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Analogue

ADC (mwx::periph_analogue.hpp)

Analogue performs ADC and acquires values. It can continuously acquire multiple channels at a time, and can do so sequentially according to a timer or other cycle.

Constant.

Pin Definition.

constant

classification

Pin name in standard apps

In the standard application (App_Twelite), the pin names ADC2/ADC3 in the semiconductor data sheet are AI3/AI2 to match the TWELITE DIP. Please note this.

*1 ADC2/ADC3 pins for both digital and analog are subject to usage procedures and restrictions.

Assume no pull-up on the pin to be used before the ADC starts. If this is not done, the pull-up voltage will always be observed in the ADC.

pinMode(PIN_DIGITAL::DIO0, PIN_MODE::INPUT); 
pinMode(PIN_DIGITAL::DIO1, PIN_MODE::INPUT);

In a normal circuit configuration, current leakage occurs during sleep. It cannot be circumvented by software description alone.

To avoid current leakage during sleep, the GND of the analog circuit section should be disconnected with a FET switch or the like and left floating during sleep. Also, before sleep, set the pin to input and pull-up state.

method.

setup()

void setup(
        bool bWaitInit = false,
        uint8_t kick_ev = E_AHI_DEVICE_TICK_TIMER,
        void (*fp_on_finish)() = nullptr)

Initializes ADCs. setup() starts the regulator inside the semiconductor, specifies the timer device for periodic execution, and specifies the callback function to be called when all ADCs on the specified channel have completed.

begin()

void begin(uint8_t bmPorts, uint8_t capt_tick = 1)

The first parameter specifies the port where the ADC is to be made. The port specification is a bitmap with the bits set corresponding to the port numbers mentioned in the pin definition.For example, if you want to get the values of two pins PIN_ANALOGUE::A2 and PIN_ANALOGUE::VCC, specify (1 <<PIN_ANALOGUE::A1 | 1<<PIN_ANALOGUE::VCC ). You can also use pack_bits and write pack_bits(PIN_ANALOGUE::A1,PIN_ANALOGUE::VCC).

After calling begin(), the first ADC processing starts immediately, and the processing of the next pin starts from its end interrupt. When all processing is finished (if specified), the callback function is called. It waits until the next timer interrupt occurs before starting a new ADC process.

The second parameter specifies the number of timer interrupts before AC starts. For example, TickTimer is called every 1 ms, but if you specify 16 for the parameter, it will be processed every 16 ms.

void begin()

Starts ADC processing with default ADC pins (PIN_ANALOGUE::A1, PIN_ANALOGUE::A2). end() resumes the interrupted ADC processing.

end()

void end()

ADC processing is terminated and the regulator inside the semiconductor is stopped.

available()

inline bool available()

The value of the ADC is set to true after the acquisition. After confirmation by this function, it is false until the next ADC completion.

read(), read_raw()

inline int16_t read(uint8_t s)
inline int16_t read_raw(uint8_t s)

Reads ADC values. The parameter specifies the ADC pin to be read. read() returns the read value converted to mV and read_raw() returns the ADC value (0..1023).

It is recommended to read Vcc with read(). This is because a special conversion formula must be applied to convert from read_raw() values to mV.

After ADC completion (available), if the value is read after a delay until near the timing when the next ADC process is executed, the next ADC value may be returned, because the ADC process is executed by an interrupt handler and the value is updated even during the loop() process.

ADC interrupt handler.

The ADC interrupt handler is set to periph_analogue::ADC_handler() when setup() is called.

If a different handler is specified by the semiconductor peripheral library, it will not work properly.

Sleep behavior

If the ADC is in cyclic execution state by begin(), ADC processing is resumed after returning from sleep.