Use PWM for contrast control on PB9

STM32F407VGTx.ioc

@@ -2,40 +2,47 @@
 File.Version=5
 KeepUserPlacement=true
 Mcu.Family=STM32F4
-Mcu.IP0=DAC
-Mcu.IP1=NVIC
-Mcu.IP2=RCC
-Mcu.IP3=TIM7
+Mcu.IP0=NVIC
+Mcu.IP1=RCC
+Mcu.IP2=TIM7
+Mcu.IP3=TIM11
 Mcu.IP4=TIM12
 Mcu.IPNb=5
 Mcu.Name=STM32F407V(E-G)Tx
 Mcu.Package=LQFP100
 Mcu.Pin0=PH0-OSC_IN
 Mcu.Pin1=PH1-OSC_OUT
-Mcu.Pin10=PB15
+Mcu.Pin10=PB9
 Mcu.Pin11=VP_TIM7_VS_ClockSourceINT
-Mcu.Pin2=PA5
-Mcu.Pin3=PE7
-Mcu.Pin4=PE8
-Mcu.Pin5=PE9
-Mcu.Pin6=PE10
-Mcu.Pin7=PE11
-Mcu.Pin8=PE12
-Mcu.Pin9=PE13
-Mcu.PinsNb=12
+Mcu.Pin12=VP_TIM11_VS_ClockSourceINT
+Mcu.Pin2=PE7
+Mcu.Pin3=PE8
+Mcu.Pin4=PE9
+Mcu.Pin5=PE10
+Mcu.Pin6=PE11
+Mcu.Pin7=PE12
+Mcu.Pin8=PE13
+Mcu.Pin9=PB15
+Mcu.PinsNb=13
 Mcu.UserConstants=
 Mcu.UserName=STM32F407VGTx
 MxCube.Version=4.9.0
 MxDb.Version=DB.4.0.90
 NVIC.PriorityGroup=NVIC_PRIORITYGROUP_0
 NVIC.SysTick_IRQn=true\:0\:0\:false
-PA5.GPIOParameters=GPIO_Label
-PA5.GPIO_Label=LCD_VO
-PA5.Locked=true
-PA5.Signal=COMP_DAC2_group
-PB15.GPIOParameters=GPIO_Label
+NVIC.TIM7_IRQn=true\:0\:6\:false
+PB15.GPIOParameters=GPIO_ModeDefaultPP,GPIO_Speed,GPIO_PuPd,GPIO_Label
 PB15.GPIO_Label=LCD_K
+PB15.GPIO_ModeDefaultPP=GPIO_MODE_AF_PP
+PB15.GPIO_PuPd=GPIO_NOPULL
+PB15.GPIO_Speed=GPIO_SPEED_LOW
 PB15.Signal=S_TIM12_CH2
+PB9.GPIOParameters=GPIO_ModeDefaultPP,GPIO_Speed,GPIO_PuPd,GPIO_Label
+PB9.GPIO_Label=LCD_VO
+PB9.GPIO_ModeDefaultPP=GPIO_MODE_AF_PP
+PB9.GPIO_PuPd=GPIO_NOPULL
+PB9.GPIO_Speed=GPIO_SPEED_MEDIUM
+PB9.Signal=S_TIM11_CH1
 PCC.Checker=false
 PCC.Line=STM32F407/417
 PCC.MCU=STM32F407V(E-G)Tx
@@ -45,32 +52,53 @@ PCC.Seq0=0
 PCC.Series=STM32F4
 PCC.Temperature=25
 PCC.Vdd=3.3
-PE10.GPIOParameters=GPIO_Label
+PE10.GPIOParameters=GPIO_Speed,GPIO_PuPd,GPIO_Label,GPIO_ModeDefaultOutputPP
 PE10.GPIO_Label=LCD_DB4
+PE10.GPIO_ModeDefaultOutputPP=GPIO_MODE_OUTPUT_PP
+PE10.GPIO_PuPd=GPIO_NOPULL
+PE10.GPIO_Speed=GPIO_SPEED_LOW
 PE10.Locked=true
 PE10.Signal=GPIO_Output
-PE11.GPIOParameters=GPIO_Label
+PE11.GPIOParameters=GPIO_Speed,GPIO_PuPd,GPIO_Label,GPIO_ModeDefaultOutputPP
 PE11.GPIO_Label=LCD_DB5
+PE11.GPIO_ModeDefaultOutputPP=GPIO_MODE_OUTPUT_PP
+PE11.GPIO_PuPd=GPIO_NOPULL
+PE11.GPIO_Speed=GPIO_SPEED_LOW
