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#ifndef _ANALOG_H
#define _ANALOG_H
#include <inttypes.h>
#include "configuration.h"
/*
* How much low pass filtering to apply for gyro_PID.
* 0=illegal, 1=no filtering, 2=50% last value + 50% new value, 3=67% last value + 33 % new value etc...
* Temporarily replaced by userparam-configurable variable.
*/
// #define GYROS_PID_FILTER 1
/*
* How much low pass filtering to apply for gyro_ATT.
* 0=illegal, 1=no filtering, 2=50% last value + 50% new value, 3=67% last value + 33 % new value etc...
* Temporarily replaced by userparam-configurable variable.
*/
// #define GYROS_ATT_FILTER 1
// #define ACC_FILTER 4
/*
About setting constants for different gyros:
Main parameters are positive directions and voltage/angular speed gain.
The "Positive direction" is the rotation direction around an axis where
the corresponding gyro outputs a voltage > the no-rotation voltage.
A gyro is considered, in this code, to be "forward" if its positive
direction is:
- Nose down for pitch
- Left hand side down for roll
- Clockwise seen from above for yaw.
Setting gyro gain correctly: All sensor measurements in analog.c take
place in a cycle, each cycle comprising all sensors. Some sensors are
sampled more than ones, and the results added. The pitch and roll gyros
are sampled 4 times and the yaw gyro 2 times in the original H&I V0.74
code.
In the H&I code, the results for pitch and roll are multiplied by 2 (FC1.0)
or 4 (other versions), offset to zero, low pass filtered and then assigned
to the "HiResXXXX" and "AdWertXXXXFilter" variables, where XXXX is nick or
roll.
So:
gyro = V * (ADCValue1 + ADCValue2 + ADCValue3 + ADCValue4),
where V is 2 for FC1.0 and 4 for all others.
Assuming constant ADCValue, in the H&I code:
gyro = I * ADCValue.
where I is 8 for FC1.0 and 16 for all others.
The relation between rotation rate and ADCValue:
ADCValue [units] =
rotational speed [deg/s] *
gyro sensitivity [V / deg/s] *
amplifier gain [units] *
1024 [units] /
3V full range [V]
or: H is the number of steps the ADC value changes with,
for a 1 deg/s change in rotational velocity:
H = ADCValue [units] / rotation rate [deg/s] =
gyro sensitivity [V / deg/s] *
amplifier gain [units] *
1024 [units] /
3V full range [V]
Examples:
FC1.3 has 0.67 mV/deg/s gyros and amplifiers with a gain of 5.7:
H = 0.00067 V / deg / s * 5.7 * 1024 / 3V = 1.304 units/(deg/s).
FC2.0 has 6*(3/5) mV/deg/s gyros (they are ratiometric) and no amplifiers:
H = 0.006 V / deg / s * 1 * 1024 * 3V / (3V * 5V) = 1.2288 units/(deg/s).
My InvenSense copter has 2mV/deg/s gyros and no amplifiers:
H = 0.002 V / deg / s * 1 * 1024 / 3V = 0.6827 units/(deg/s)
(only about half as sensitive as V1.3. But it will take about twice the
rotation rate!)
All together: gyro = I * H * rotation rate [units / (deg/s)].
*/
/*
* A factor that the raw gyro values are multiplied by,
* before being filtered and passed to the attitude module.
* A value of 1 would cause a little bit of loss of precision in the
* filtering (on the other hand the values are so noisy in flight that
* it will not really matter - but when testing on the desk it might be
* noticeable). 4 is fine for the default filtering.
* Experiment: Set it to 1.
*/
#define GYRO_FACTOR_PITCHROLL 1
/*
* How many samples are summed in one ADC loop, for pitch&roll and yaw,
* respectively. This is = the number of occurences of each channel in the
* channelsForStates array in analog.c.
*/
#define GYRO_SUMMATION_FACTOR_PITCHROLL 4
#define GYRO_SUMMATION_FACTOR_YAW 2
#define ACC_SUMMATION_FACTOR_PITCHROLL 2
#define ACC_SUMMATION_FACTOR_Z 1
/*
Integration:
The HiResXXXX values are divided by 8 (in H&I firmware) before integration.
