mirror of https://github.com/ArduPilot/ardupilot
fixed formatting of ADC driver
it was a nasty mix of DOS and UNIX
This commit is contained in:
Andrew Tridgell
parent
b484411c41
commit
f125f6619a
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@ -1,133 +1,134 @@
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/*
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AP_ADC_ADS7844.cpp - ADC ADS7844 Library for Ardupilot Mega
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Code by Jordi Mu<EFBFBD>oz and Jose Julio. DIYDrones.com
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Modified by John Ihlein 6 / 19 / 2010 to:
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1)Prevent overflow of adc_counter when more than 8 samples collected between reads. Probably
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only an issue on initial read of ADC at program start.
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2)Reorder analog read order as follows:
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p, q, r, ax, ay, az
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This library is free software; you can redistribute it and / or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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External ADC ADS7844 is connected via Serial port 2 (in SPI mode)
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TXD2 = MOSI = pin PH1
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RXD2 = MISO = pin PH0
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XCK2 = SCK = pin PH2
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Chip Select pin is PC4 (33) [PH6 (9)]
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We are using the 16 clocks per conversion timming to increase efficiency (fast)
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The sampling frequency is 1kHz (Timer2 overflow interrupt)
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So if our loop is at 50Hz, our needed sampling freq should be 100Hz, so
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we have an 10x oversampling and averaging.
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Methods:
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Init() : Initialization of interrupts an Timers (Timer2 overflow interrupt)
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Ch(ch_num) : Return the ADC channel value
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// HJI - Input definitions. USB connector assumed to be on the left, Rx and servo
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// connector pins to the rear. IMU shield components facing up. These are board
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// referenced sensor inputs, not device referenced.
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On Ardupilot Mega Hardware, oriented as described above:
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Chennel 0 : yaw rate, r
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Channel 1 : roll rate, p
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Channel 2 : pitch rate, q
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Channel 3 : x / y gyro temperature
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Channel 4 : x acceleration, aX
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Channel 5 : y acceleration, aY
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Channel 6 : z acceleration, aZ
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Channel 7 : Differential pressure sensor port
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*/
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extern "C" {
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// AVR LibC Includes
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#include <inttypes.h>
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#include <stdint.h>
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#include <avr/interrupt.h>
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#include "WConstants.h"
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}
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#include "AP_ADC_ADS7844.h"
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// Commands for reading ADC channels on ADS7844
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static const unsigned char adc_cmd[9] = { 0x87, 0xC7, 0x97, 0xD7, 0xA7, 0xE7, 0xB7, 0xF7, 0x00 };
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// the sum of the values since last read
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static volatile uint32_t _sum[8];
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// how many values we've accumulated since last read
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static volatile uint16_t _count[8];
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static uint32_t last_ch6_micros;
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// TCNT2 values for various interrupt rates,
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// assuming 256 prescaler. Note that these values
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// assume a zero-time ISR. The actual rate will be a
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// bit lower than this
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#define TCNT2_781_HZ (256-80)
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#define TCNT2_1008_HZ (256-62)
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#define TCNT2_1302_HZ (256-48)
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static inline unsigned char ADC_SPI_transfer(unsigned char data)
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{
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/* Put data into buffer, sends the data */
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UDR2 = data;
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/* Wait for data to be received */
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while ( !(UCSR2A & (1 << RXC2)) );
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/* Get and return received data from buffer */
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return UDR2;
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}
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/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
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/*
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AP_ADC_ADS7844.cpp - ADC ADS7844 Library for Ardupilot Mega
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Code by Jordi Mu<EFBFBD>oz and Jose Julio. DIYDrones.com
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Modified by John Ihlein 6 / 19 / 2010 to:
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1)Prevent overflow of adc_counter when more than 8 samples collected between reads. Probably
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only an issue on initial read of ADC at program start.
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2)Reorder analog read order as follows:
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p, q, r, ax, ay, az
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This library is free software; you can redistribute it and / or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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External ADC ADS7844 is connected via Serial port 2 (in SPI mode)
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TXD2 = MOSI = pin PH1
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RXD2 = MISO = pin PH0
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XCK2 = SCK = pin PH2
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Chip Select pin is PC4 (33) [PH6 (9)]
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We are using the 16 clocks per conversion timming to increase efficiency (fast)
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The sampling frequency is 1kHz (Timer2 overflow interrupt)
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So if our loop is at 50Hz, our needed sampling freq should be 100Hz, so
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we have an 10x oversampling and averaging.
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Methods:
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Init() : Initialization of interrupts an Timers (Timer2 overflow interrupt)
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Ch(ch_num) : Return the ADC channel value
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// HJI - Input definitions. USB connector assumed to be on the left, Rx and servo
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// connector pins to the rear. IMU shield components facing up. These are board
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// referenced sensor inputs, not device referenced.
