analog-read
xod/gpio/analog-read
Reads analog signal value from board ADC port.
Possible errors:
— Invalid port
analog-read
@/analog-read
Reads analog signal value from board ADC port.
Possible errors:
— Invalid port
PORTport
Analog port to read from. Should start with `A` to succeed.
UPDpulse
Triggers new read
DONEpulse
Fires on reading complete
VALnumber
The latest read value in range 0.0 … 1.0
Previously known as xod/core/analog-input.
C++ implementation
#pragma XOD evaluate_on_pin disable
#pragma XOD evaluate_on_pin enable input_UPD
node {
// reading from analog input too frequently may affect WiFi connection on ESP8266
// see https://github.com/krzychb/EspScopeA0/tree/master/Bravo#results
#ifdef ESP8266
TimeMs lastReadTime = 0;
#endif
void evaluate(Context ctx) {
static_assert(isValidAnalogPort(constant_input_PORT), "must be a valid analog port");
if (!isInputDirty<input_UPD>(ctx))
return;
::pinMode(constant_input_PORT, INPUT);
#ifdef ESP8266
if (transactionTime() - lastReadTime > 4) {
lastReadTime = transactionTime();
emitValue<output_VAL>(ctx, ::analogRead(constant_input_PORT) / 1023.);
}
#else
emitValue<output_VAL>(ctx, ::analogRead(constant_input_PORT) / 1023.);
#endif
emitValue<output_DONE>(ctx, 1);
}
}