
+        case kI2CSlaveTxReq:
+            slaveState->txSize = I2C_DATA_LENGTH;
+            slaveState ->txBuff = buffer;
+            slaveState ->isTxBusy = true;
+            buffer[0] = isSw2Pressed;
+            buffer[1] = isSw3Pressed;
+            break;
+
+        case kI2CSlaveTxEmpty:
+            slaveState->isTxBusy = false;
+            break;
+
+        default:
+            break;
+    }
+}
 
 int main(void)
 {
+    // Initialize clock.
+
+    CLOCK_SYS_EnablePortClock(PORTA_IDX);
+    CLOCK_SYS_EnablePortClock(PORTB_IDX);
+
+    BOARD_ClockInit();
+
+    // Initialize GPIO.
+
     gpio_input_pin_user_config_t inputPin[] =
     {
         {
@@ -43,16 +87,28 @@ int main(void)
         }
     };
 
-    CLOCK_SYS_EnablePortClock(PORTA_IDX);
-    CLOCK_SYS_EnablePortClock(PORTB_IDX);
-
-    BOARD_ClockInit();
-
     GPIO_DRV_Init(inputPin, outputPin);
 
+    // Initialize I2C.
+
+    i2c_slave_state_t slave;
+
+    i2c_slave_user_config_t userConfig = {
+        .address         = LEFT_KEYBOARD_HALF_I2C_ADDRESS_7BIT,
+        .slaveCallback   = i2c_slave_callback,
+        .callbackParam   = NULL,
+        .slaveListening  = true,
+        .startStopDetect = true,
+    };
+
+    configure_i2c_pins(0);
+    I2C_DRV_SlaveInit(BOARD_I2C_INSTANCE, &userConfig, &slave);
+
+    // Update switch states and toggle LEDs accordingly.
+
     while (1) {
-        uint8_t isSw2Pressed = GPIO_DRV_ReadPinInput(kGpioSW2);
+        isSw2Pressed = GPIO_DRV_ReadPinInput(kGpioSW2);
-        uint8_t isSw3Pressed = GPIO_DRV_ReadPinInput(kGpioSW3);
+        isSw3Pressed = GPIO_DRV_ReadPinInput(kGpioSW3);
         GPIO_DRV_WritePinOutput(kGpioLED1, isSw2Pressed);
         GPIO_DRV_WritePinOutput(kGpioLED3, isSw3Pressed);
     }

left/main.h

@@ -0,0 +1,6 @@
+#ifndef __MAIN_H__
+#define __MAIN_H__
+
+#define I2C_DATA_LENGTH 2
+
+#endif

right/build/armgcc/CMakeLists.txt

@@ -20,6 +20,7 @@ SET(CMAKE_EXECUTABLE_LIBRARY_SUFFIX)
 # CURRENT DIRECTORY
 SET(SrcDir "${CMAKE_CURRENT_SOURCE_DIR}/../..")
 SET(KsdkDir "${SrcDir}/../lib/KSDK_2.0_FRDM-K22F/")
+SET(IncludeDir "${SrcDir}/../include")
 
 SET(CMAKE_ASM_FLAGS_DEBUG "${CMAKE_ASM_FLAGS_DEBUG} -DDEBUG")
 SET(CMAKE_ASM_FLAGS_DEBUG "${CMAKE_ASM_FLAGS_DEBUG} -D__STARTUP_CLEAR_BSS")
@@ -149,11 +150,14 @@ include_directories(${KsdkDir}/CMSIS/Include)
 include_directories(${KsdkDir}/boards/frdmk22f)
 include_directories(${KsdkDir}/devices/MK22F51212/drivers)
 include_directories(${KsdkDir}/devices/MK22F51212)
+include_directories(${IncludeDir})
 