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On Ardupilot Mega Hardware, oriented as described above:
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Chennel 0 : yaw rate, r
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Channel 1 : roll rate, p
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Channel 2 : pitch rate, q
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Channel 3 : x / y gyro temperature
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Channel 4 : x acceleration, aX
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Channel 5 : y acceleration, aY
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Channel 6 : z acceleration, aZ
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Channel 7 : Differential pressure sensor port
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*/
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extern "C" {
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// AVR LibC Includes
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#include <inttypes.h>
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#include <stdint.h>
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#include <avr/interrupt.h>
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#include "WConstants.h"
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}
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#include "AP_ADC_ADS7844.h"
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// Commands for reading ADC channels on ADS7844
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static const unsigned char adc_cmd[9] = { 0x87, 0xC7, 0x97, 0xD7, 0xA7, 0xE7, 0xB7, 0xF7, 0x00 };
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// the sum of the values since last read
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static volatile uint32_t _sum[8];
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// how many values we've accumulated since last read
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static volatile uint16_t _count[8];
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static uint32_t last_ch6_micros;
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// TCNT2 values for various interrupt rates,
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// assuming 256 prescaler. Note that these values
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// assume a zero-time ISR. The actual rate will be a
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// bit lower than this
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#define TCNT2_781_HZ (256-80)
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#define TCNT2_1008_HZ (256-62)
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#define TCNT2_1302_HZ (256-48)
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static inline unsigned char ADC_SPI_transfer(unsigned char data)
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{
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/* Put data into buffer, sends the data */
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UDR2 = data;
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/* Wait for data to be received */
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while ( !(UCSR2A & (1 << RXC2)) );
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/* Get and return received data from buffer */
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return UDR2;
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}
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void AP_ADC_ADS7844::read(void)
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{
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uint8_t ch;
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bit_clear(PORTC, 4); // Enable Chip Select (PIN PC4)
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ADC_SPI_transfer(adc_cmd[0]); // Command to read the first channel
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for (ch = 0; ch < 8; ch++) {
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uint16_t v;
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v = ADC_SPI_transfer(0) << 8; // Read first byte
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v |= ADC_SPI_transfer(adc_cmd[ch + 1]); // Read second byte and send next command
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if (v & 0x8007) {
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// this is a 12-bit ADC, shifted by 3 bits.
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// if we get other bits set then the value is
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// bogus and should be ignored
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continue;
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}
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if (++_count[ch] == 0) {
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// overflow ... shouldn't happen too often
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// unless we're just not using the
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// channel. Notice that we overflow the count
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// to 1 here, not zero, as otherwise the
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// reader below could get a division by zero
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_sum[ch] = 0;
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_count[ch] = 1;
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last_ch6_micros = micros();
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}
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_sum[ch] += (v >> 3);
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}
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bit_set(PORTC, 4); // Disable Chip Select (PIN PC4)
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}
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// Constructors ////////////////////////////////////////////////////////////////
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AP_ADC_ADS7844::AP_ADC_ADS7844() :
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_filter_index_accel(0),
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filter_result(false)
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{
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}
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{
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uint8_t ch;
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bit_clear(PORTC, 4); // Enable Chip Select (PIN PC4)
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ADC_SPI_transfer(adc_cmd[0]); // Command to read the first channel
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for (ch = 0; ch < 8; ch++) {
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uint16_t v;
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v = ADC_SPI_transfer(0) << 8; // Read first byte
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v |= ADC_SPI_transfer(adc_cmd[ch + 1]); // Read second byte and send next command
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if (v & 0x8007) {
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// this is a 12-bit ADC, shifted by 3 bits.