 PE11.Locked=true
 PE11.Signal=GPIO_Output
-PE12.GPIOParameters=GPIO_Label
+PE12.GPIOParameters=GPIO_Speed,GPIO_PuPd,GPIO_Label,GPIO_ModeDefaultOutputPP
 PE12.GPIO_Label=LCD_DB6
+PE12.GPIO_ModeDefaultOutputPP=GPIO_MODE_OUTPUT_PP
+PE12.GPIO_PuPd=GPIO_NOPULL
+PE12.GPIO_Speed=GPIO_SPEED_LOW
 PE12.Locked=true
 PE12.Signal=GPIO_Output
-PE13.GPIOParameters=GPIO_Label
+PE13.GPIOParameters=GPIO_Speed,GPIO_PuPd,GPIO_Label,GPIO_ModeDefaultOutputPP
 PE13.GPIO_Label=LCD_DB7
+PE13.GPIO_ModeDefaultOutputPP=GPIO_MODE_OUTPUT_PP
+PE13.GPIO_PuPd=GPIO_NOPULL
+PE13.GPIO_Speed=GPIO_SPEED_LOW
 PE13.Locked=true
 PE13.Signal=GPIO_Output
-PE7.GPIOParameters=GPIO_Label
+PE7.GPIOParameters=GPIO_Speed,GPIO_PuPd,GPIO_Label,GPIO_ModeDefaultOutputPP
 PE7.GPIO_Label=LCD_RS
+PE7.GPIO_ModeDefaultOutputPP=GPIO_MODE_OUTPUT_PP
+PE7.GPIO_PuPd=GPIO_NOPULL
+PE7.GPIO_Speed=GPIO_SPEED_LOW
 PE7.Locked=true
 PE7.Signal=GPIO_Output
-PE8.GPIOParameters=GPIO_Label
+PE8.GPIOParameters=GPIO_Speed,GPIO_PuPd,GPIO_Label,GPIO_ModeDefaultOutputPP
 PE8.GPIO_Label=LCD_RW
+PE8.GPIO_ModeDefaultOutputPP=GPIO_MODE_OUTPUT_PP
+PE8.GPIO_PuPd=GPIO_NOPULL
+PE8.GPIO_Speed=GPIO_SPEED_LOW
 PE8.Locked=true
 PE8.Signal=GPIO_Output
-PE9.GPIOParameters=GPIO_Label
+PE9.GPIOParameters=GPIO_Speed,GPIO_PuPd,GPIO_Label,GPIO_ModeDefaultOutputPP
 PE9.GPIO_Label=LCD_E
+PE9.GPIO_ModeDefaultOutputPP=GPIO_MODE_OUTPUT_PP
+PE9.GPIO_PuPd=GPIO_NOPULL
+PE9.GPIO_Speed=GPIO_SPEED_LOW
 PE9.Locked=true
 PE9.Signal=GPIO_Output
 PH0-OSC_IN.Mode=HSE-External-Oscillator
@@ -110,12 +138,14 @@ RCC.VCOI2SOutputFreq_Value=192000000
 RCC.VCOInputFreq_Value=1000000
 RCC.VCOOutputFreq_Value=336000000
 RCC.VcooutputI2S=96000000
-SH.COMP_DAC2_group.0=DAC_OUT2,DAC_OUT2
-SH.COMP_DAC2_group.ConfNb=1
+SH.S_TIM11_CH1.0=TIM11_CH1,PWM Generation1 CH1
+SH.S_TIM11_CH1.ConfNb=1
 SH.S_TIM12_CH2.0=TIM12_CH2,PWM Generation2 CH2
 SH.S_TIM12_CH2.ConfNb=1
 TIM12.Channel-PWM\ Generation2\ CH2=TIM_CHANNEL_2
 TIM12.IPParameters=Channel-PWM Generation2 CH2
+VP_TIM11_VS_ClockSourceINT.Mode=Enable_Timer
+VP_TIM11_VS_ClockSourceINT.Signal=TIM11_VS_ClockSourceINT
 VP_TIM7_VS_ClockSourceINT.Mode=Enable_Timer
 VP_TIM7_VS_ClockSourceINT.Signal=TIM7_VS_ClockSourceINT
 board=STM32F4DISCOVERY