In the Killagreg rewrite of the H&I firmware, the factor 8 is called
HIRES_GYRO_AMPLIFY. In this code, it is called HIRES_GYRO_INTEGRATION_FACTOR,
and care has been taken that all other constants (gyro to degree factor, and
180 degree flip-over detection limits) are corrected to it. Because the
division by the constant takes place in the flight attitude code, the
constant is there.
The control loop executes every 2ms, and for each iteration
gyro_ATT[PITCH/ROLL] is added to gyroIntegral[PITCH/ROLL].
Assuming a constant rotation rate v and a zero initial gyroIntegral
(for this explanation), we get:
gyroIntegral =
N * gyro / HIRES_GYRO_INTEGRATION_FACTOR =
N * I * H * v / HIRES_GYRO_INTEGRATION_FACTOR
where N is the number of summations; N = t/2ms.
For one degree of rotation: t*v = 1:
gyroIntegralXXXX = t/2ms * I * H * 1/t = INTEGRATION_FREQUENCY * I * H / HIRES_GYRO_INTEGRATION_FACTOR.
This number (INTEGRATION_FREQUENCY * I * H) is the integral-to-degree factor.
Examples:
FC1.3: I=2, H=1.304, HIRES_GYRO_INTEGRATION_FACTOR=8 --> integralDegreeFactor = 1304
FC2.0: I=2, H=2.048, HIRES_GYRO_INTEGRATION_FACTOR=13 --> integralDegreeFactor = 1260
My InvenSense copter: HIRES_GYRO_INTEGRATION_FACTOR=4, H=0.6827 --> integralDegreeFactor = 1365
*/
/*
* The value of gyro[PITCH/ROLL] for one deg/s = The hardware factor H * the number of samples * multiplier factor.
* Will be about 10 or so for InvenSense, and about 33 for ADXRS610.
*/
#define GYRO_RATE_FACTOR_PITCHROLL (GYRO_HW_FACTOR * GYRO_SUMMATION_FACTOR_PITCHROLL * GYRO_FACTOR_PITCHROLL)
#define GYRO_RATE_FACTOR_YAW (GYRO_HW_FACTOR * GYRO_SUMMATION_FACTOR_YAW)
/*
* Gyro saturation prevention.
*/
// How far from the end of its range a gyro is considered near-saturated.
#define SENSOR_MIN_PITCHROLL 32
// Other end of the range (calculated)
#define SENSOR_MAX_PITCHROLL (GYRO_SUMMATION_FACTOR_PITCHROLL * 1023 - SENSOR_MIN_PITCHROLL)
// Max. boost to add "virtually" to gyro signal at total saturation.
#define EXTRAPOLATION_LIMIT 2500
// Slope of the boost (calculated)
#define EXTRAPOLATION_SLOPE (EXTRAPOLATION_LIMIT/SENSOR_MIN_PITCHROLL)
/*
* This value is subtracted from the gyro noise measurement in each iteration,
* making it return towards zero.
*/
#define GYRO_NOISE_MEASUREMENT_DAMPING 5
#define PITCH 0
#define ROLL 1
#define YAW 2
#define Z 2
/*
* The values that this module outputs
* These first 2 exported arrays are zero-offset. The "PID" ones are used
* in the attitude control as rotation rates. The "ATT" ones are for
* integration to angles. For the same axis, the PID and ATT variables
* generally have about the same values. There are just some differences
* in filtering, and when a gyro becomes near saturated.
* Maybe this distinction is not really necessary.
*/
extern int16_t gyro_PID[2];
extern int16_t gyro_ATT[2];
extern int16_t gyroD[2];
extern int16_t yawGyro;
extern volatile uint16_t ADCycleCount;
extern int16_t UBat;
// 1:11 voltage divider, 1024 counts per 3V, and result is divided by 3.
#define UBAT_AT_5V (int16_t)((5.0 * (1.0/11.0)) * 1024 / (3.0 * 3))
extern sensorOffset_t gyroOffset;
extern sensorOffset_t accOffset;
extern sensorOffset_t gyroAmplifierOffset;
/*
* This is not really for external use - but the ENC-03 gyro modules needs it.