 add_executable(dev_composite_hid_mouse_hid_keyboard_bm.elf 
 "${KsdkDir}/devices/MK22F51212/gcc/startup_MK22F51212.S"
 "${KsdkDir}/middleware/usb_1.0.0/device/usb_device_khci.c"
 "${KsdkDir}/middleware/usb_1.0.0/device/usb_device_khci.h"
+"${KsdkDir}/devices/MK22F51212/drivers/fsl_i2c.h"
+"${KsdkDir}/devices/MK22F51212/drivers/fsl_i2c.c"
 "${KsdkDir}/devices/MK22F51212/drivers/fsl_lpuart.h"
 "${KsdkDir}/devices/MK22F51212/drivers/fsl_lpuart.c"
 "${KsdkDir}/devices/MK22F51212/drivers/fsl_uart.h"

right/build/kds/.cproject

@@ -81,6 +81,7 @@
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_2.0_FRDM-K22F/CMSIS/Include"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_2.0_FRDM-K22F/devices/MK22F51212/drivers"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_2.0_FRDM-K22F/devices/MK22F51212"/>
+									<listOptionValue builtIn="false" value="../../../../include"/>
 								</option>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.933718024" name="Language standard" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std" useByScannerDiscovery="true" value="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.gnu99" valueType="enumerated"/>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs.62587551" name="Defined symbols (-D)" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs" useByScannerDiscovery="false" valueType="definedSymbols">
@@ -220,6 +221,7 @@
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_2.0_FRDM-K22F/CMSIS/Include"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_2.0_FRDM-K22F/devices/MK22F51212/drivers"/>
 									<listOptionValue builtIn="false" value="../../../../lib/KSDK_2.0_FRDM-K22F/devices/MK22F51212"/>
+									<listOptionValue builtIn="false" value="../../../../include"/>
 								</option>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.997197032" name="Language standard" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std" useByScannerDiscovery="true" value="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.std.gnu99" valueType="enumerated"/>
 								<option id="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs.9752018572" name="Defined symbols (-D)" superClass="ilg.gnuarmeclipse.managedbuild.cross.option.c.compiler.defs" useByScannerDiscovery="false" valueType="definedSymbols">

right/build/kds/.project

@@ -125,6 +125,16 @@
 			<type>1</type>
 			<locationURI>$%7BPARENT-3-PROJECT_LOC%7D/lib/KSDK_2.0_FRDM-K22F/devices/MK22F51212/drivers/fsl_gpio.h</locationURI>
 		</link>
+		<link>
+			<name>drivers/fsl_i2c.c</name>
+			<type>1</type>
+			<locationURI>$%7BPARENT-3-PROJECT_LOC%7D/lib/KSDK_2.0_FRDM-K22F/devices/MK22F51212/drivers/fsl_i2c.c</locationURI>
+		</link>
+		<link>
+			<name>drivers/fsl_i2c.h</name>
+			<type>1</type>
+			<locationURI>$%7BPARENT-3-PROJECT_LOC%7D/lib/KSDK_2.0_FRDM-K22F/devices/MK22F51212/drivers/fsl_i2c.h</locationURI>
+		</link>
 		<link>
 			<name>drivers/fsl_lpuart.c</name>
 			<type>1</type>
@@ -180,11 +190,21 @@
 			<type>1</type>
 			<locationURI>$%7BPARENT-3-PROJECT_LOC%7D/lib/KSDK_2.0_FRDM-K22F/middleware/usb_1.0.0/osa/usb_osa_bm.h</locationURI>
 		</link>
+		<link>
+			<name>sources/i2c.h</name>
+			<type>1</type>
+			<locationURI>PARENT-3-PROJECT_LOC/include/i2c.h</locationURI>
+		</link>
 		<link>
 			<name>sources/main.c</name>
 			<type>1</type>
 			<locationURI>PARENT-2-PROJECT_LOC/main.c</locationURI>
 		</link>
+		<link>
+			<name>sources/main.h</name>
+			<type>1</type>
+			<locationURI>PARENT-2-PROJECT_LOC/main.h</locationURI>
+		</link>
 		<link>
 			<name>sources/usb_api.h</name>
 			<type>1</type>

