Add files via upload

Author: avandalen

src/avdweb_AnalogReadFast.h

@@ -1,98 +1,96 @@
 /**
- * avdweb_AnalogReadFast.h
- *
- * `avdweb_AnalogReadFast` Library
- * ================================
- *
- * Fast analogRead 10/12 bit ADC for the Arduino Zero and Uno
- *
- * WEBSITE: http://www.avdweb.nl/arduino/libraries/fast-10-bit-adc.html
- *
- * Sources
- * --------
- * https://github.com/avdwebLibraries/avdweb_AnalogReadFast
- *
- * License
- * --------
- * SPDX: MIT
- *
- * `avdweb_AnalogReadFast` - Fast analogRead 10/12 bit ADC for the
- *       Arduino Zero and Uno
- *
- * Copyright (C) 2019-2024 Albert van Dalen <http://www.avdweb.nl>
- * Copyright (C) 2024 Abhijit Bose (aka. Boseji) :contributor:
- *
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the
- * next paragraph) shall be included in all copies or substantial portions
- * of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
- * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- * OTHER DEALINGS IN THE SOFTWARE.
- *
- * Notes
- * ------
- *
- * HISTORY:
- * 1.0.0 7-3-2018 analogReadFast for SAMD21 (10/12bit) and AVR (10bit)
- *
- */
+   avdweb_AnalogReadFast.h
+
+   `avdweb_AnalogReadFast` Library
+   ================================
+
+   Fast analogRead 10/12 bit ADC for the Arduino Zero and Uno
+
+   WEBSITE: http://www.avdweb.nl/arduino/libraries/fast-10-bit-adc.html
+
+   Sources
+   --------
+   https://github.com/avdwebLibraries/avdweb_AnalogReadFast
+
+   License
+   --------
+   SPDX: MIT
+
+   `avdweb_AnalogReadFast` - Fast analogRead 10/12 bit ADC for the
+         Arduino Zero and Uno
+
+   Copyright (C) 2019-2024 Albert van Dalen <http://www.avdweb.nl>
+   Copyright (C) 2024 Abhijit Bose (aka. Boseji) :contributor:
+
+   Permission is hereby granted, free of charge, to any person obtaining
+   a copy of this software and associated documentation files (the "Software"),
+   to deal in the Software without restriction, including without limitation
+   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   and/or sell copies of the Software, and to permit persons to whom the
+   Software is furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice (including the
+   next paragraph) shall be included in all copies or substantial portions
+   of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+   THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+   OTHER DEALINGS IN THE SOFTWARE.
+
+   Notes
+   ------
+
+   HISTORY:
+   1.0.0 7-3-2018 analogReadFast for SAMD21 (10/12bit) and AVR (10bit)
+
+*/
 
 #ifndef analogReadFast_H
 #define analogReadFast_H
 
-// inline library functions must be in header
-int inline analogReadFast(byte ADCpin);
+int inline analogReadFast(byte ADCpin); // inline library functions must be in header
 
 #if defined(__arm__)
 int inline analogReadFast(byte ADCpin)
 {
-    ADC->CTRLA.bit.ENABLE = 0; // disable ADC
-    while (ADC->STATUS.bit.SYNCBUSY == 1)
-        ; // wait for synchronization
+  ADC->CTRLA.bit.ENABLE = 0; // disable ADC
+  while (ADC->STATUS.bit.SYNCBUSY == 1); // wait for synchronization
 
-    int CTRLBoriginal = ADC->CTRLB.reg;
-    int AVGCTRLoriginal = ADC->AVGCTRL.reg;
-    int SAMPCTRLoriginal = ADC->SAMPCTRL.reg;
+  int CTRLBoriginal = ADC->CTRLB.reg;
+  int AVGCTRLoriginal = ADC->AVGCTRL.reg;
+  int SAMPCTRLoriginal = ADC->SAMPCTRL.reg;
 
-    ADC->CTRLB.reg &= 0b1111100011111111; // mask PRESCALER bits
-    ADC->CTRLB.reg |= ADC_CTRLB_PRESCALER_DIV64; // divide Clock by 64
-    ADC->AVGCTRL.reg = ADC_AVGCTRL_SAMPLENUM_1 | // take 1 sample
-        ADC_AVGCTRL_ADJRES(0x00ul); // adjusting result by 0
-    ADC->SAMPCTRL.reg = 0x00; // sampling Time Length = 0
+  ADC->CTRLB.reg &= 0b1111100011111111; // mask PRESCALER bits
+  ADC->CTRLB.reg |= ADC_CTRLB_PRESCALER_DIV64; // divide Clock by 64
+  ADC->AVGCTRL.reg = ADC_AVGCTRL_SAMPLENUM_1 | // take 1 sample
+                     ADC_AVGCTRL_ADJRES(0x00ul); // adjusting result by 0
+  ADC->SAMPCTRL.reg = 0x00; // sampling Time Length = 0
 
-    ADC->CTRLA.bit.ENABLE = 1; // enable ADC
-    while (ADC->STATUS.bit.SYNCBUSY == 1)
-        ; // wait for synchronization
+  ADC->CTRLA.bit.ENABLE = 1; // enable ADC
+  while (ADC->STATUS.bit.SYNCBUSY == 1); // wait for synchronization
 
-    int adc = analogRead(ADCpin);
+  int adc = analogRead(ADCpin);
 
-    ADC->CTRLB.reg = CTRLBoriginal;
-    ADC->AVGCTRL.reg = AVGCTRLoriginal;
-    ADC->SAMPCTRL.reg = SAMPCTRLoriginal;
+  ADC->CTRLB.reg = CTRLBoriginal;
+  ADC->AVGCTRL.reg = AVGCTRLoriginal;
+  ADC->SAMPCTRL.reg = SAMPCTRLoriginal;
 
-    return adc;
+  return adc;
 }
 #else
+
 int inline analogReadFast(byte ADCpin)
-{
-    byte ADCSRAoriginal = ADCSRA;
-    ADCSRA = (ADCSRA & B11111000) | 4;
-    int adc = analogRead(ADCpin); // Initialize variable and burn a read
-    adc = analogRead(ADCpin); // because ADMUX takes 2.5us to switch
-    ADCSRA = ADCSRAoriginal;
-    return adc;
+{ byte ADCSRAoriginal = ADCSRA; // Save original settings
+  ADCSRA = (ADCSRA & B11111000) | 4; // Reduce ADC clock prescaler for faster reading
+  int adc = analogRead(ADCpin); // Dummy analog read to stabilize
+  adc = analogRead(ADCpin);
+  ADCSRA = ADCSRAoriginal; // Restore original settings
+  return adc;
 }
+
 #endif
 #endif /* analogReadFast_H */