Improve switiching between spi modes

midi2cv/drivers/display.cc

@@ -4,6 +4,7 @@
 #include "stmlib/utils/random.h"
 #include <stm32f37x_conf.h>
 #include <u8g2.h>
+#include "spi_mode.h"
 
 using namespace stmlib;
 
@@ -21,6 +22,8 @@ u8g2_t* Display::u8g2()
     return &u8g2_;
 }
 
+void InitSPI(void);
+
 void Display::Init()
 {
     // init SS/CS/RST GPIO
@@ -53,19 +56,7 @@ void Display::Init()
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
     SPI_I2S_DeInit(SPI2);
     // Initialize SPI
-    SPI_InitTypeDef spi_init;
-    spi_init.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
-    spi_init.SPI_Mode = SPI_Mode_Master;
-    spi_init.SPI_DataSize = SPI_DataSize_8b;
-    spi_init.SPI_CPOL = SPI_CPOL_High;
-    spi_init.SPI_CPHA = SPI_CPHA_2Edge;
-    spi_init.SPI_NSS = SPI_NSS_Soft;
-    spi_init.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;
-    spi_init.SPI_FirstBit = SPI_FirstBit_MSB;
-    spi_init.SPI_CRCPolynomial = 7;
-    SPI_Init(SPI2, &spi_init);
-    SPI_Cmd(SPI2, ENABLE);
-
+    InitSPI(SPI_MODE_DISPLAY);
     GPIO_WriteBit(GPIOB, kPinReset, Bit_RESET);
     asm("nop");
 
@@ -73,6 +64,7 @@ void Display::Init()
     InitGLib();
 }
 
+
 uint8_t u8x8_stm32_gpio_and_delay(U8X8_UNUSED u8x8_t* u8x8,
     U8X8_UNUSED uint8_t msg, U8X8_UNUSED uint8_t arg_int,
     U8X8_UNUSED void* arg_ptr)
@@ -104,6 +96,7 @@ uint8_t u8x8_byte_4wire_hw_spi(u8x8_t* u8x8, uint8_t msg, uint8_t arg_int,
 	    GPIO_WriteBit(GPIOB, kPinDataCommand, Bit_RESET);
 	break;
     case U8X8_MSG_BYTE_START_TRANSFER:
+	InitSPI(SPI_MODE_DISPLAY);
 	GPIO_WriteBit(GPIOB, kPinEnable, Bit_RESET);
 	break;
     case U8X8_MSG_BYTE_END_TRANSFER:
@@ -120,7 +113,7 @@ void Display::InitGLib()
     u8g2_Setup_sh1106_128x64_noname_f(&u8g2_, U8G2_R0, u8x8_byte_4wire_hw_spi, u8x8_stm32_gpio_and_delay);
     output_buf = default_buf = u8g2_.tile_buf_ptr;
     u8g2_InitDisplay(&u8g2_);
-    u8g2_SetContrast(&u8g2_, 127);
+    u8g2_SetContrast(&u8g2_, 255);
     u8g2_SetPowerSave(&u8g2_, 0);
 
     Random::Seed(42);

midi2cv/drivers/spi_mode.cc

@@ -0,0 +1,38 @@
+#include "spi_mode.h"
+#include <stm32f37x_conf.h>
+
+uint8_t currentMode = 0;
+
+void InitSPIDisplay(void);
+
+void InitSPI(uint8_t mode)
+{
+    if (currentMode != mode) {
+	switch (mode) {
+	case SPI_MODE_DISPLAY:
+	    InitSPIDisplay();
+	    break;
+	case SPI_MODE_DAC0:
+	case SPI_MODE_DAC1:
+	case SPI_MODE_USB:
+	    break;
+	}
+	currentMode = mode;
+    }
+}
+
+void InitSPIDisplay(void)
+{
+    SPI_InitTypeDef spi_init;
+    spi_init.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
+    spi_init.SPI_Mode = SPI_Mode_Master;
+    spi_init.SPI_DataSize = SPI_DataSize_8b;
+    spi_init.SPI_CPOL = SPI_CPOL_High;
+    spi_init.SPI_CPHA = SPI_CPHA_2Edge;
+    spi_init.SPI_NSS = SPI_NSS_Soft;
+    spi_init.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;
+    spi_init.SPI_FirstBit = SPI_FirstBit_MSB;
+    spi_init.SPI_CRCPolynomial = 7;
+    SPI_Init(SPI2, &spi_init);
+    SPI_Cmd(SPI2, ENABLE);
+}

midi2cv/drivers/spi_mode.h

@@ -0,0 +1,13 @@
+#ifndef MIDI2CV_DRIVERS_SPI_MODE_H
+#define MIDI2CV_DRIVERS_SPI_MODE_H
+
+#include <stm32f37x_conf.h>
+
+#define SPI_MODE_DISPLAY 1
+#define SPI_MODE_DAC0 2
+#define SPI_MODE_DAC1 3
+#define SPI_MODE_USB 4
+
+void InitSPI(uint8_t mode);
+
+#endif

midi2cv/midi2cv.cc

@@ -52,7 +52,7 @@ void TIM2_IRQHandler(void)
 	return;
     }
     TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
-    
+
     // this will get called with 192 kHz (foof)
     // we want to reduce the amount of times the ui gets polled to 1kHz
     // which still is a lot (60fps would be enough tbh)
@@ -63,6 +63,15 @@ void TIM2_IRQHandler(void)
 	ui.Flush();
 	count = 0;
     }
+
+    if (count % 48 == 0) { // write audiodac1
+    }
+    if (count % 48 == 1) { // write audiodac2
+    }
+    if (count % 48 == 2) { // write audiodac3
+    }
+    if (count % 48 == 3) { // write audiodac4
+    }
 }
 }
 
@@ -103,7 +112,7 @@ void Init(void)
     SysTick_Config(F_CPU / 8000);
     IWDG_Enable();
     gpio.Init();
-    asm("bkpt #0");
+    // asm("bkpt #0");
     display.Init();
     InitTimers();
 }
@@ -112,6 +121,8 @@ int main(void)
 {
     Init();
     while (1) {
+	// In this loop we do things that dont depend on any timing, but that have to be done.
+	// you should not write on spi here because that should happen in the TIM2 interrupt
 	ui.Update();
     }
 }