*/
//extern volatile int16_t rawGyroSum[3];
/*
* The acceleration values that this module outputs. They are zero based.
*/
extern int16_t acc[3];
extern int16_t filteredAcc[3];
// extern volatile int32_t stronglyFilteredAcc[3];
/*
* Diagnostics: Gyro noise level because of motor vibrations. The variables
* only really reflect the noise level when the copter stands still but with
* its motors running.
*/
extern uint16_t gyroNoisePeak[3];
extern uint16_t accNoisePeak[3];
/*
* Air pressure.
* The sensor has a sensitivity of 45 mV/kPa.
* An approximate p(h) formula is = p(h[m])[kPa] = p_0 - 11.95 * 10^-3 * h
* p(h[m])[kPa] = 101.3 - 11.95 * 10^-3 * h
* 11.95 * 10^-3 * h = 101.3 - p[kPa]
* h = (101.3 - p[kPa])/0.01195
* That is: dV = -45 mV * 11.95 * 10^-3 dh = -0.53775 mV / m.
* That is, with 38.02 * 1.024 / 3 steps per mV: -7 steps / m
Display pressures
4165 mV-->1084.7
4090 mV-->1602.4 517.7
3877 mV-->3107.8 1503.4
4165 mV-->1419.1
3503 mV-->208.1
Diff.: 1211.0
Calculated Vout = 5V(.009P-0.095) --> 5V .009P = Vout + 5V 0.095 --> P = (Vout + 5V 0.095)/(5V 0.009)
4165 mV = 5V(0.009P-0.095) P = 103.11 kPa h = -151.4m
4090 mV = 5V(0.009P-0.095) P = 101.44 kPa h = -11.7m 139.7m
3877 mV = 5V(0.009P-0.095) P = 96.7 kPa h = 385m 396.7m
4165 mV = 5V(0.009P-0.095) P = 103.11 kPa h = -151.4m
3503 mV = 5V(0.009P-0.095) P = 88.4 kPa h = 384m Diff: 1079.5m
Pressure at sea level: 101.3 kPa. voltage: 5V * (0.009P-0.095) = 4.0835V
This is OCR2 = 143.15 at 1.5V in --> simple pressure =
*/
#define AIRPRESSURE_SUMMATION_FACTOR 14
#define AIRPRESSURE_FILTER 8
// Minimum A/D value before a range change is performed.
#define MIN_RAWPRESSURE (200 * 2)
// Maximum A/D value before a range change is performed.
#define MAX_RAWPRESSURE (1023 * 2 - MIN_RAWPRESSURE)
#define MIN_RANGES_EXTRAPOLATION 15
#define MAX_RANGES_EXTRAPOLATION 240
#define PRESSURE_EXTRAPOLATION_COEFF 25L
#define AUTORANGE_WAIT_FACTOR 1
#define ABS_ALTITUDE_OFFSET 108205
extern uint16_t simpleAirPressure;
/*
* At saturation, the filteredAirPressure may actually be (simulated) negative.
*/
extern int32_t filteredAirPressure;
/*
* Flag: Interrupt handler has done all A/D conversion and processing.
*/
extern volatile uint8_t analogDataReady;
void analog_init(void);
/*
* This is really only for use for the ENC-03 code module, which needs to get the raw value
* for its calibration. The raw value should not be used for anything else.
*/
uint16_t rawGyroValue(uint8_t axis);
/*
* Start the conversion cycle. It will stop automatically.
*/
void startAnalogConversionCycle(void);
/*
* Process the sensor data to update the exported variables. Must be called after each measurement cycle and before the data is used.
*/
void analog_update(void);
/*
* Read gyro and acc.meter calibration from EEPROM.
*/
void analog_setNeutral(void);
/*
* Zero-offset gyros and write the calibration data to EEPROM.
*/
void analog_calibrateGyros(void);
/*
* Zero-offset accelerometers and write the calibration data to EEPROM.
*/
void analog_calibrateAcc(void);
#endif //_ANALOG_H