How to interrupt continuous ADC regular channel conversion using ADC injected
channels, and how to get the result of this conversion.
The ADC3 is configured to convert continuously regular ADC_CHANNEL_10
and convert injected ADC_CHANNEL_12 (connected to PC.02) when injected conversion starts
(after one second of the start of regular channel).
Each time a regular channel end of conversion occurs an interrupt is generated
and the converted data of ADC3 DR register is affected to the uhADCxConvertedRegValue
variable in the ADC conversion complete callback function. After one second of
the start of regular ADC_CHANNEL_10 conversion the injected ADC_CHANNEL_12 conversion starts
so regular conversion is temporary interrupted until the end of injected conversion.
When the injected conversion is finished, an interrupt is generated, and the
converted injected data of ADC3 DR register is affected to the uhADCxConvertedInjValue
variable in the ADC conversion complete callback function.
Conversion time (reference manual, Reset and Clock control part):
The function SystemClock_Config() configures the clock divider as follows:
1) The system clock is 180 MHz.
2) AHB Prescaler = 1 => AHB clock is 180 MHz.
2) APB2 Prescaler = 2 => APB2 clock is 90 MHz.
3) ADC Prescaler = 4 => ADC clock is 22.5 MHz.
Sampling time is set to ADC_SAMPLETIME_56CYCLES (56 cycles).
ConvTime = Sampling time + 12 cycles ADC conversion time + 3 cycles sampling time.
= 71 clock cycles
= 3.2 us
User can vary the ADC_CHANNEL_10 voltage using the Eval Board potentiometer (RV1) connected to PC.0.
The converted values could be monitered through a debugger:
- uhADCxConvertedRegValue for regular conversion
- uhADCxConvertedInjValue for injected conversion
STM32 Eval board's LEDs can be used to monitor the transfer status:
- LED3 is ON when there is an initialization error.
@note The connection of the LCD reset pin to a dedicated GPIO PK7 instead of the STM32F469 NRST pin may cause residual display on LCD with applications/examples that do not require display.
The LCD clear can be ensured by hardware through the board's power off/power on or by software calling the BSP_LCD_Reset() function.
