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weatherbox:data_specification [2016/03/27 22:53] kluong [Converting from volts to w_m2] |
weatherbox:data_specification [2021/09/19 21:59] |
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| - | ====== Weatherbox Data Specification ====== | ||
| - | This page contains the data specification versions for the weatherbox. | ||
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| - | ====== 296 Basic Schema ====== | ||
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| - | This is a simplified schema that is to be used by EE 296 teams for Spring 2016. | ||
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| - | <code> | ||
| - | typedef struct { | ||
| - | uint16_t schema; // Schema Identification Number | ||
| - | uint16_t address; // Address of the particular node | ||
| - | uint32_t uptime_ms; // Time since start of program | ||
| - | uint16_t batt_mv; // Battery Voltage (in milli volts) | ||
| - | uint16_t panel_mv; // Panel Voltage (in milli volts) | ||
| - | uint32_t bmp185_press_pa; // Pressure Value (in pascals) | ||
| - | int16_t bmp185_temp_decic; // Temperature Value (in celsius) | ||
| - | uint16_t humidity_centi_pct; | ||
| - | uint16_t apogee_w_m2; | ||
| - | } schema_296; | ||
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| - | </code> | ||
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| - | ^ Name ^ Size (Bytes) ^ Description ^ | ||
| - | | schema | 16 | Packet schema version. You should set this in software before you send the packet - this field is used by the server to identify your packet number. For the 296 weatherbox, set this to 296. | | ||
| - | | address | 16 | The address of your particular node. This address is assigned by the lab and is unique to every weatherbox. | | ||
| - | | uptime_ms | 32 | The uptime in ms. This shows how long the microcontroller has been on for. | | ||
| - | | batt_mv | 16 | Battery voltage in millivolts. This is used for diagnostic purposes. | | ||
| - | | panel_mv | 16 | Panel voltage in miliivolts. This allows us to monitor the voltage of the solar panel. | | ||
| - | | press_pa | 32 | Pressure in pascals - uses the (bmp085). | | ||
| - | | temp_decic | 16 | Temperature in deci-celsius - uses the (bmp185). | | ||
| - | | humid_centi_pct | 16 | Humidity in centi percents. | | ||
| - | | solar_irr_w_m2 | 16 | Solar Irradiance. Taken from the apogee reading.. | | ||
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| - | In the interests of time, this packet is simplified from the original weatherbox specification. In this specification there are no varying sample rates for each data type - one packet gives you one sample point for each data type. | ||
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| - | ===== Converting from volts to w_m2 ===== | ||
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| - | Make sure you convert your voltage reading from the apogee sensor to watts per meter squared ($w/m^2$). We're measuring solar irradiance: https://en.wikipedia.org/wiki/Irradiance | ||
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| - | You can find the conversion factor on the apogee website for your specific sensor, but here is what it should be: | ||
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| - | $Conversion Factor = (4.0mV) / (1 w/m^2)$ | ||
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| - | Therefore: | ||
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| - | $X (watts/m^2) = V_{sensor} / (0.004V)$ | ||
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| - | ====== Schema v1 ====== | ||
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| - | This the initial data format for the weatherbox. You can see the data packet represented as a struct in the C programming language. | ||
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| - | <code> | ||
| - | typedef struct { | ||
| - | uint16_t schema; | ||
| - | uint16_t address; // Address of Arduino | ||
| - | uint32_t uptime_ms; // Time since start of program | ||
| - | uint8_t n; // number of data points in packet 0..30 | ||
| - | uint16_t batt_mv[15]; // Battery Voltage (in milli volts) | ||
| - | uint16_t panel_mv[15]; // Panel Voltage (in milli volts) | ||
| - | uint32_t bmp085_press_pa; // Pressure Value (in pascals) | ||
| - | int16_t bmp085_temp_decic; // Temperature Value (in celsius) | ||
| - | uint16_t humidity_centi_pct; | ||
| - | uint16_t apogee_w_m2[60]; | ||
| - | } schema_1; | ||
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| - | </code> | ||
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| - | ^ Name ^ Size (Bytes) ^ Description ^ | ||
| - | | Schema | 16 | Schema version | | ||
| - | | Address | 16 | Address number of the node | | ||
| - | | Uptime | 32 | Uptime in milliseconds | | ||
| - | | Data Points | 8 | Number of data points | | ||
| - | | Battery Voltage | 16 | Battery voltage in millivolts | | ||
| - | | Panel Voltage | 16 | Panel voltage in miliivolts | | ||
| - | | Pressure | 32 | Pressure in pascals | | ||
| - | | Temperature | 16 | Temperature in celsius | | ||
| - | | Humidity | 16 | Humidity | | ||
| - | | Solar Irridance | 16 | | | ||
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| - | ====== Schema v3 ====== | ||
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| - | This is the packet used for apple. | ||
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| - | <code> | ||
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| - | typedef struct { | ||
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| - | uint16_t schema; | ||
| - | uint16_t address; // Address of Arduino | ||
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| - | uint8_t overflow_num; // Number of times millis overflowed | ||
| - | // (happens ~every 49 days) | ||
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| - | uint32_t uptime_ms; // Time since start of program | ||
| - | uint8_t n; // number of data points in packet 0..30 | ||
| - | uint16_t batt_mv[6]; // Battery Voltage (in milli volts) | ||
| - | uint16_t panel_mv[6]; // Panel Voltage (in milli volts) | ||
| - | uint32_t bmp085_press_pa; // Pressure Value (in pascals) | ||
| - | int16_t bmp085_temp_decic; // Temperature Value (in celsius) | ||
| - | uint16_t humidity_centi_pct; | ||
| - | uint16_t apogee_w_m2[20]; | ||
| - | } schema_3; | ||
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| - | </code> | ||