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// if we get other bits set then the value is
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// bogus and should be ignored
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continue;
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}
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if (++_count[ch] == 0) {
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// overflow ... shouldn't happen too often
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// unless we're just not using the
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// channel. Notice that we overflow the count
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// to 1 here, not zero, as otherwise the
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// reader below could get a division by zero
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_sum[ch] = 0;
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_count[ch] = 1;
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last_ch6_micros = micros();
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}
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_sum[ch] += (v >> 3);
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}
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bit_set(PORTC, 4); // Disable Chip Select (PIN PC4)
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}
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// Constructors ////////////////////////////////////////////////////////////////
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AP_ADC_ADS7844::AP_ADC_ADS7844() :
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_filter_index_accel(0),
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filter_result(false)
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{
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}
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// Public Methods //////////////////////////////////////////////////////////////
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void AP_ADC_ADS7844::Init( AP_PeriodicProcess * scheduler )
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{
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@ -160,105 +161,105 @@ void AP_ADC_ADS7844::Init( AP_PeriodicProcess * scheduler )
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scheduler->register_process( AP_ADC_ADS7844::read );
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}
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// Read one channel value
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float AP_ADC_ADS7844::Ch(uint8_t ch_num)
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{
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uint16_t count;
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uint32_t sum;
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// ensure we have at least one value
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while (_count[ch_num] == 0) /* noop */ ;
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// grab the value with interrupts disabled, and clear the count
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cli();
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count = _count[ch_num];
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sum = _sum[ch_num];
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_count[ch_num] = 0;
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_sum[ch_num] = 0;
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sei();
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return ((float)sum)/count;
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}
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// Read 6 channel values
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// this assumes that the counts for all of the 6 channels are
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// equal. This will only be true if we always consistently access a
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// sensor by either Ch6() or Ch() and never mix them. If you mix them
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// then you will get very strange results
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uint32_t AP_ADC_ADS7844::Ch6(const uint8_t *channel_numbers, uint16_t *result)
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{
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uint16_t count[6];
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uint32_t sum[6];
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uint8_t i;
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// ensure we have at least one value
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for (i=0; i<6; i++) {
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while (_count[channel_numbers[i]] == 0) /* noop */;
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}
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// grab the values with interrupts disabled, and clear the counts
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cli();
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for (i=0; i<6; i++) {
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count[i] = _count[channel_numbers[i]];
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sum[i] = _sum[channel_numbers[i]];
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_count[channel_numbers[i]] = 0;
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_sum[channel_numbers[i]] = 0;
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}
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sei();
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// calculate averages. We keep this out of the cli region
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// to prevent us stalling the ISR while doing the
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// division. That costs us 36 bytes of stack, but I think its
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// worth it.
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for (i = 0; i < 6; i++) {
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// Read one channel value
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float AP_ADC_ADS7844::Ch(uint8_t ch_num)
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{
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uint16_t count;
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uint32_t sum;
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// ensure we have at least one value
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while (_count[ch_num] == 0) /* noop */ ;
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// grab the value with interrupts disabled, and clear the count
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cli();
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count = _count[ch_num];
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sum = _sum[ch_num];
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_count[ch_num] = 0;
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_sum[ch_num] = 0;
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sei();
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return ((float)sum)/count;
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}
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// Read 6 channel values
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// this assumes that the counts for all of the 6 channels are
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// equal. This will only be true if we always consistently access a
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// sensor by either Ch6() or Ch() and never mix them. If you mix them
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// then you will get very strange results
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uint32_t AP_ADC_ADS7844::Ch6(const uint8_t *channel_numbers, uint16_t *result)
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{
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uint16_t count[6];
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uint32_t sum[6];
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uint8_t i;
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// ensure we have at least one value
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for (i=0; i<6; i++) {
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while (_count[channel_numbers[i]] == 0) /* noop */;
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}
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// grab the values with interrupts disabled, and clear the counts
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cli();
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for (i=0; i<6; i++) {
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count[i] = _count[channel_numbers[i]];
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sum[i] = _sum[channel_numbers[i]];
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_count[channel_numbers[i]] = 0;
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_sum[channel_numbers[i]] = 0;
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}
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sei();
