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authorYves Fischer <yvesf-git@xapek.org>2011-10-11 21:50:49 +0200
committerYves Fischer <yvesf-git@xapek.org>2011-10-11 21:50:49 +0200
commit324c5ba9098c1010d0aa8c1e26b95509878ce9f2 (patch)
treef6ef2d537decaa2e1af6d4b9c4c31161b22333ec /firmware/adc.c
downloadmini-octopus-324c5ba9098c1010d0aa8c1e26b95509878ce9f2.tar.gz
mini-octopus-324c5ba9098c1010d0aa8c1e26b95509878ce9f2.zip
Mini-Octopus build from r@171
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+/*
+ * Copyright (c) 2007 empronix (http://www.empronix.com)
+ * Author: Benedikt Sauter <sauter@empronix.com>
+ * All rights reserved.
+ *
+ * Short descripton of file:
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ * * Neither the name of the FH Augsburg nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES{} LOSS OF USE,
+ * DATA, OR PROFITS{} OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "common.h"
+#include "protocol.h"
+#include "adc.h"
+
+void adc_parser(char *buf)
+{
+ switch(buf[0])
+ {
+ case CMD_ADC_INIT_PIN:
+ adc_init_usb((int)buf[2]);
+ break;
+ case CMD_ADC_GET:
+ adc_get_usb((int)buf[2]);
+ break;
+ case CMD_ADC_REF:
+ adc_ref_usb((int)buf[2]);
+ break;
+
+ default:
+ answer[0]=buf[0];
+ answer[1]=RSP_UNKOWN_CMD;
+ answer[2]=0;
+ CommandAnswer(3);
+ }
+}
+
+int adc_init(int pin)
+{
+ if (pin >= 33 && pin <= 40)
+ {
+ octopus.ports[pin] = PIN_AD;
+
+ switch(pin)
+ {
+ case 40: break;
+ case 39: break;
+ case 38: break;
+ case 37: break;
+ case 36: break;
+ case 35: break;
+ case 34: break;
+ case 33: break;
+ default:
+ return RSP_IMPOSSIBLE_PIN_CONFIG;
+ }
+ return RSP_OK;
+ }
+ return RSP_UNKOWN_PIN;
+}
+
+void adc_init_usb(int pin)
+{
+ answer[0]=CMD_ADC_INIT_PIN;
+ answer[1]= (unsigned char)adc_init(pin);
+ answer[2]=0;
+
+ CommandAnswer(3);
+}
+
+void adc_get_usb(int pin)
+{
+
+ uint16_t result;
+ //uint8_t result[2];
+
+ answer[0]=CMD_ADC_GET;
+ answer[1]=adc_get(pin,&result);
+ //result[0] = 0x77;
+ //result[1] = 0x88;
+ //answer[2]=(char)result[1]; //high
+ //answer[3]=(char)result[0]; //low
+ answer[2]=(char)(result>>8); //high
+ answer[3]=(char)(result); //low
+ CommandAnswer(4);
+}
+
+
+int adc_get(int pin, uint16_t *value)
+{
+ *value = 0;
+
+ if (octopus.ports[pin] == PIN_AD)
+ {
+ switch (pin)
+ {
+ case 40: *value =_adc_read_channel(0); break;
+ case 39: *value =_adc_read_channel(1); break;
+ case 38: *value =_adc_read_channel(2); break;
+ case 37: *value =_adc_read_channel(3); break;
+ case 36: *value =_adc_read_channel(4); break;
+ case 35: *value =_adc_read_channel(5); break;
+ case 34: *value =_adc_read_channel(6); break;
+ case 33: *value =_adc_read_channel(7); break;
+ default:
+ return RSP_IMPOSSIBLE_PIN_CONFIG;
+ }
+ return RSP_OK;
+ }
+ else
+ {
+ return RSP_WRONG_PIN_CONFIG;
+ }
+}
+
+void adc_ref_usb(int ref)
+{
+ answer[0]=CMD_ADC_REF;
+ answer[1]=adc_ref(ref);
+ CommandAnswer(2);
+}
+
+int adc_ref(int ref)
+{
+ ADMUX = 0x00;
+
+ switch(ref){
+ case PARAM_ADC_AREF: break;
+ case PARAM_ADC_AVCC: ADMUX |= (1<<REFS0); break;
+ case PARAM_ADC_INTERNAL: ADMUX |= (1<<REFS1) | (1<<REFS0); break;
+ default:
+ return RSP_ERROR;
+ }
+ return RSP_OK;
+}
+
+uint16_t _adc_read_channel(int mux)
+{
+ int i;
+ uint16_t result;
+
+ ADCSRA = (1<<ADEN) | (1<<ADPS1) | (1<<ADPS0); // Frequenzvorteiler
+ // setzen auf 8 (1) und ADC aktivieren (1)
+
+ //ADMUX |= (unsigned char)mux; // Kanal waehlen
+ ADMUX = (ADMUX & 0xF0) | (unsigned char) mux; // select channel
+
+ //ADMUX |= (1<<REFS1) | (1<<REFS0); // interne Referenzspannung nutzen
+
+ /* nach Aktivieren des ADC wird ein "Dummy-Readout" empfohlen, man liest
+ also einen Wert und verwirft diesen, um den ADC "warmlaufen zu lassen" */
+
+ ADCSRA |= (1<<ADSC); // eine ADC-Wandlung
+ while ( ADCSRA & (1<<ADSC) ) {
+ ; // auf Abschluss der Konvertierung warten
+ }
+ result = ADCW; // ADCW muss einmal gelesen werden,
+ // sonst wird Ergebnis der nächsten Wandlung
+ // nicht übernommen.
+
+ /* Eigentliche Messung - Mittelwert aus 4 aufeinanderfolgenden Wandlungen */
+ result = 0;
+ for( i=0; i<4; i++ )
+ {
+ ADCSRA |= (1<<ADSC); // eine Wandlung "single conversion"
+ while ( ADCSRA & (1<<ADSC) ) {
+ ; // auf Abschluss der Konvertierung warten
+ }
+ result += ADCW; // Wandlungsergebnisse aufaddieren
+ }
+ ADCSRA &= ~(1<<ADEN); // ADC deaktivieren (2)
+
+ result /= 4; // Summe durch vier teilen = arithm. Mittelwert
+
+ return result;
+}