Hallo,
ich würde gerne einen Filter in den "normalen" Arduino Sketch implimentieren. Hier würde ich gerne folgenden nutzen:
struct butterworthFilter_t
{
float v[2];
float result;
};
void MAX30100::lowPassButterworthFilter( float x, butterworthFilter_t * filterResult )
{
filterResult->v[0] = filterResult->v[1];
//Fs = 100Hz and Fc = 10Hz
filterResult->v[1] = (2.452372752527856026e-1 * x) + (0.50952544949442879485 * filterResult->v[0]);
//Fs = 100Hz and Fc = 4Hz
//filterResult->v[1] = (1.367287359973195227e-1 * x) + (0.72654252800536101020 * filterResult->v[0]); //Very precise butterworth filter
filterResult->result = filterResult->v[0] + filterResult->v[1];
}
Meinen Sketch habe ich wie folgt aufgebaut:
/*!
* @file basicRead.ino
* @brief Output readings of red light and IR
* @n This library supports mainboards: ESP8266, FireBeetle-M0, UNO, ESP32, Leonardo, Mega2560
* @copyright Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
* @licence The MIT License (MIT)
* @author [YeHangYu](hangyu.ye@dfrobot.com)
* @version V0.1
* @date 2020-05-29
* @url https://github.com/DFRobot/DFRobot_MAX30102
*/
#include <DFRobot_MAX30102.h>
float x;
float v[2];
float result;
float filterResult;
float Filter_Wert;
DFRobot_MAX30102 particleSensor;
/*
Macro definition opions in sensor configuration
sampleAverage: SAMPLEAVG_1 SAMPLEAVG_2 SAMPLEAVG_4
SAMPLEAVG_8 SAMPLEAVG_16 SAMPLEAVG_32
ledMode: MODE_REDONLY MODE_RED_IR MODE_MULTILED
sampleRate: PULSEWIDTH_69 PULSEWIDTH_118 PULSEWIDTH_215 PULSEWIDTH_411
pulseWidth: SAMPLERATE_50 SAMPLERATE_100 SAMPLERATE_200 SAMPLERATE_400
SAMPLERATE_800 SAMPLERATE_1000 SAMPLERATE_1600 SAMPLERATE_3200
adcRange: ADCRANGE_2048 ADCRANGE_4096 ADCRANGE_8192 ADCRANGE_16384
*/
void setup()
{
//Init serial
Serial.begin(115200);
/*!
*@brief Init sensor
*@param pWire IIC bus pointer object and construction device, can both pass or not pass parameters (Wire in default)
*@param i2cAddr Chip IIC address (0x57 in default)
*@return true or false
*/
while (!particleSensor.begin()) {
Serial.println("MAX30102 was not found");
delay(1000);
}
/*!
*@brief Use macro definition to configure sensor
*@param ledBrightness LED brightness, default value: 0x1F（6.4mA), Range: 0~255（0=Off, 255=50mA）
*@param sampleAverage Average multiple samples then draw once, reduce data throughput, default 4 samples average
*@param ledMode LED mode, default to use red light and IR at the same time
*@param sampleRate Sampling rate, default 400 samples every second
*@param pulseWidth Pulse width: the longer the pulse width, the wider the detection range. Default to be Max range
*@param adcRange Measurement Range, default 4096 (nA), 15.63(pA) per LSB
*/
particleSensor.sensorConfiguration(/*ledBrightness=*/0x1F, /*sampleAverage=*/SAMPLEAVG_4, \
/*ledMode=*/MODE_MULTILED, /*sampleRate=*/SAMPLERATE_400, \
/*pulseWidth=*/PULSEWIDTH_411, /*adcRange=*/ADCRANGE_4096);
}
void loop()
{
//Print result
Serial.print("R=");
/*!
*@brief Get red value
*@return Red light reading
*/
Serial.print(particleSensor.getRed());
Serial.print(" IR=");
/*!
*@brief Get IR value
*@return IR reading
*/
Serial.print(particleSensor.getIR());
Serial.println();
delay(100);
// Filter //
filterResult->v[0] = filterResult->v[1];
//Fs = 100Hz and Fc = 10Hz
filterResult->v[1] = (2.452372752527856026e-1 * x) + (0.50952544949442879485 * filterResult->v[0]);
//Fs = 100Hz and Fc = 4Hz
//filterResult->v[1] = (1.367287359973195227e-1 * x) + (0.72654252800536101020 * filterResult->v[0]); //Very precise butterworth filter
filterResult->result = filterResult->v[0] + filterResult->v[1];
Filter_Wert = (v[2] + result)* filterResult;
}
Hier ist mir aber ein Fehler unterlaufen und ich bekomme folgende Fehlermeldung:
:\Users\emanu\AppData\Local\Temp.arduinoIDE-unsaved202333-19788-15329bg.c41kl\basicRead\basicRead.ino:83:36: error: base operand of '->' is not a pointer
filterResult->v[0] = filterResult->v[1];
Wenn ich das korrekt verstehe muss ich innerhalb einer structur (oder Funktion?) einen "pointer" verwenden wie bspw " .prev". Der Befehl -> weißt dann eine Funktion oder einen Wert einer anderen Variable zu, korrekt? Der ganze Code aus dem ich den Filter habe findet sich hier: xcoder123/MAX30100: Driver for MAX30100 using arduino (github.com)