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// calculate averages. We keep this out of the cli region
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// to prevent us stalling the ISR while doing the
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// division. That costs us 36 bytes of stack, but I think its
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// worth it.
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for (i = 0; i < 6; i++) {
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result[i] = (sum[i] + (count[i]/2)) / count[i];
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}
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if(filter_result){
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uint32_t _sum_accel;
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// simple Gyro Filter
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for (i = 0; i < 3; i++) {
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// add prev filtered value to new raw value, divide by 2
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result[i] = (_prev_gyro[i] + result[i]) >> 1;
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// remember the filtered value
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_prev_gyro[i] = result[i];
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}
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// Accel filter
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for (i = 0; i < 3; i++) {
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// move most recent result into filter
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_filter_accel[i][_filter_index_accel] = result[i+3];
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// clear the sum
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_sum_accel = 0;
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// sum the filter
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for (uint8_t n = 0; n < ADC_ACCEL_FILTER_SIZE; n++) {
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_sum_accel += _filter_accel[i][n];
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}
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// filter does a moving average on last 8 reads, sums half with half of last filtered value
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// save old result
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_prev_accel[i] = result[i+3] = (_sum_accel >> 4) + (_prev_accel[i] >> 1); // divide by 16, divide by 2
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}
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// increment filter index
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_filter_index_accel++;
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// loop our filter
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if(_filter_index_accel == ADC_ACCEL_FILTER_SIZE)
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_filter_index_accel = 0;
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}
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// return number of microseconds since last call
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uint32_t us = micros();
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uint32_t ret = us - last_ch6_micros;
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last_ch6_micros = us;
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return ret;
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}
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}
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if(filter_result){
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uint32_t _sum_accel;
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// simple Gyro Filter
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for (i = 0; i < 3; i++) {
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// add prev filtered value to new raw value, divide by 2
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result[i] = (_prev_gyro[i] + result[i]) >> 1;
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// remember the filtered value
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_prev_gyro[i] = result[i];
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}
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// Accel filter
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for (i = 0; i < 3; i++) {
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// move most recent result into filter
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_filter_accel[i][_filter_index_accel] = result[i+3];
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// clear the sum
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_sum_accel = 0;
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// sum the filter
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for (uint8_t n = 0; n < ADC_ACCEL_FILTER_SIZE; n++) {
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_sum_accel += _filter_accel[i][n];
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}
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// filter does a moving average on last 8 reads, sums half with half of last filtered value
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// save old result
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_prev_accel[i] = result[i+3] = (_sum_accel >> 4) + (_prev_accel[i] >> 1); // divide by 16, divide by 2
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}
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// increment filter index
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_filter_index_accel++;
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// loop our filter
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if(_filter_index_accel == ADC_ACCEL_FILTER_SIZE)
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_filter_index_accel = 0;
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}
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// return number of microseconds since last call
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uint32_t us = micros();
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uint32_t ret = us - last_ch6_micros;
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last_ch6_micros = us;
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return ret;
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}
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@ -1,42 +1,43 @@
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#ifndef AP_ADC_ADS7844_H
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#define AP_ADC_ADS7844_H
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#define bit_set(p,m) ((p) |= ( 1<<m))
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#define bit_clear(p,m) ((p) &= ~(1<<m))
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// We use Serial Port 2 in SPI Mode
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#define ADC_DATAOUT 51 // MOSI
|
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#define ADC_DATAIN 50 // MISO
|
||||
#define ADC_SPICLOCK 52 // SCK
|
||||
#define ADC_CHIP_SELECT 33 // PC4 9 // PH6 Puerto:0x08 Bit mask : 0x40
|
||||
|
||||
// DO NOT CHANGE FROM 8!!
|
||||
#define ADC_ACCEL_FILTER_SIZE 8
|
||||
|
||||
#include "AP_ADC.h"
|
||||
/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
|
||||
#ifndef AP_ADC_ADS7844_H
|
||||
#define AP_ADC_ADS7844_H
|
||||
|
||||
#define bit_set(p,m) ((p) |= ( 1<<m))
|
||||
#define bit_clear(p,m) ((p) &= ~(1<<m))
|
||||
|
||||
// We use Serial Port 2 in SPI Mode
|
||||
#define ADC_DATAOUT 51 // MOSI
|
||||
#define ADC_DATAIN 50 // MISO
|
||||
#define ADC_SPICLOCK 52 // SCK
|
||||
#define ADC_CHIP_SELECT 33 // PC4 9 // PH6 Puerto:0x08 Bit mask : 0x40
|
||||
|
||||
// DO NOT CHANGE FROM 8!!
|
||||
#define ADC_ACCEL_FILTER_SIZE 8
|
||||
|
||||
#include "AP_ADC.h"
|
||||
#include "../AP_PeriodicProcess/AP_PeriodicProcess.h"
|
||||
#include <inttypes.h>
|
||||
|
||||
class AP_ADC_ADS7844 : public AP_ADC
|
||||
{
|
||||
public:
|
||||
AP_ADC_ADS7844(); // Constructor
|
||||
#include <inttypes.h>
|
||||
|
||||
class AP_ADC_ADS7844 : public AP_ADC
|
||||
{
|
||||
public:
|
||||
AP_ADC_ADS7844(); // Constructor
|
||||
void Init( AP_PeriodicProcess * scheduler );
|
||||
|
||||
// Read 1 sensor value
|
||||
float Ch(unsigned char ch_num);
|
||||
|
||||
// Read 6 sensors at once
|
||||
uint32_t Ch6(const uint8_t *channel_numbers, uint16_t *result);
|
||||
bool filter_result;
|
||||
|
||||
private:
|
||||
uint16_t _filter_accel[3][ADC_ACCEL_FILTER_SIZE];
|
||||
uint16_t _prev_gyro[3];
|
||||
uint16_t _prev_accel[3];
|
||||
uint8_t _filter_index_accel;
|
||||
|
||||
// Read 1 sensor value
|
||||
float Ch(unsigned char ch_num);
|
||||
|
||||
// Read 6 sensors at once
|
||||
uint32_t Ch6(const uint8_t *channel_numbers, uint16_t *result);
|
||||
bool filter_result;
|
||||
|
||||
private:
|
||||
uint16_t _filter_accel[3][ADC_ACCEL_FILTER_SIZE];
|
||||
uint16_t _prev_gyro[3];
|
||||
uint16_t _prev_accel[3];
|
||||
uint8_t _filter_index_accel;
|
||||
static void read( void );
|
||||
|
||||
};
|
||||
|
||||
#endif
|
||||
|
||||
};
|
||||
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in New Issue