I have a Red Board Plus connected to a BME280 via QWIIC. Using example 7 Relative Altitude the code does not understand a keyboard key press to set the local altitude. The code does run, and if I manually change the local pressure in the code, the altitude value changes. However, the code should set the local pressure with a keyboard key press (header in code says).
How should I fix the code to recognize a keystroke?
Marc
I think it will be better if your share the code.
Change the local altitude reference
BME280 Arduino and Teensy example
Marshall Taylor @ SparkFun Electronics
v1.1 by Nathan Seidle @ SparkFun Electronics
May 20, 2015
Feel like supporting our work? Buy a board from SparkFun!
https://www.sparkfun.com/products/14348 - Qwiic Combo Board
SparkFun Atmospheric Sensor Breakout - BME280 - SparkFun Electronics - BME280 Breakout Board
This sketch configures a BME280 to measure height changes, with a button
to zero the local relative altitude.
To use, run the sketch then press a button on the keyboard. The data on the
serial monitor will show zero. Then, move the sensor to a new altitude and watch
how the output changes!
Note: For most accurate results keep the sensor orientation and temperature the
same between measurements.
This code is released under the [MIT License](The MIT License – Open Source Initiative).
Please review the LICENSE.md file included with this example. If you have any questions
or concerns with licensing, please contact techsupport@sparkfun.com.
Distributed as-is; no warranty is given.
*/
#include <Wire.h>
#include “SparkFunBME280.h”
BME280 mySensor;
#include “CircularBuffer.h”
//This is a fixed-size buffer used for averaging data, a software LP filter
//Depending on the settings, the response can be quite slow.
CircularBuffer myBuffer(50);
float localAltitude = 0;
void setup()
{
Serial.begin(115200);
while(!Serial); //Wait for user to get terminal open
Serial.println(“Output a local changing altitude”);
Serial.println(“Press any key to zero local altitude”);
Wire.begin();
if (mySensor.beginI2C() == false) //Begin communication over I2C
{
Serial.println("The sensor did not respond. Please check wiring.");
while (1); //Freeze
}
//filter can be off or number of FIR coefficients to use:
// 0, filter off
// 1, coefficients = 2
// 2, coefficients = 4
// 3, coefficients = 8
// 4, coefficients = 16
mySensor.setFilter(4); //Lots of HW filter
//tempOverSample can be:
// 0, skipped
// 1 through 5, oversampling *1, *2, *4, *8, *16 respectively
mySensor.setTempOverSample(5); //Set oversample to 16
//pressOverSample can be:
// 0, skipped
// 1 through 5, oversampling *1, *2, *4, *8, *16 respectively
mySensor.setPressureOverSample(5); //Set oversample to 16
//humidOverSample can be:
// 0, skipped
// 1 through 5, oversampling *1, *2, *4, *8, *16 respectively
mySensor.setHumidityOverSample(0); //Turn off humidity sensing
//Assume the current reading is where we should start
localAltitude = mySensor.readFloatAltitudeFeet(); //Set reference altitude
for(int x = 0 ; x < 50 ; x++)
myBuffer.pushElement(0); //Clear buffer
}
void loop()
{
//Get the local temperature! Do this for calibration
mySensor.readTempC();
//Check to see if user pressed a button
if (Serial.available() == true)
{
localAltitude = mySensor.readFloatAltitudeFeet(); //Set reference altitude
for(int x = 0 ; x < 50 ; x++)
myBuffer.pushElement(0); //Clear buffer
Serial.read(); //Remove keypress from buffer
Serial.println("Local altitude reset");
}
float reading = mySensor.readFloatAltitudeFeet();
myBuffer.pushElement(reading - localAltitude);
float tempAlt = myBuffer.averageLast(15); //Do an average of the latest samples
Serial.print("Last sample: ");
Serial.print(reading, 2);
Serial.print(" ft");
Serial.print(" Last 15 samples averaged: ");
Serial.print(tempAlt);
Serial.print(" ft");
Serial.println();
delay(200);
}
Check if your settings are like this-
Open the Serial Monitor in Arduino IDE.
At the bottom, set:
Baud rate to 115200 (matches your code).
Line ending to “No line ending”.
Now, press any key (e.g., a, z, 1) and hit Send.
This will reset the local altitude reference as expected.
Thanks, works O.K.
Marc
Good to know that it’s working. To keep the basic info regarding BME280, handy, you can see here. It discusses the intro, pinout, features, specs, features, modes, datasheet and a simplified Arduino code. Introduction to BME280 - The Engineering Projects
Thanks for the link.
Marc