Added HW demo for triple buffer [WIP]

1 files changed, 212 insertions, 0 deletions

diff --git a/demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c b/demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c
new file mode 100644
index 0000000..5545a74
--- /dev/null
+++ b/demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c
@@ -0,0 +1,212 @@
+/*
+    Copyright (C) 2013-2015 Andrea Zoppi
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+#include "ch.h"
+#include "hal.h"
+
+#include "chprintf.h"
+#if HAL_USE_SERIAL_USB
+#include "usbcfg.h"
+#endif
+
+#include "tribuf.h"
+
+
+/*===========================================================================*/
+/* TriBuf related.                                                           */
+/*===========================================================================*/
+
+#define WRITE_DELAY         2
+#define READ_DELAY          1
+
+#define WRITER_WA_SIZE      256
+
+static thread_t *writertp;
+
+static tribuf_t tribuf;
+static char buffers[3];
+
+static const char text[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\r\n";
+
+/*
+ * Reads from the front buffer.
+ */
+static char read_front(void) {
+
+  const char *front;
+  msg_t error;
+
+  chSysLock();
+  error = tribufWaitReadyTimeoutS(&tribuf, MS2ST(1000));
+  if (error != MSG_OK)
+    chSysHalt("ERROR: read_front timeout");
+  tribufSwapFrontI(&tribuf);
+  front = (const char *)tribufGetFrontI(&tribuf);
+  chSysUnlock();
+  return *front;
+}
+
+/*
+ * Overwrites the back buffer with the provided character.
+ */
+static void write_back(char c) {
+
+  char *back;
+
+  chSysLock();
+  back = (char *)tribufGetBackI(&tribuf);
+  *back = c;
+  tribufSwapBackI(&tribuf);
+  chSysUnlock();
+}
+
+/*
+ * Overwrites the back buffer with a fixed text, character by character.
+ */
+static THD_WORKING_AREA(writer_wa, WRITER_WA_SIZE);
+static THD_FUNCTION(writer_thread, arg) {
+
+  const uint32_t delay = (uint32_t)(msg_t)arg;
+  size_t i;
+
+  for (;;) {
+    for (i = 0; i < sizeof(text); ++i) {
+      write_back(text[i]);
+      chThdSleepMilliseconds(delay);
+    }
+  }
+}
+
+/*===========================================================================*/
+/* MISC.                                                                     */
+/*===========================================================================*/
+
+#if HAL_USE_SERIAL_USB
+/* Virtual serial port over USB.*/
+SerialUSBDriver SDU1;
+static BaseSequentialStream *const chout = (BaseSequentialStream *)&SDU1;
+#else
+static BaseSequentialStream *const chout = (BaseSequentialStream *)&SD1;
+#endif
+
+/*
+ * Red LED blinker thread, times are in milliseconds.
+ */
+static THD_WORKING_AREA(waThread1, 128);
+static THD_FUNCTION(Thread1, arg) {
+
+  (void)arg;
+  chRegSetThreadName("blinker1");
+  while (true) {
+    palClearPad(GPIOG, GPIOG_LED4_RED);
+    chThdSleepMilliseconds(500);
+    palSetPad(GPIOG, GPIOG_LED4_RED);
+    chThdSleepMilliseconds(500);
+  }
+}
+
+/*
+ * Green LED blinker thread, times are in milliseconds.
+ */
+static THD_WORKING_AREA(waThread2, 128);
+static THD_FUNCTION(Thread2, arg) {
+
+  (void)arg;
+  chRegSetThreadName("blinker2");
+  while (true) {
+    palClearPad(GPIOG, GPIOG_LED3_GREEN);
+    chThdSleepMilliseconds(250);
+    palSetPad(GPIOG, GPIOG_LED3_GREEN);
+    chThdSleepMilliseconds(250);
+  }
+}
+
+/*===========================================================================*/
+/* Initialization and main thread.                                           */
+/*===========================================================================*/
+
+/*
+ * Application entry point.
+ */
+int main(void) {
+
+  /*
+   * System initializations.
+   * - HAL initialization, this also initializes the configured device drivers
+   *   and performs the board-specific initializations.
+   * - Kernel initialization, the main() function becomes a thread and the
+   *   RTOS is active.
+   */
+  halInit();
+  chSysInit();
+
+#if HAL_USE_SERIAL_USB
+  /*
+   * Initializes a serial-over-USB CDC driver.
+   */
+  sduObjectInit(&SDU1);
+  sduStart(&SDU1, &serusbcfg);
+
+  /*
+   * Activates the USB driver and then the USB bus pull-up on D+.
+   * Note, a delay is inserted in order to not have to disconnect the cable
+   * after a reset.
+   */
+  usbDisconnectBus(serusbcfg.usbp);
+  chThdSleepMilliseconds(1000);
+  usbStart(serusbcfg.usbp, &usbcfg);
+  usbConnectBus(serusbcfg.usbp);
+#else
+  /*
+   * Initializes serial port.
+   */
+  sdStart(&SD1, NULL);
+#endif /* HAL_USE_SERIAL_USB */
+
+  /*
+   * Triple buffer handler initialization.
+   */
+  tribufObjectInit(&tribuf, &buffers[0], &buffers[1], &buffers[2]);
+
+  /*
+   * Creating the blinker threads.
+   */
+  chThdCreateStatic(waThread1, sizeof(waThread1),
+                    NORMALPRIO + 10, Thread1, NULL);
+  chThdCreateStatic(waThread2, sizeof(waThread2),
+                    NORMALPRIO + 10, Thread2, NULL);
+
+  /*
+   * Writer thread started.
+   */
+  writertp = chThdCreateStatic(writer_wa, sizeof(writer_wa),
+                               (NORMALPRIO + 1),
+                               writer_thread, (void *)WRITE_DELAY);
+
+  /*
+   * Reads from the front buffer.
+   */
+  while (!chThdTerminatedX(writertp)) {
+    chprintf(chout, "%c", read_front());
+    chThdSleepMilliseconds(READ_DELAY);
+  }
+
+  chThdRelease(writertp);
+  for (;;)
+    chThdSleepMilliseconds(100);
+  return 0;
+}
+