add serial communication snippets (#108)

* add serial snippets

* add debug printf snippets

Author: Qinghao Shi

APIs_Platform/Callback_SerialPassthrough/main.cpp

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+static UnbufferedSerial pc(USBTX, USBRX);
+static UnbufferedSerial uart(D1, D0);
+DigitalOut led1(LED1);
+DigitalOut led4(LED4);
+char *pc2uart = new char[1];
+char *uart2pc = new char[1];
+
+void uart_recv()
+{
+    led1 = !led1;
+    while (uart.readable()) {
+        uart.read(uart2pc, sizeof(uart2pc));
+        pc.write(uart2pc, sizeof(uart2pc));
+    }
+}
+
+void pc_recv()
+{
+    while (pc.readable()) {
+        led4 = !led4;
+        pc.read(pc2uart, sizeof(pc2uart));
+        uart.write(pc2uart, sizeof(pc2uart));
+    }
+}
+
+int main()
+{
+    pc.attach(&pc_recv, UnbufferedSerial::RxIrq);
+    uart.attach(&uart_recv, UnbufferedSerial::RxIrq);
+
+    while (1) {
+        sleep();
+    }
+}

APIs_Platform/PlatfromOverview_Callbacks/main.cpp

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+// Create a serial object
+static UnbufferedSerial serial(USBTX, USBRX);
+char *c = new char[1];
+
+// A function that echoes any received data back
+void echo()
+{
+    while (serial.readable()) {
+        serial.read(c, sizeof(c));
+        serial.write(c, sizeof(c));
+    }
+}
+
+int main(void)
+{
+    // Call our function echo whenever the serial line receives data
+    serial.attach(&echo, UnbufferedSerial::RxIrq);
+}

Tutorials_Debugging/DebugPrintf_BlinksLED/main.cpp

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+DigitalOut led1(LED1);
+
+int main()
+{
+    while (true) {
+        led1 = !led1;
+
+        // Print something over the serial connection
+        printf("Blink! LED is now %d\r\n", led1.read());
+        ThisThread::sleep_for(500);
+    }
+}

Tutorials_Debugging/DebugPrintf_SetBaudRate/main.cpp

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+BufferedSerial pc(USBTX, USBRX);
+
+int main()
+{
+    pc.set_baud(9600);
+    char msg[] = "Hello World!\r\n";
+    pc.write(msg, sizeof(msg));
+}

Tutorials_SerialComm/Serial_EchoBack/main.cpp

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2006-2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+static BufferedSerial pc(USBTX, USBRX);
+
+int main()
+{
+    char msg[] = "Echoes back to the screen anything you type\n";
+    char *buff = new char[1];
+    pc.write(msg, sizeof(msg));
+    while (1) {
+        pc.read(buff, sizeof(buff));
+        pc.write(buff, sizeof(buff));
+    }
+}

Tutorials_SerialComm/Serial_HelloWorld/main.cpp

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2006-2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+static BufferedSerial pc(USBTX, USBRX); // tx, rx
+
+int main()
+{
+    char msg[] = "Hello World!\n";
+    pc.write(msg, sizeof(msg));
+    while (1);
+}

Tutorials_SerialComm/Serial_LEDControl/main.cpp

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2006-2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+static BufferedSerial pc(USBTX, USBRX); // tx, rx
+PwmOut led(LED1);
+
+float brightness = 0.0;
+
+int main()
+{
+    char msg[] = "Press 'u' to turn LED1 brightness up, 'd' to turn it down\n";
+    char *c = new char[1];
+    pc.write(msg, sizeof(msg));
+
+    while (1) {
+        pc.read(c, sizeof(c));
+        pc.write(c, sizeof(c));
+        if ((*c == 'u') && (brightness < 0.5)) {
+            brightness += 0.01;
+            led = brightness;
+        }
+        if ((*c == 'd') && (brightness > 0.0)) {
+            brightness -= 0.01;
+            led = brightness;
+        }
+    }
+
+}

Tutorials_SerialComm/Serial_PassCharacters/main.cpp

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2006-2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+static BufferedSerial pc(USBTX, USBRX);
+static BufferedSerial uart(D1, D0);
+
+DigitalOut pc_activity(LED1);
+DigitalOut uart_activity(LED2);
+
+int main()
+{
+    char *pc2uart = new char[1];
+    char *uart2pc = new char[1];
+    while (1) {
+        if (pc.readable()) {
+            pc.read(pc2uart, sizeof(pc2uart));
+            uart.write(pc2uart, sizeof(pc2uart));
+            pc_activity = !pc_activity;
+        }
+        if (uart.readable()) {
+            uart.read(uart2pc, sizeof(uart2pc));
+            pc.write(uart2pc, sizeof(uart2pc));
+            uart_activity = !uart_activity;
+        }
+    }
+}

Tutorials_SerialComm/Serial_ReadToBuffer/main.cpp

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+// Create a serial object
+static BufferedSerial pc(USBTX, USBRX);
+
+int main(void)
+{
+    char buffer[10] = {};
+    while (1) {
+        if (pc.readable()) {
+            ThisThread::sleep_for(100);
+            pc.read(buffer, 10);
+            printf("I got '%s'\n", buffer);
+        }
+    }
+}

Tutorials_SerialComm/Serial_STDOUT/main.cpp

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2006-2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+int main()
+{
+    printf("Hello World!\n");
+    while (1);
+}