Added workshop example for bluetooth communication

diff --git a/Workshops/TUES_bluetooth_demo/TUES_bluetooth_demo.ino b/Workshops/TUES_bluetooth_demo/TUES_bluetooth_demo.ino
new file mode 100644 (file)
index 0000000..bb73d6a
--- /dev/null
+++ b/Workshops/TUES_bluetooth_demo/TUES_bluetooth_demo.ino
@@ -0,0 +1,111 @@
+/*
+       TUES Bluetooth Demo - an example for controlling motors over Bluetooth
+       Copyright (C) 2023 Vladimir Garistov <vgaristov@elsys-bg.org>
+
+       This program is free software: you can redistribute it and/or modify
+       it under the terms of the GNU Affero General Public License as published
+       by the Free Software Foundation, either version 3 of the License, or
+       (at your option) any later version.
+
+       This program 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 Affero General Public License for more details.
+
+       You should have received a copy of the GNU Affero General Public License
+       along with this program.  If not, see <https://www.gnu.org/licenses/>
+*/
+
+// Board selection. Comment out for Arduino AVR boards.
+#define _ESP32_
+
+// Dabble configuration options
+#define CUSTOM_SETTINGS
+#define INCLUDE_TERMINAL_MODULE
+#ifdef _ESP32_
+       // Does not compile with increased warnings in Arduino IDE because some are treated as errors.
+       #include <DabbleESP32.h>
+#else
+       #include <Dabble.h>
+#endif
+
+#ifdef _ESP32_
+       #if !defined(CONFIG_BT_ENABLED) || !defined(CONFIG_BT_BLUEDROID_ENABLED)
+               #error Bluetooth is not enabled! Please run `make menuconfig` to enable it.
+       #endif
+
+       #if !defined(CONFIG_BT_SPP_ENABLED)
+               #error Serial Port Profile for Bluetooth is not available or not enabled.
+       #endif
+#else
+       #define RX_PIN          2
+       #define TX_PIN          3
+       #define BT_BAUDRATE     9600
+#endif
+
+#define UART_BAUDRATE  38400
+#define UART_TIMEOUT   10              // ms
+
+static void serial_relay(void);
+
+#ifdef _ESP32_
+       static const char device_name[] = "ESP32-BT-Slave";
+#endif
+
+void setup()
+{
+       #ifdef _ESP32_
+               Dabble.begin(device_name);
+       #else
+               Dabble.begin(BT_BAUDRATE, RX_PIN, TX_PIN);
+       #endif
+
+       Serial.begin(UART_BAUDRATE);
+       Serial.setTimeout(UART_TIMEOUT);
+       Serial.println("Setup complete.");
+}
+
+void loop()
+{
+       // This function is used to refresh data obtained from smartphone.
+       // Hence calling this function is mandatory in order to get data properly from your mobile.
+       Dabble.processInput();
+       serial_relay();
+}
+
+/*
+       Relays data from the Bluetooth module to the UART interface and vice-versa.
+       A maximum of 256 characters can be sent from the UART interface to the Bluetooth module.
+       Otherwise the buffer of the Serial library fills up and characters are silently dropped.
+       A maximum of 64 characters can be sent from the Bluetooth module to the UART interface.
+       In this case the buffer of the Dabble library fills up. Result is the same - some
+       characters are silently dropped.
+       Does not work correctly for non-ASCII characters.
+       Tested on Arduino Uno and ESP32, the lenght limits might differ on other boards.
+*/
+static void serial_relay(void)
+{
+       static String serial_data = "";
+       static bool data_flag = false;
+
+       if (Serial.available())
+       {
+               // Blocks for UART_TIMEOUT
+               serial_data = Serial.readString();
+               data_flag = true;
+       }
+       if (data_flag == true)
+       {
+               Terminal.print(serial_data);
+               serial_data = "";
+               data_flag = false;
+       }
+       if (Terminal.available())
+       {
+               while (Terminal.available())
+               {
+                       Serial.write(Terminal.read());
+               }
+               Serial.println();
+       }
+}