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en:iot-open:practical:hardware:sut:stm32:emb1b_1 [2024/04/21 08:30] – [Suggested Readings and Knowledge Resources] ktokarzen:iot-open:practical:hardware:sut:stm32:emb1b_1 [2024/04/21 09:41] (current) – [FAQ] ktokarz
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 ==== Start ==== ==== Start ====
-For statical measurements, ensure the fan is stopped. Note that the fan tends to spin up on itself (explained in EMB1A) when the GPIO controlling the fan is not configured, so it is better to ensure it is set to output and low (0) to keep the fan stopped. Refer to the [[en:iot-open:practical:hardware:sut:esp32:emb1a_1|]] for details on controlling the fan.+For statical measurements, ensure the fan is stopped. Note that the fan tends to spin up on itself (explained in STM1A) when the GPIO controlling the fan is not configured, so it is better to ensure it is set to output and low (0) to keep the fan stopped. Refer to the [[en:iot-open:practical:hardware:sut:stm32:emb1a_1|]] for details on controlling the fan.
  
  
  
 ==== Steps ==== ==== Steps ====
-The steps below present only interaction with the sensor. Those steps should be supplied to present the data (or send it over the network) using other scenarios accordingly, and also with a scenario EMB1A presenting no instructions on controlling the fan that can change the air pressure in the yellow pressure chamber.+The steps below present only interaction with the sensor. Those steps should be supplied to present the data (or send it over the network) using other scenarios accordingly, and also with a scenario STM_1A presenting instructions on controlling the fan that can change the air pressure in the yellow pressure chamber.
  
 === Step 1 === === Step 1 ===
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 The temperature is Celsius, air pressure is in Pascals (so we divide it by float 100 to obtain the hPa reading), and relative air humidity is in % (frequently referenced as %Rh). The temperature is Celsius, air pressure is in Pascals (so we divide it by float 100 to obtain the hPa reading), and relative air humidity is in % (frequently referenced as %Rh).
  
-Note that the controller class has an exciting function of trading Altitude based on the sea-level pressure (needed to have a correct reading:+Note that the controller class has an exciting function of trading the altitude based on the sea-level pressure. We need to provide as the argument the current value of the sea-level pressure to have a correct altitude reading:
 <code c> <code c>
  float altitude = bme280.readAltitude(1013.00F);  float altitude = bme280.readAltitude(1013.00F);
 </code> </code>
  
-You need to know the sea level pressure (a parameter, here, 1013hPa). It uses ''readPressure()'' internally and returns the altitude level. Note that due to the non-linear characteristics of the air pressure drop with increasing altitude, it does not work correctly at high altitudes.+Note that due to the non-linear characteristics of the air pressure drop with increasing altitude, it does not work correctly at high altitudes.
  
 The library also has a mathematical calculation function that returns current sea level pressure if only altitude and local air pressure are known. It does not read the sensor itself, however: The library also has a mathematical calculation function that returns current sea level pressure if only altitude and local air pressure are known. It does not read the sensor itself, however:
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 ===== FAQ ===== ===== FAQ =====
-**I've got NaN (Not a Number) readings. What to do?**: Check if GPIO is OK (should be 47), check if you initialised controller class and most of all, give the sensor some recovery time (at least 250ms) between consecutive readings.+**I've got NaN (Not a Number) readings. What to do?**: Check if the I2C address corresponds to the BME280 sensor (should be 0x76), check if you initialised controller class and most of all, give the sensor some recovery time (at least 250ms) between consecutive readings.
  
 <WRAP noprint> <WRAP noprint>
en/iot-open/practical/hardware/sut/stm32/emb1b_1.1713688247.txt.gz · Last modified: 2024/04/21 08:30 by ktokarz
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