right/include/board/pin_mux.c

@@ -34,8 +34,14 @@
 
 void BOARD_InitPins(void)
 {
+    // Ungate ports.
+    CLOCK_EnableClock(kCLOCK_PortA); // LEDs
+    CLOCK_EnableClock(kCLOCK_PortB); // SW3, I2C
+    CLOCK_EnableClock(kCLOCK_PortC); // SW2
+    CLOCK_EnableClock(kCLOCK_PortD); // LEDs
+    CLOCK_EnableClock(kCLOCK_PortE); // UART1 for OpenSDA
+
     // Set up UART1 for OpenSDA.
-    CLOCK_EnableClock(kCLOCK_PortE);
     PORT_SetPinMux(PORTE, 0u, kPORT_MuxAlt3);
     PORT_SetPinMux(PORTE, 1u, kPORT_MuxAlt3);
 
@@ -43,17 +49,12 @@ void BOARD_InitPins(void)
     port_pin_config_t switchConfig = {0};
     switchConfig.pullSelect = kPORT_PullUp;
     switchConfig.mux = kPORT_MuxAsGpio;
-    CLOCK_EnableClock(kCLOCK_PortC);
     PORT_SetPinConfig(BOARD_SW2_PORT, BOARD_SW2_GPIO_PIN, &switchConfig);
 
     // Set up SW3.
-    CLOCK_EnableClock(kCLOCK_PortB);
     PORT_SetPinConfig(BOARD_SW3_PORT, BOARD_SW3_GPIO_PIN, &switchConfig);
 
-    // Init LEDs.
+    // Initialize LEDs.
-
-    CLOCK_EnableClock(kCLOCK_PortA);
-    CLOCK_EnableClock(kCLOCK_PortD);
 
     PORT_SetPinMux(BOARD_LED_RED_GPIO_PORT, BOARD_LED_RED_GPIO_PIN, kPORT_MuxAsGpio);
     PORT_SetPinMux(BOARD_LED_GREEN_GPIO_PORT, BOARD_LED_GREEN_GPIO_PIN, kPORT_MuxAsGpio);
@@ -67,7 +68,19 @@ void BOARD_InitPins(void)
     GPIO_PinInit(BOARD_LED_GREEN_GPIO, BOARD_LED_GREEN_GPIO_PIN, &led_config);
     GPIO_PinInit(BOARD_LED_BLUE_GPIO, BOARD_LED_BLUE_GPIO_PIN, &led_config);
 
-    GPIO_SetPinsOutput(BOARD_LED_RED_GPIO, 1U << BOARD_LED_RED_GPIO_PIN);
+    GPIO_SetPinsOutput(BOARD_LED_RED_GPIO,   1 << BOARD_LED_RED_GPIO_PIN);
-    GPIO_SetPinsOutput(BOARD_LED_GREEN_GPIO, 1U << BOARD_LED_GREEN_GPIO_PIN);
+    GPIO_SetPinsOutput(BOARD_LED_GREEN_GPIO, 1 << BOARD_LED_GREEN_GPIO_PIN);
-    GPIO_SetPinsOutput(BOARD_LED_BLUE_GPIO, 1U << BOARD_LED_BLUE_GPIO_PIN);
+    GPIO_SetPinsOutput(BOARD_LED_BLUE_GPIO,  1 << BOARD_LED_BLUE_GPIO_PIN);
+
+    // Initialize I2C.
+
+    port_pin_config_t pinConfig = {0};
+    pinConfig.pullSelect = kPORT_PullUp;
+    pinConfig.openDrainEnable = kPORT_OpenDrainEnable;
+
+    PORT_SetPinConfig(PORTB, 2, &pinConfig);
+    PORT_SetPinConfig(PORTB, 3, &pinConfig);
+
+    PORT_SetPinMux(PORTB, 2, kPORT_MuxAlt2);
+    PORT_SetPinMux(PORTB, 3, kPORT_MuxAlt2);
 }

right/main.c

@@ -1,7 +1,9 @@
+#include "fsl_i2c.h"
 #include "include/board/clock_config.h"
 #include "include/board/board.h"
 #include "include/board/pin_mux.h"
 #include "usb_composite_device.h"
+#include "main.h"
 
 void main(void)
 {
@@ -9,8 +11,14 @@ void main(void)
     BOARD_BootClockHSRUN();
     BOARD_InitDebugConsole();
 
