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authorUwe Hermann2009-07-18 16:22:45 +0200
committerUwe Hermann2009-07-18 16:22:45 +0200
commit74db299094a2745f1113b8b8173bce2911350fd5 (patch)
tree6404981cfa7c18d989def446126a61ea8dc344b4
parent3262983d27ee15fefeaa2efbe9a903f5364d7ee2 (diff)
Add examples for LED blinking code, both, manually and using the API.
-rw-r--r--example/blink.c30
1 files changed, 23 insertions, 7 deletions
diff --git a/example/blink.c b/example/blink.c
index 21ac147..7e83710 100644
--- a/example/blink.c
+++ b/example/blink.c
@@ -24,16 +24,33 @@ int main(void)
{
int i;
- /* GPIO setup: Enable GPIOC clock, set GPIO12 to 'output push-pull'. */
+ /* Enable GPIOC clock. */
RCC_APB2ENR = RCC_IOPCEN;
- GPIOC_CRH = (GPIO_CNF_OUTPUT_PUSHPULL << (((12 - 8) * 4) + 2));
- GPIOC_CRH |= (GPIO_MODE_OUTPUT_2_MHZ << ((12 - 8) * 4));
+
+ /* Set GPIO12 (in GPIO port C) to 'output push-pull'. */
+ /* Manually: */
+ // GPIOC_CRH = (GPIO_CNF_OUTPUT_PUSHPULL << (((12 - 8) * 4) + 2));
+ // GPIOC_CRH |= (GPIO_MODE_OUTPUT_2_MHZ << ((12 - 8) * 4));
+ /* Using API functions: */
+ gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_2_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
/* Blink the LED (PC12) on the board. */
while (1) {
- GPIOC_BSRR = GPIO12; /* LED off */
- for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */
- GPIOC_BRR = GPIO12; /* LED on */
+ /* Manually: */
+ // GPIOC_BSRR = GPIO12; /* LED off */
+ // for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */
+ // GPIOC_BRR = GPIO12; /* LED on */
+ // for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */
+
+ /* Using API functions gpio_set()/gpio_clear(): */
+ // gpio_set(GPIOC, GPIO12); /* LED off */
+ // for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */
+ // gpio_clear(GPIOC, GPIO12); /* LED on */
+ // for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */
+
+ /* Using API function gpio_toggle(): */
+ gpio_toggle(GPIOC, GPIO12); /* LED on/off */
for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */
}
@@ -44,4 +61,3 @@ u32 *vector_table[2] __attribute__ ((section(".vectors"))) = {
(u32 *)0x20000800, /* Use 2 KB stack (0x800 bytes). */
(u32 *)main, /* Use main() as reset vector for now. */
};
-