aepko/Ardupilot2
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added generic ADC library.

Browse Source 
git-svn-id: https://arducopter.googlecode.com/svn/trunk@946 f9c3cf11-9bcb-44bc-f272-b75c42450872
This commit is contained in:
james.goppert 2010-11-27 04:41:25 +00:00
parent 607b86c9a2
commit e865622f66
6 changed files with 298 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
libraries/APM_ADC/AP_ADC.cpp Normal file
View File

@ -0,0 +1,23 @@
/*
ADC.cpp - Analog Digital Converter Base Class for Ardupilot Mega
Code by James Goppert. DIYDrones.com
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
*/
#include "AP_ADC.h"
AP_ADC::AP_ADC()
{
}
void AP_ADC::Init()
{
}
int AP_ADC::Ch(unsigned char ch_num)
{
}

31
libraries/APM_ADC/AP_ADC.h Normal file
View File

@ -0,0 +1,31 @@
#ifndef AP_ADC_H
#define AP_ADC_H
/*
AP_ADC.cpp - Analog Digital Converter Base Class for Ardupilot Mega
Code by James Goppert. DIYDrones.com
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
Methods:
Init() : Initialization of ADC. (interrupts etc)
Ch(ch_num) : Return the ADC channel value
*/
class AP_ADC
{
public:
AP_ADC(); // Constructor
virtual void Init();
virtual int Ch(unsigned char ch_num);
private:
};
#include "AP_ADC_ADS7844.h"
#include "AP_ADC_HIL.h"
#endif

146
libraries/APM_ADC/AP_ADC_ADS7844.cpp Normal file
View File

@ -0,0 +1,146 @@
/*
AP_ADC_ADS7844.cpp - ADC ADS7844 Library for Ardupilot Mega
Code by Jordi Muñoz and Jose Julio. DIYDrones.com
Modified by John Ihlein 6/19/2010 to:
1)Prevent overflow of adc_counter when more than 8 samples collected between reads. Probably
only an issue on initial read of ADC at program start.
2)Reorder analog read order as follows:
p, q, r, ax, ay, az
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
External ADC ADS7844 is connected via Serial port 2 (in SPI mode)
TXD2 = MOSI = pin PH1
RXD2 = MISO = pin PH0
XCK2 = SCK = pin PH2
Chip Select pin is PC4 (33) [PH6 (9)]
We are using the 16 clocks per conversion timming to increase efficiency (fast)
The sampling frequency is 400Hz (Timer2 overflow interrupt)
So if our loop is at 50Hz, our needed sampling freq should be 100Hz, so
we have an 4x oversampling and averaging.
Methods:
Init() : Initialization of interrupts an Timers (Timer2 overflow interrupt)
Ch(ch_num) : Return the ADC channel value
// HJI - Input definitions. USB connector assumed to be on the left, Rx and servo
// connector pins to the rear. IMU shield components facing up. These are board
// referenced sensor inputs, not device referenced.
On Ardupilot Mega Hardware, oriented as described above:
Chennel 0 : yaw rate, r
Channel 1 : roll rate, p
Channel 2 : pitch rate, q
Channel 3 : x/y gyro temperature
Channel 4 : x acceleration, aX
Channel 5 : y acceleration, aY
Channel 6 : z acceleration, aZ
Channel 7 : Differential pressure sensor port
*/
extern "C" {
// AVR LibC Includes
#include <inttypes.h>
#include <avr/interrupt.h>
#include "WConstants.h"
}
#include "AP_ADC_ADS7844.h"
// Commands for reading ADC channels on ADS7844
static const unsigned char adc_cmd[9]= { 0x87, 0xC7, 0x97, 0xD7, 0xA7, 0xE7, 0xB7, 0xF7, 0x00 };
static volatile long adc_value[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
static volatile unsigned char adc_counter[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
static unsigned char ADC_SPI_transfer(unsigned char data)
{
/* Wait for empty transmit buffer */
while ( !( UCSR2A & (1<<UDRE2)) );
/* Put data into buffer, sends the data */
UDR2 = data;
/* Wait for data to be received */
while ( !(UCSR2A & (1<<RXC2)) );
/* Get and return received data from buffer */
return UDR2;
}
ISR (TIMER2_OVF_vect)
{
uint8_t ch;
unsigned int adc_tmp;
//bit_set(PORTL,6); // To test performance
bit_clear(PORTC,4); // Enable Chip Select (PIN PC4)
ADC_SPI_transfer(adc_cmd[0]); // Command to read the first channel
for (ch=0;ch<8;ch++)
{
if (adc_counter[ch] >= 17) // HJI - Added this to prevent
{ // overflow of adc_value
adc_value[ch] = 0;
adc_counter[ch] = 0;
}
adc_tmp = ADC_SPI_transfer(0)<<8; // Read first byte
adc_tmp |= ADC_SPI_transfer(adc_cmd[ch+1]); // Read second byte and send next command
adc_value[ch] += adc_tmp>>3; // Shift to 12 bits
adc_counter[ch]++; // Number of samples
}
bit_set(PORTC,4); // Disable Chip Select (PIN PC4)
//bit_clear(PORTL,6); // To test performance
TCNT2 = 104; // 400 Hz
}
// Constructors ////////////////////////////////////////////////////////////////
AP_ADC_ADS7844::AP_ADC_ADS7844()
{
}
// Public Methods //////////////////////////////////////////////////////////////
void AP_ADC_ADS7844::Init(void)
{
unsigned char tmp;
pinMode(ADC_CHIP_SELECT,OUTPUT);
digitalWrite(ADC_CHIP_SELECT,HIGH); // Disable device (Chip select is active low)
// Setup Serial Port2 in SPI mode
UBRR2 = 0;
DDRH |= (1<<PH2); // SPI clock XCK2 (PH2) as output. This enable SPI Master mode
// Set MSPI mode of operation and SPI data mode 0.
UCSR2C = (1<<UMSEL21)|(1<<UMSEL20); //|(0<<UCPHA2)|(0<<UCPOL2);
// Enable receiver and transmitter.
UCSR2B = (1<<RXEN2)|(1<<TXEN2);
// Set Baud rate
UBRR2 = 2; // SPI clock running at 2.6MHz
// Enable Timer2 Overflow interrupt to capture ADC data
TIMSK2 = 0; // Disable interrupts
TCCR2A = 0; // normal counting mode
TCCR2B = _BV(CS21)|_BV(CS22); // Set prescaler of 256
TCNT2 = 0;
TIFR2 = _BV(TOV2); // clear pending interrupts;
TIMSK2 = _BV(TOIE2) ; // enable the overflow interrupt
}
// Read one channel value
int AP_ADC_ADS7844::Ch(unsigned char ch_num)
{
int result;
cli(); // We stop interrupts to read the variables
if (adc_counter[ch_num]>0)
result = adc_value[ch_num]/adc_counter[ch_num];
else
result = 0;
adc_value[ch_num] = 0; // Initialize for next reading
adc_counter[ch_num] = 0;
sei();
return(result);
}

