X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=altoslib%2Fsrc%2Forg%2Faltusmetrum%2FAltosLib%2FAltosConvert.java;fp=altoslib%2Fsrc%2Forg%2Faltusmetrum%2FAltosLib%2FAltosConvert.java;h=0000000000000000000000000000000000000000;hb=69e6df07976a56b49e07c242cd6e5b2cbd2a578d;hp=3527b575178a2291ceb62b5729c3987af756f618;hpb=9b659904109f992b8a3e61efb94e81cdb19af1c9;p=fw%2Faltos diff --git a/altoslib/src/org/altusmetrum/AltosLib/AltosConvert.java b/altoslib/src/org/altusmetrum/AltosLib/AltosConvert.java deleted file mode 100644 index 3527b575..00000000 --- a/altoslib/src/org/altusmetrum/AltosLib/AltosConvert.java +++ /dev/null @@ -1,259 +0,0 @@ -/* - * Copyright © 2010 Keith Packard - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; version 2 of the License. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. - */ - -/* - * Sensor data conversion functions - */ -package org.altusmetrum.AltosLib; - -public class AltosConvert { - /* - * Pressure Sensor Model, version 1.1 - * - * written by Holly Grimes - * - * Uses the International Standard Atmosphere as described in - * "A Quick Derivation relating altitude to air pressure" (version 1.03) - * from the Portland State Aerospace Society, except that the atmosphere - * is divided into layers with each layer having a different lapse rate. - * - * Lapse rate data for each layer was obtained from Wikipedia on Sept. 1, 2007 - * at site MAXIMUM_ALTITUDE) /* FIX ME: use sensor data to improve model */ - return 0; - - /* calculate the base temperature and pressure for the atmospheric layer - associated with the inputted altitude */ - for(layer_number = 0; layer_number < NUMBER_OF_LAYERS - 1 && altitude > base_altitude[layer_number + 1]; layer_number++) { - delta_z = base_altitude[layer_number + 1] - base_altitude[layer_number]; - if (lapse_rate[layer_number] == 0.0) { - exponent = GRAVITATIONAL_ACCELERATION * delta_z - / AIR_GAS_CONSTANT / base_temperature; - base_pressure *= Math.exp(exponent); - } - else { - base = (lapse_rate[layer_number] * delta_z / base_temperature) + 1.0; - exponent = GRAVITATIONAL_ACCELERATION / - (AIR_GAS_CONSTANT * lapse_rate[layer_number]); - base_pressure *= Math.pow(base, exponent); - } - base_temperature += delta_z * lapse_rate[layer_number]; - } - - /* calculate the pressure at the inputted altitude */ - delta_z = altitude - base_altitude[layer_number]; - if (lapse_rate[layer_number] == 0.0) { - exponent = GRAVITATIONAL_ACCELERATION * delta_z - / AIR_GAS_CONSTANT / base_temperature; - pressure = base_pressure * Math.exp(exponent); - } - else { - base = (lapse_rate[layer_number] * delta_z / base_temperature) + 1.0; - exponent = GRAVITATIONAL_ACCELERATION / - (AIR_GAS_CONSTANT * lapse_rate[layer_number]); - pressure = base_pressure * Math.pow(base, exponent); - } - - return pressure; - } - - -/* outputs the altitude associated with the given pressure. the altitude - returned is measured with respect to the mean sea level */ - public static double - pressure_to_altitude(double pressure) - { - - double next_base_temperature = LAYER0_BASE_TEMPERATURE; - double next_base_pressure = LAYER0_BASE_PRESSURE; - - double altitude; - double base_pressure; - double base_temperature; - double base; /* base for function to determine base pressure of next layer */ - double exponent; /* exponent for function to determine base pressure - of next layer */ - double coefficient; - int layer_number; /* identifies layer in the atmosphere */ - int delta_z; /* difference between two altitudes */ - - if (pressure < 0) /* illegal pressure */ - return -1; - if (pressure < MINIMUM_PRESSURE) /* FIX ME: use sensor data to improve model */ - return MAXIMUM_ALTITUDE; - - /* calculate the base temperature and pressure for the atmospheric layer - associated with the inputted pressure. */ - layer_number = -1; - do { - layer_number++; - base_pressure = next_base_pressure; - base_temperature = next_base_temperature; - delta_z = base_altitude[layer_number + 1] - base_altitude[layer_number]; - if (lapse_rate[layer_number] == 0.0) { - exponent = GRAVITATIONAL_ACCELERATION * delta_z - / AIR_GAS_CONSTANT / base_temperature; - next_base_pressure *= Math.exp(exponent); - } - else { - base = (lapse_rate[layer_number] * delta_z / base_temperature) + 1.0; - exponent = GRAVITATIONAL_ACCELERATION / - (AIR_GAS_CONSTANT * lapse_rate[layer_number]); - next_base_pressure *= Math.pow(base, exponent); - } - next_base_temperature += delta_z * lapse_rate[layer_number]; - } - while(layer_number < NUMBER_OF_LAYERS - 1 && pressure < next_base_pressure); - - /* calculate the altitude associated with the inputted pressure */ - if (lapse_rate[layer_number] == 0.0) { - coefficient = (AIR_GAS_CONSTANT / GRAVITATIONAL_ACCELERATION) - * base_temperature; - altitude = base_altitude[layer_number] - + coefficient * Math.log(pressure / base_pressure); - } - else { - base = pressure / base_pressure; - exponent = AIR_GAS_CONSTANT * lapse_rate[layer_number] - / GRAVITATIONAL_ACCELERATION; - coefficient = base_temperature / lapse_rate[layer_number]; - altitude = base_altitude[layer_number] - + coefficient * (Math.pow(base, exponent) - 1); - } - - return altitude; - } - - public static double - cc_battery_to_voltage(double battery) - { - return battery / 32767.0 * 5.0; - } - - public static double - cc_ignitor_to_voltage(double ignite) - { - return ignite / 32767 * 15.0; - } - - public static double radio_to_frequency(int freq, int setting, int cal, int channel) { - double f; - - if (freq > 0) - f = freq / 1000.0; - else { - if (setting <= 0) - setting = cal; - f = 434.550 * setting / cal; - /* Round to nearest 50KHz */ - f = Math.floor (20.0 * f + 0.5) / 20.0; - } - return f + channel * 0.100; - } - - public static int radio_frequency_to_setting(double frequency, int cal) { - double set = frequency / 434.550 * cal; - - return (int) Math.floor (set + 0.5); - } - - public static int radio_frequency_to_channel(double frequency) { - int channel = (int) Math.floor ((frequency - 434.550) / 0.100 + 0.5); - - if (channel < 0) - channel = 0; - if (channel > 9) - channel = 9; - return channel; - } - - public static double radio_channel_to_frequency(int channel) { - return 434.550 + channel * 0.100; - } - - public static int[] ParseHex(String line) { - String[] tokens = line.split("\\s+"); - int[] array = new int[tokens.length]; - - for (int i = 0; i < tokens.length; i++) - try { - array[i] = Integer.parseInt(tokens[i], 16); - } catch (NumberFormatException ne) { - return null; - } - return array; - } - - public static double meters_to_feet(double meters) { - return meters * (100 / (2.54 * 12)); - } - - public static double meters_to_mach(double meters) { - return meters / 343; /* something close to mach at usual rocket sites */ - } - - public static double meters_to_g(double meters) { - return meters / 9.80665; - } - - public static int checksum(int[] data, int start, int length) { - int csum = 0x5a; - for (int i = 0; i < length; i++) - csum += data[i + start]; - return csum & 0xff; - } -}