Add pen state control

stm32f103c8t6/build_number.txt

@@ -1 +1 @@
-246
+250

stm32f103c8t6/src/pinning.h

@@ -3,6 +3,7 @@
 // Port A
 #define PIN_OUTPUT_X            8   // PA8  - TIM1_CH1
 #define PIN_OUTPUT_Y            9   // PA9  - TIM1_CH2
+#define PIN_PEN_STATE           10  // PA10
 #define PIN_USB_DM              11  // PA11 - USB_DM
 #define PIN_USB_DP              12  // PA12 - USB_DP
 // #define PIN_USB_PULLUP          15  // PA15 - 1.5 kΩ to D+

stm32f103c8t6/src/pwm_output.c

@@ -7,10 +7,13 @@
 
 MODULE_OWNS_PIN(GPIOA, PIN_OUTPUT_X);
 MODULE_OWNS_PIN(GPIOA, PIN_OUTPUT_Y);
+MODULE_OWNS_PIN(GPIOA, PIN_PEN_STATE);
 
 static HPGL_Movement_t Output_Buffer[CONFIG_BUFFER_MOVEMENTS];
 static const HPGL_Movement_t *Output_BufferRead = Output_Buffer;
 static HPGL_Movement_t *Output_BufferWrite = Output_Buffer;
+static bool Output_PenIsDown;
+static unsigned int Output_DelayCounter = 0;
 
 typedef struct
 {
@@ -52,6 +55,18 @@ bool Output_EnqueueMovement(HPGL_Movement_t movement)
     return true;
 }
 
+static void Output_PenDown(void)
+{
+    GPIOA->BRR = (1 << PIN_PEN_STATE);
+    Output_PenIsDown = true;
+}
+
+static void Output_PenUp(void)
+{
+    GPIOA->BSRR = (1 << PIN_PEN_STATE);
+    Output_PenIsDown = false;
+}
+
 static bool Output_FetchNextPoint(void)
 {
     if(Output_BufferRead == Output_BufferWrite)
@@ -60,6 +75,20 @@ static bool Output_FetchNextPoint(void)
     }
 
     const HPGL_Movement_t *movement = Output_BufferRead;
+    if(movement->pen_down != Output_PenIsDown)
+    {
+        if(movement->pen_down)
+        {
+            Output_PenDown();
+        }
+        else
+        {
+            Output_PenUp();
+        }
+        Output_DelayCounter = OUTPUT_PEN_DELAY;
+        return false;
+    }
+
     Output_TargetPoint.x = movement->x;
     Output_TargetPoint.y = movement->y;
     // TODO: Handle pen state
@@ -94,7 +123,7 @@ static int Output_ApproximateLength(int dx, int dy)
     }
 }
 
-static void Output_Position()
+static void Output_Position(void)
 {
     uint16_t compare_x = OUTPUT_PWM_OFFSET + Output_CurrentPoint.x;
     uint16_t compare_y = OUTPUT_PWM_OFFSET + Output_CurrentPoint.y;
@@ -105,6 +134,12 @@ static void Output_Position()
 
 void Output_Tick(void)
 {
+    if(Output_DelayCounter > 0)
+    {
+        Output_DelayCounter--;
+        return;
+    }
+
     int step_length = Output_CurrentVelocity;
     while(true)
     {
@@ -138,11 +173,15 @@ void Output_Init(void)
     RCC->APB2ENR |= RCC_APB2ENR_TIM1EN;
     RCC->APB2ENR |= RCC_APB2ENR_IOPAEN;
 
+    Output_PenUp();
+
     GPIOA->CRH = (GPIOA->CRH
         & ~(0xf << (4 * PIN_OUTPUT_X - 32))
-        & ~(0xf << (4 * PIN_OUTPUT_Y - 32)))
+        & ~(0xf << (4 * PIN_OUTPUT_Y - 32))
+        & ~(0xf << (4 * PIN_PEN_STATE - 32)))
         | (0xa << (4 * PIN_OUTPUT_X - 32))  // AF output, 2 MHz
         | (0xa << (4 * PIN_OUTPUT_Y - 32))  // AF output, 2 MHz
+        | (0x6 << (4 * PIN_PEN_STATE - 32)) // OD output, 2 MHz
         ;
 
     TIM1->CCMR1 = TIM_CCMR1_OC1PE | TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1M_1

stm32f103c8t6/src/pwm_output.h

@@ -4,6 +4,7 @@
 
 #define OUTPUT_PWM_RESOLUTION   15  // In bits
 #define OUTPUT_PWM_OFFSET       300 // Minimum value
+#define OUTPUT_PEN_DELAY        200 // In timer ticks
 
 #define OUTPUT_RESOLUTION       14  // In bits
 #define OUTPUT_COORDINATE_LIMIT ((1 << OUTPUT_RESOLUTION) - 1)