From cf1ac4b7e8c1e53b1fe7dac5b4c48ffa44fb65de Mon Sep 17 00:00:00 2001
From: fruchti <fruchti@gvfr.de>
Date: Sat, 4 Aug 2018 16:11:18 +0200
Subject: [PATCH] Add servo control for paper cutter

---
 build-number.txt |  2 +-
 src/ltp1245.c    | 88 ++++++++++++++++++++++++++++++++++++++++++++++--
 src/ltp1245.h    |  2 ++
 src/main.c       |  9 ++---
 4 files changed, 91 insertions(+), 10 deletions(-)

diff --git a/build-number.txt b/build-number.txt
index 485369e..3d4c7bf 100644
--- a/build-number.txt
+++ b/build-number.txt
@@ -1 +1 @@
-205
+220
diff --git a/src/ltp1245.c b/src/ltp1245.c
index 1f9ead4..ec17793 100644
--- a/src/ltp1245.c
+++ b/src/ltp1245.c
@@ -18,6 +18,7 @@ static State_t State_Idle(void);
 static State_t State_PaperLoad(void);
 static State_t State_Printing(void);
 static State_t State_PaperFeed(void);
+static State_t State_Cutting(void);
 static volatile State_t State = {State_Idle};
 
 static void InitStepper(void)
@@ -70,7 +71,7 @@ static void InitDataLines(void)
     RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
     RCC->AHBENR |= RCC_AHBENR_DMA1EN;
 
-    TIM2->PSC = 719;                // Each tick corresponds to ten microseconds
+    TIM2->PSC = 720 - 1;            // Each tick corresponds to ten microseconds
     TIM2->ARR = 201;                // 2 milliseconds
     TIM2->CCR3 = 1;
     TIM2->CCR4 = 1;
@@ -114,8 +115,8 @@ static void InitThermistor(void)
     RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
 
     GPIOB->CRL = (GPIOB->CRL
-        & ~(0x0f << PIN_THERMISTOR))
-        | (0x00 << PIN_THERMISTOR)          // Analog mode
+        & ~(0x0f << (4 * PIN_THERMISTOR)))
+        | (0x00 << (4 * PIN_THERMISTOR))    // Analog mode
         ;
     
     // Enable ADC
@@ -139,6 +140,27 @@ static void InitThermistor(void)
     ADC1->CR2 |= ADC_CR2_ADON;
 }
 
+static void InitCutter(void)
+{
+    RCC->APB1ENR |= RCC_APB1ENR_TIM4EN;
+    RCC->APB2ENR |= RCC_APB2ENR_IOPBEN;
+
+    GPIOB->CRL = (GPIOB->CRL
+        & ~(0xf << (4 * PIN_PAPER_CUT)))
+        | (0x09 << (4 * PIN_PAPER_CUT))     // Output in AF mode, max. 10 MHz
+        ;
+
+    // Servo pulse length should be between 1 and 2 ms with a period of 20 ms
+    TIM4->PSC = 72 - 1;     // Divide to one microsecond
+    TIM4->ARR = 20000;      // 50 Hz frequency
+    TIM4->CCR2 = 1000;      // 1 millisecond
+    TIM4->CCMR1 = TIM_CCMR1_OC2M_2 | TIM_CCMR1_OC2M_1;
+    TIM4->CR1 = TIM_CR1_CEN;
+    TIM4->CCER = TIM_CCER_CC2E;
+
+    NVIC_EnableIRQ(TIM4_IRQn);
+}
+
 static bool HasPaper(void)
 {
     return !(GPIOB->IDR & (1 << PIN_PAPER));
@@ -253,6 +275,17 @@ static State_t State_PaperFeed(void)
     return (State_t){State_PaperFeed};
 }
 
