1 files changed, 103 insertions, 0 deletions
diff --git a/libmaple/util.c b/libmaple/util.c
new file mode 100644
index 0000000..d323611
--- /dev/null
+++ b/libmaple/util.c
@@ -0,0 +1,103 @@
+/* *****************************************************************************
+ *  This program is free software: you can redistribute it 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 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 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/>.
+ *
+ *  Created: 12/18/09 02:38:44
+ *  Copyright (c) 2009 Perry L. Hung. All rights reserved.
+ *
+ * ****************************************************************************/
+
+/**
+ *  @file util.h
+ *
+ *  @brief Utility procedures for debugging, mostly an error LED fade and
+ *  messages dumped over a uart for failed asserts.
+ */
+
+#include "libmaple.h"
+#include "usart.h"
+#include "gpio.h"
+#include "nvic.h"
+#include "adc.h"
+#include "timers.h"
+
+#define ERROR_LED_PORT         GPIOA_BASE
+#define ERROR_LED_PIN          5
+#define ERROR_USART_NUM        2
+#define ERROR_USART_BAUD       9600
+#define ERROR_TX_PIN           2
+#define ERROR_TX_PORT          GPIOA_BASE
+
+/* Error assert + fade */
+void _fail(const char* file, int line, const char* exp) {
+    int32_t  slope   = 1;
+    int32_t CC      = 0x0000;
+    int32_t TOP_CNT = 0x02FF;
+    int32_t i       = 0;
+
+    /* Turn off interrupts */
+    nvic_disable_interrupts();
+
+    /* Turn off timers  */
+    timers_disable();
+
+    /* Turn off ADC */
+    adc_disable();
+
+    /* Turn off all usarts  */
+    usart_disable(1);
+    usart_disable(2);
+    usart_disable(3);
+
+    /* Initialize the error usart */
+    gpio_set_mode(ERROR_TX_PORT, ERROR_TX_PIN, GPIO_MODE_AF_OUTPUT_PP);
+    usart_init(ERROR_USART_NUM, ERROR_USART_BAUD);
+
+    /* Print failed assert message  */
+    usart_putstr(ERROR_USART_NUM, "ERROR: FAILED ASSERT(");
+    usart_putstr(ERROR_USART_NUM, exp);
+    usart_putstr(ERROR_USART_NUM, "): ");
+    usart_putstr(ERROR_USART_NUM, file);
+    usart_putstr(ERROR_USART_NUM, ": ");
+    usart_putudec(ERROR_USART_NUM, line);
+    usart_putc(ERROR_USART_NUM, '\n');
+
+    /* Turn on the error LED  */
+    gpio_set_mode(ERROR_LED_PORT, ERROR_LED_PIN, GPIO_MODE_OUTPUT_PP);
+
+    /* Turn the USB interrupt back on so the bootloader keeps on functioning  */
+    nvic_enable_interrupt(NVIC_INT_USBHP);
+    nvic_enable_interrupt(NVIC_INT_USBLP);
+
+    /* Error fade  */
+    while (1) {
+        if (CC == TOP_CNT)  {
+            slope = -1;
+        } else if (CC == 0) {
+            slope = 1;
+        }
+
+        if (i == TOP_CNT)  {
+            CC += slope;
+            i = 0;
+        }
+
+        if (i < CC) {
+            gpio_write_bit(ERROR_LED_PORT, ERROR_LED_PIN, 1);
+        } else {
+            gpio_write_bit(ERROR_LED_PORT, ERROR_LED_PIN, 0);
+        }
+        i++;
+    }
+}
+