got LEDs working, ribbon trail program initially implemented

- fixed soft I2C master set hi/lo routines
- fixed bug in matrix_send not setting all LEDs from map
- fix AWU interrupt not firing; requires EXTI line to be configured too even if unused
- fixed wrong dividers used in system clock set function

firmware/app/main.c

@@ -47,10 +47,15 @@ void clk_init()
 
 void periphclk_init()
 {
+    // needed for GPIO, remap, ADC, SPI
     RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |
                            RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO  |
                            RCC_APB2Periph_ADC1  | RCC_APB2Periph_SPI1, ENABLE);
 
+    // may be needed for AWU
+    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
+
+    // needed for DMA, USBPD
     RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1 | RCC_AHBPeriph_USBPD, ENABLE);
 }
 
@@ -100,6 +105,31 @@ void gpio_init()
     // todo later
 }
 
+void awu_init()
+{
+    NVIC_InitTypeDef nvic;
+    EXTI_InitTypeDef exti = {0};
+
+    // configure AWU
+    AWU_SetPrescaler(AWU_Prescaler_1);
+    AWU_SetWindowValue(0x2f);
+    AutoWakeUpCmd(ENABLE);
+
+    // configure EXTI line
+    exti.EXTI_Line = EXTI_Line27;
+    exti.EXTI_Mode = EXTI_Mode_Interrupt;
+    exti.EXTI_Trigger = EXTI_Trigger_Rising;
+    exti.EXTI_LineCmd = ENABLE;
+    EXTI_Init(&exti);
+
+    // configure PFIC interrupt
+    nvic.NVIC_IRQChannel = AWU_IRQn;
+    nvic.NVIC_IRQChannelPreemptionPriority = 0;
+    nvic.NVIC_IRQChannelSubPriority = 0;
+    nvic.NVIC_IRQChannelCmd = ENABLE;
+    NVIC_Init(&nvic);
+}
+
 
 
 /*********************************************************************
@@ -130,22 +160,20 @@ int main(void)
     // set up accelerometer
     spim_init();
 
-    // configure AWU to provide ~1440Hz wakeup interrupt for main program
+    // configure AWU to provide ~997Hz wakeup interrupt for main program
     // TODO: confirm if the counter is reset / preloaded
-    AWU_SetPrescaler(AWU_Prescaler_32);
-    AWU_SetWindowValue(0x3e);
-    AutoWakeUpCmd(ENABLE);
+    awu_init();
 
     while (1) {
         // low-priority tasks like
         // rendering next LED program output frame
         if (lp_render) {
             lp_render = 0;
-            lp_ribbon_upward(800, 3, 2);
+            lp_ribbon_upward(200, 3, 4);            
         }
 
         // stay a while
-        // __WFI();
+        __WFI();
     }
 }
 
@@ -154,13 +182,13 @@ void AWU_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));
 void AWU_IRQHandler(void)
 {
     cnt++;
-    if (cnt >= 1440) {
+    if (cnt >= 1000) {
         cnt = 0;
         wake_uptime++;
     }
 
-    // handle render new frame at 90Hz
-    if ((cnt & 0xf) == 0) {
+    // handle render new frame at ~100Hz
+    if ((cnt % 10) == 0) {
         lp_render = 1;
     }
 
@@ -172,4 +200,7 @@ void AWU_IRQHandler(void)
     // handle buttons
 
     // do we sleep?
+
+    // clear interrupt
+    EXTI_ClearFlag(EXTI_Line27);
 }