1 files changed, 69 insertions, 0 deletions
diff --git a/stm/usrsw.c b/stm/usrsw.c
new file mode 100644
index 0000000000..385547843f
--- /dev/null
+++ b/stm/usrsw.c
@@ -0,0 +1,69 @@
+#include <stm_misc.h>
+#include <stm32f4xx_gpio.h>
+#include <stm32f4xx_exti.h>
+#include <stm32f4xx_syscfg.h>
+#include <stm32f4xx_rcc.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "obj.h"
+#include "usrsw.h"
+
+#define PYB_USRSW_PORT (GPIOA)
+#define PYB_USRSW_PIN (GPIO_Pin_13)
+
+void switch_init(void) {
+    // make it an input with pull-up
+    GPIO_InitTypeDef GPIO_InitStructure;
+    GPIO_InitStructure.GPIO_Pin = PYB_USRSW_PIN;
+    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
+    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
+    GPIO_Init(PYB_USRSW_PORT, &GPIO_InitStructure);
+
+    // the rest does the EXTI interrupt
+
+    /* Enable SYSCFG clock */
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
+
+    /* Connect EXTI Line13 to PA13 pin */
+    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource13);
+
+    /* Configure EXTI Line13, rising edge */
+    EXTI_InitTypeDef EXTI_InitStructure;
+    EXTI_InitStructure.EXTI_Line = EXTI_Line13;
+    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
+    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
+    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
+    EXTI_Init(&EXTI_InitStructure);
+
+    /* Enable and set EXTI15_10 Interrupt to the lowest priority */
+    NVIC_InitTypeDef NVIC_InitStructure;
+    NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;
+    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F;
+    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F;
+    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
+    NVIC_Init(&NVIC_InitStructure);
+}
+
+int switch_get(void) {
+    if (PYB_USRSW_PORT->IDR & PYB_USRSW_PIN) {
+        // pulled high, so switch is not pressed
+        return 0;
+    } else {
+        // pulled low, so switch is pressed
+        return 1;
+    }
+}
+
+/******************************************************************************/
+/* Micro Python bindings                                                      */
+
+static mp_obj_t pyb_switch(void) {
+    if (switch_get()) {
+        return mp_const_true;
+    } else {
+        return mp_const_false;
+    }
+}
+
+MP_DEFINE_CONST_FUN_OBJ_0(pyb_switch_obj, pyb_switch);