src/hd44780/hd44780.c

@@ -28,24 +28,31 @@
 #include "hd44780.h"
 #include "stm32f4xx.h"
 
+#define BKL_FREQ			125000
+#define CON_FREQ			250000
+
 #define HD44780_TIMER 		TIM7
 #define HD44780_PRIORITY 	6
 
 #define BKL_TIMER 			TIM12
 #define BKL_CHANNEL			TIM_CHANNEL_2
 
 #define BKL_TIME			1000
-#define BKL_FREQ			125000
 #define BKL_PERIOD			(SystemCoreClock / 2) / BKL_FREQ
 
 #define BKL_GPIO			GPIOB
 #define BKL_PIN				GPIO_PIN_15
 #define BKL_AF 				GPIO_AF9_TIM12
 
-#define CON_CHANNEL			DAC_CHANNEL_2
+#define CON_GPIO_EN			__GPIOB_CLK_ENABLE
+#define CON_GPIO			GPIOB
+#define CON_PIN				GPIO_PIN_9
+#define CON_AF 				GPIO_AF3_TIM11
+#define CON_TIMER 			TIM11
+#define CON_CHANNEL			TIM_CHANNEL_1
+#define CON_CLK_EN			__TIM11_CLK_ENABLE
+#define CON_PERIOD			HAL_RCC_GetHCLKFreq() / CON_FREQ
 
-#define CON_GPIO			GPIOA
-#define CON_PIN				GPIO_PIN_5
 
 #define MAX_CONTRAST		3000
 
@@ -93,8 +100,8 @@ typedef struct {
 } hd44780_conf_t;
 
 static TIM_HandleTypeDef TIM_Handle_Lcd;
-TIM_HandleTypeDef TIM_Handle_Brigt;
-DAC_HandleTypeDef DAC_Handle_Cont;
+static TIM_HandleTypeDef TIM_Handle_Brigt;
+static TIM_HandleTypeDef Handle_Con;
 
 static hd44780_conf_t Lcd_Conf;
 static volatile hd44780_task_t Queue[HD44780_QUEUE_SIZE];
@@ -269,10 +276,12 @@ void hd44780_brightness(const uint8_t brightness) {
  */
 void hd44780_contrast(const uint8_t contrast) {
 
-	uint16_t cont;
+	uint32_t cont;
 
-	cont = ((uint32_t) (100 - contrast) * MAX_CONTRAST) / 100;
-	HAL_DAC_SetValue(&DAC_Handle_Cont, CON_CHANNEL, DAC_ALIGN_12B_R, cont);
+	cont = (uint32_t) (100 - contrast);
+	cont *= BKL_PERIOD * 2;
+	cont /= 100;
+	__HAL_TIM_SetCompare(&Handle_Con, CON_CHANNEL, cont);
 }
 
 /**
@@ -542,23 +551,35 @@ void hd44780_init_brightness(void) {
  */
 void hd44780_init_contrast(void) {
 
-	GPIO_InitTypeDef GPIO_InitStructure;
-	DAC_ChannelConfTypeDef DAC_ChannelConf;
-
-	__GPIOA_CLK_ENABLE();
-	GPIO_InitStructure.Pin = CON_PIN;
-	GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
-	GPIO_InitStructure.Pull = GPIO_NOPULL;
-	HAL_GPIO_Init(CON_GPIO, &GPIO_InitStructure);
-
-	__DAC_CLK_ENABLE();
-	DAC_Handle_Cont.Instance = DAC;
-	HAL_DAC_Init(&DAC_Handle_Cont);
-
-	DAC_ChannelConf.DAC_Trigger = DAC_TRIGGER_NONE;
-	DAC_ChannelConf.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
-	HAL_DAC_ConfigChannel(&DAC_Handle_Cont, &DAC_ChannelConf, CON_CHANNEL);
-	HAL_DAC_Start(&DAC_Handle_Cont, CON_CHANNEL);
+	GPIO_InitTypeDef gpio;
+	TIM_OC_InitTypeDef oc;
+
+	CON_GPIO_EN();
+	gpio.Pin = CON_PIN;
+	gpio.Mode = GPIO_MODE_AF_OD;
+	gpio.Pull = GPIO_PULLDOWN;
+	gpio.Speed = GPIO_SPEED_MEDIUM;
+	gpio.Alternate = CON_AF;
+	HAL_GPIO_Init(CON_GPIO, &gpio);
+
+	CON_CLK_EN();
+	Handle_Con.Instance = CON_TIMER;
+	Handle_Con.Init.Period = CON_PERIOD;
+	Handle_Con.Init.Prescaler = 1 - 1;
+	Handle_Con.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
+	Handle_Con.Init.CounterMode = TIM_COUNTERMODE_UP;
+	HAL_TIM_PWM_Init(&Handle_Con);
+
+	oc.OCMode = TIM_OCMODE_PWM1;
+	oc.OCIdleState = TIM_OCIDLESTATE_SET;
+	oc.OCNIdleState = TIM_OCNIDLESTATE_RESET;
+	oc.Pulse = 0;
+	oc.OCPolarity = TIM_OCPOLARITY_HIGH;
+	oc.OCNPolarity = TIM_OCNPOLARITY_HIGH;
+
+	HAL_TIM_PWM_ConfigChannel(&Handle_Con, &oc,
+	CON_CHANNEL);
+	HAL_TIM_PWM_Start(&Handle_Con, CON_CHANNEL);
 }
 
 void TIM7_IRQHandler(void) {