Question
ADC Scan Mode and PWM Complementary Channel Conflict.
(MCU:STM8AF6223A-TSSOP20 MCU Label: STM8AF6223PDX
Library: SPL V2.2.0
Compiler SDCC:4.5.0 Debugger:stm8-gdb 8.1
Custom Makefile
MCU uses internal oscillator runnnig 16 MHz)
Hi I'm Attila.
When I enable the ADC1 Scan Mode and DataBuffer with ADC_Channel >= ADC1_CHANNEL_2 TIM1_CH2N waveform distorted.
Oscilloscope CH1(Yellow) -> TIM1_CH1N
Oscilloscope CH1(Light Blue) -> TIM1_CH2N
For example when ADC_Init() with ADC1_CHANNEL_2
when ADC_Init() with ADC1_CHANNEL_1
ADC1_CHANNEL_2 is the AIN2 but Before the operation, i program the option bytes for enable the complementary channels.
What causes the distortion?
Best regards.
Bonus.
I also try disable TIM1_CH2N with TIM1_OC2Init() function i realized that ADC sampling effect that pin .
Some piece of code
void main(void)
{
CLK_HSIPrescalerConfig(CLK_PRESCALER_HSIDIV1);
ADC_Config();
TIM1_Config();
ITC_SetSoftwarePriority(ITC_IRQ_ADC1, ITC_PRIORITYLEVEL_2);
TIM1_Cmd(ENABLE);
TIM1_CtrlPWMOutputs(ENABLE);
TIM1_SetCompare1(66);
TIM1_SetCompare2(376);
TIM1_SetCompare3(1);
}
static void ADC_Config()
{
/* Init GPIO for ADC1 */
GPIO_Init(GPIOD, GPIO_PIN_2, GPIO_MODE_IN_FL_NO_IT);
GPIO_Init(GPIOD, GPIO_PIN_3, GPIO_MODE_IN_FL_NO_IT); //20.pin for reading negative current
/* De-Init ADC peripheral*/
ADC1_DeInit();
/* Init ADC2 peripheral */
ADC1_Init(ADC1_CONVERSIONMODE_SINGLE/*ADC1_CONVERSIONMODE_CONTINUOUS*/, ADC1_CHANNEL_2, ADC1_PRESSEL_FCPU_D2,
ADC1_EXTTRIG_TIM, /*DISABLE*/ENABLE, ADC1_ALIGN_RIGHT, ADC1_SCHMITTTRIG_ALL,
DISABLE);
/* Enable scan mode and buffering */
ADC1_ScanModeCmd(ENABLE);
ADC1_DataBufferCmd(ENABLE);
/* Enable EOC interrupt */
ADC1_ITConfig(ADC1_IT_EOCIE, ENABLE); // not ADC1_IT_EOC
ADC1_Cmd(ENABLE);
ADC1_SchmittTriggerConfig(ADC1_SCHMITTTRIG_ALL, DISABLE); // explicitly disable Schmitt on AIN2 = PC4
ADC1_StartConversion();
}
static void TIM1_Config(void)
{
TIM1_DeInit();
CLK_PeripheralClockConfig(CLK_PERIPHERAL_TIMER1, ENABLE);
GPIO_Init(GPIOC, GPIO_PIN_6, GPIO_MODE_OUT_PP_HIGH_FAST); // CH1
GPIO_Init(GPIOC, GPIO_PIN_3, GPIO_MODE_OUT_PP_LOW_FAST); // CH1N
GPIO_Init(GPIOC, GPIO_PIN_7, GPIO_MODE_OUT_PP_HIGH_FAST); // CH2
GPIO_Init(GPIOC, GPIO_PIN_4, GPIO_MODE_OUT_PP_LOW_FAST); // CH2N
TIM1_TimeBaseInit(0, COUNTER_MODE, TIM_PERIOD, PWM_REPETITION_COUNTER);
TIM1_OC1Init(
TIM1_OCMODE_PWM2,
TIM1_OUTPUTSTATE_ENABLE,
TIM1_OUTPUTNSTATE_ENABLE,
0, // CCR2
TIM1_OCPOLARITY_HIGH,
TIM1_OCNPOLARITY_HIGH,
TIM1_OCIDLESTATE_RESET,
TIM1_OCNIDLESTATE_SET
);
TIM1_OC1PreloadConfig(ENABLE);
TIM1_OC2Init(
TIM1_OCMODE_PWM2,
TIM1_OUTPUTSTATE_ENABLE,
TIM1_OUTPUTNSTATE_ENABLE,
0, // CCR2
TIM1_OCPOLARITY_HIGH,
TIM1_OCNPOLARITY_HIGH,
TIM1_OCIDLESTATE_RESET,
TIM1_OCNIDLESTATE_SET
);
TIM1_OC2PreloadConfig(ENABLE);
TIM1_OC3Init(TIM1_OCMODE_PWM1, TIM1_OUTPUTSTATE_DISABLE, TIM1_OUTPUTNSTATE_DISABLE, (uint16_t)1, TIM1_OCPOLARITY_HIGH, TIM1_OCNPOLARITY_HIGH, TIM1_OCIDLESTATE_RESET, TIM1_OCNIDLESTATE_RESET);
TIM1_OC3PreloadConfig(ENABLE);
TIM1_BDTRConfig(
TIM1_OSSISTATE_DISABLE, // OSSI (off-state selection for idle mode)
TIM1_LOCKLEVEL_1,
8, // Deadtime
TIM1_BREAK_DISABLE, // Break enable
TIM1_BREAKPOLARITY_LOW, // Break polarity
TIM1_AUTOMATICOUTPUT_ENABLE // Automatic output enable
);
TIM1_SelectOutputTrigger(TIM1_TRGOSOURCE_OC3REF);
}
INTERRUPT_HANDLER(ADC1_IRQHandler, 22)
{
if (ADC1_GetFlagStatus(ADC1_FLAG_EOC) == SET)
{
value_pos = ADC1_GetBufferValue(3); // AIN3 (positive current)
value_neg = ADC1_GetBufferValue(4); // AIN4 (negative current)
adc_sample_counter += 1u;
ADC1_ClearFlag(ADC1_FLAG_EOC);
if (ADC1_GetFlagStatus(ADC1_FLAG_OVR) == SET) {
ADC1_ClearFlag(ADC1_FLAG_OVR); // Handle potential overrun
}
}
}