24
libraries/APM_ADC/AP_ADC_ADS7844.h Normal file
View File

@ -0,0 +1,24 @@
#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
#include "AP_ADC.h"
class AP_ADC_ADS7844 : public AP_ADC
{
public:
AP_ADC_ADS7844(); // Constructor
void Init();
int Ch(unsigned char ch_num);
private:
};
#endif

42
libraries/APM_ADC/AP_ADC_HIL.cpp Normal file
View File

@ -0,0 +1,42 @@
#include "AP_ADC_HIL.h"
const uint8_t AP_ADC_HIL::sensors[6] = {1,2,0,4,5,6};
const int AP_ADC_HIL::sensorSign[9] = { 1, -1, -1,
-1, 1, 1,
-1, -1, -1};
AP_ADC_HIL::AP_ADC_HIL() : adc_value()
{
}
void AP_ADC_HIL::Init(void)
{
}
// Read one channel value
int AP_ADC_HIL::Ch(unsigned char ch_num)
{
return adc_value[ch_num];
}
// Set one channel value
int AP_ADC_HIL::setHIL(int16_t p, int16_t q, int16_t r, int16_t gyroTemp,
int16_t aX, int16_t aY, int16_t aZ, int16_t diffPress)
{
// TODO: map temp and press to raw
// gyros
/* 0 */ adc_value[sensors[0]] = sensorSign[0]* p/(gyroGainX*deg2rad*1000) + 1665; // note apm says 1,2,0 gyro order, but
/* 1 */ adc_value[sensors[1]] = sensorSign[1]* q/(gyroGainY*deg2rad*1000) + 1665; // this says 0,1,2
/* 2 */ adc_value[sensors[2]] = sensorSign[2]* r/(gyroGainZ*deg2rad*1000) + 1665;
// gyro temp
/* 3 */ adc_value[3] = sensorSign[3]* gyroTemp; //gyroTemp XXX: fix scaling;
// accelerometers
/* 4 */ adc_value[sensors[3]] = sensorSign[4]* (aX*adcPerG)/1.0e3 + 2025;
/* 5 */ adc_value[sensors[4]] = sensorSign[5]* (aY*adcPerG)/1.0e3 + 2025;
/* 6 */ adc_value[sensors[5]] = sensorSign[6]* (aZ*adcPerG)/1.0e3 + 2025;
// differential pressure
/* 7 */ adc_value[7] = sensorSign[7]* diffPress; //diffPress XXX: fix scaling;
}

32
libraries/APM_ADC/AP_ADC_HIL.h Normal file
View File

@ -0,0 +1,32 @@
#ifndef AP_ADC_HIL_H
#define AP_ADC_HIL_H
/*
AP_ADC_HIL.cpp - HIL model of ADC ADS7844 for Ardupilot Mega
Code by James Goppert. DIYDrones.com
*/
#include <inttypes.h>
#include "AP_ADC.h"
class AP_ADC_HIL : public AP_ADC
{
public:
AP_ADC_HIL(); // Constructor
void Init();
int Ch(unsigned char ch_num);
int setHIL(int16_t p, int16_t q, int16_t r, int16_t gyroTemp,
int16_t aX, int16_t aY, int16_t aZ, int16_t diffPress);
private:
static const uint16_t adcPerG = 418;
static const float gyroGainX = 0.4;
static const float gyroGainY = 0.41;
static const float gyroGainZ = 0.41;
static const float deg2rad = 3.14159/180.0;
static const uint8_t sensors[6];
static const int sensorSign[9];
long adc_value[8];
};
#endif