+static State_t State_Cutting(void)
+{
+    // The timer interrupt is deactived once a sufficient number of pulses is
+    // generated
+    if(~TIM4->DIER & TIM_DIER_UIE)
+    {
+        return (State_t){State_Idle};
+    }
+    return (State_t){State_Cutting};
+}
+
 static State_t State_Idle(void)
 {
     if(!HasPaper())
@@ -309,8 +342,30 @@ LTP1245_Result_t LTP1245_FeedPaper(int lines)
     return LTP1245_OK;
 }
 
+LTP1245_Result_t LTP1245_Cut(void)
+{
+    do
+    {
+        if(!HasPaper())
+        {
+            return LTP1245_NO_PAPER;
+        }
+        if(!HeadDown())
+        {
+            return LTP1245_HEAD_UP;
+        }
+    } while(State.fn != State_Idle);
+
+    TIM4->CCR2 = 2000;
+    TIM4->DIER = TIM_DIER_UIE;
+    State = (State_t){State_Cutting};
+
+    return LTP1245_OK;
+}
+
 void LTP1245_Init(void)
 {
+    InitCutter();
     InitDataLines();
     InitSensors();
     InitStepper();
@@ -435,6 +490,33 @@ void ADC1_2_IRQHandler(void)
         / (int)((5 * 1.4 - 2.9) * (5 * 1.4 - 2.9));
 }
 
+void TIM4_IRQHandler(void)
+{
+    if(TIM4->SR & TIM_SR_UIF)
+    {
+        static int ct = 0;
+
+        if(ct == 0)
+        {
+            ct = LTP1245_CUT_DURATION;
+        }
+        else
+        {
+            ct--;
+            if(ct == 0)
+            {
+                TIM4->DIER &= ~TIM_DIER_UIE;
+            }
+            else if(ct == LTP1245_CUT_DURATION / 2)
+            {
+                TIM4->CCR2 = 1000;      // Back to -90 deg
+            }
+        }
+
+        TIM4->SR &= ~TIM_SR_UIF;
+    }
+}
+
 void DMA1_Channel5_IRQHandler(void)
 {
     DMA1->IFCR = DMA_IFCR_CTCIF5;
diff --git a/src/ltp1245.h b/src/ltp1245.h
index 8b4b903..8f6edf2 100644
--- a/src/ltp1245.h
+++ b/src/ltp1245.h
@@ -13,6 +13,7 @@ typedef enum
 } LTP1245_Result_t;
 
 #define LTP1245_MAX_DRIVE_FREQ  473     // In Hz
+#define LTP1245_CUT_DURATION    50      // In steps of 20 ms
 #define LTP1245_BUFFER_LINES    64
 #define LTP1245_LINEWIDTH       384     // In pixels
 #define LTP1245_LINE_BYTES      (LTP1245_LINEWIDTH / 8)
@@ -22,3 +23,4 @@ typedef enum
 void LTP1245_Init(void);
 LTP1245_Result_t LTP1245_FeedPaper(int lines);
 LTP1245_Result_t LTP1245_Print(uint8_t *data, int lines);
+LTP1245_Result_t LTP1245_Cut(void);
diff --git a/src/main.c b/src/main.c
index a648914..dbe8910 100755
--- a/src/main.c
+++ b/src/main.c
@@ -13,12 +13,9 @@ int main(void)
     // LTP1245_FeedPaper(10);
     // Print_Text("Testy McTestFace", &Arpegius_32);
     // Print_Text("123555bcD", &Messe_Duesseldorf_39);
-    Print_Text("Abcdef Ghi Jkl", &Hannover_Messe_Serif_26);
-    Print_Text("Abcdef Ghi Jkl", &Hannover_Messe_Serif_26);
-    Print_Text("Abcdef Ghi Jkl", &Hannover_Messe_Serif_26);
-    Print_Text("Abcdef Ghi Jkl", &Hannover_Messe_Serif_26);
-    Print_Text("Abcdef Ghi Jkl", &Hannover_Messe_Serif_26);
-    LTP1245_FeedPaper(100);
+    Print_Text("This is a long line with very much text!", &Hannover_Messe_Serif_26);
+    LTP1245_FeedPaper(10);
+    LTP1245_Cut();
 
     for(;;)
     {