-    USB_DeviceApplicationInit();
+    i2c_master_config_t masterConfig;
+    uint32_t sourceClock;
+    I2C_MasterGetDefaultConfig(&masterConfig);
+    masterConfig.baudRate_Bps = I2C_BAUD_RATE;
+    sourceClock = CLOCK_GetFreq(I2C_MASTER_CLK_SRC);
+    I2C_MasterInit(EXAMPLE_I2C_MASTER_BASEADDR, &masterConfig, sourceClock);
 
-    while (1) {
+    InitUsb();
-    }
+
+    while (1);
 }

right/main.h

@@ -0,0 +1,9 @@
+#ifndef __MAIN_H__
+#define __MAIN_H__
+
+#define EXAMPLE_I2C_MASTER_BASEADDR I2C0
+#define I2C_BAUD_RATE 100000
+#define I2C_MASTER_CLK_SRC I2C0_CLK_SRC
+#define I2C_DATA_LENGTH 2
+
+#endif

right/usb_composite_device.c

@@ -96,7 +96,7 @@ void USB0_IRQHandler()
     USB_DeviceKhciIsrFunction(UsbCompositeDevice.deviceHandle);
 }
 
-void USB_DeviceApplicationInit()
+void InitUsb()
 {
     uint8_t usbDeviceKhciIrq[] = USB_IRQS;
     uint8_t irqNumber = usbDeviceKhciIrq[CONTROLLER_ID - kUSB_ControllerKhci0];

right/usb_composite_device.h

@@ -28,6 +28,6 @@
 
 //Functions:
 
-    extern void USB_DeviceApplicationInit();
+    extern void InitUsb();
 
 #endif

right/usb_interface_mouse.c

@@ -1,6 +1,9 @@
 #include "include/board/board.h"
 #include "usb_composite_device.h"
 #include "usb_interface_mouse.h"
+#include "fsl_i2c.h"
+#include "i2c.h"
+#include "main.h"
 
 static usb_device_endpoint_struct_t UsbMouseEndpoints[USB_MOUSE_ENDPOINT_COUNT] = {{
     USB_MOUSE_ENDPOINT_INDEX | (USB_IN << USB_DESCRIPTOR_ENDPOINT_ADDRESS_DIRECTION_SHIFT),
@@ -39,8 +42,19 @@ static usb_mouse_report_t UsbMouseReport;
 static uint8_t scrollCounter = 0;
 static volatile usb_status_t UsbMouseAction(void)
 {
+    uint8_t i2cBuffer[I2C_DATA_LENGTH];
+    i2c_master_transfer_t masterXfer;
+    masterXfer.slaveAddress = LEFT_KEYBOARD_HALF_I2C_ADDRESS_7BIT;
+    masterXfer.direction = kI2C_Read;
+    masterXfer.subaddress = 0;
+    masterXfer.subaddressSize = 0;
+    masterXfer.data = i2cBuffer;
+    masterXfer.dataSize = I2C_DATA_LENGTH;
+    masterXfer.flags = kI2C_TransferDefaultFlag;
+    I2C_MasterTransferBlocking(EXAMPLE_I2C_MASTER_BASEADDR, &masterXfer);
+
     UsbMouseReport.buttons = 0;
-    UsbMouseReport.x = 0;
+    UsbMouseReport.x = i2cBuffer[1] - i2cBuffer[0];
     UsbMouseReport.y = 0;
     UsbMouseReport.wheelX = 0;
     UsbMouseReport.wheelY = 0;