smartphone - pressure sensors - sensors

I am not very clear whether the pressure sensor available in android is used to measure the atmospheric pressure or the pressure on the touch screen?
(getAltitude()/ event.getPressue() )
Do we have any such pressure sensor in iOS which could give us values of atmospheric/finger pressure?
Any help appreciated,

event.getPressure() measures finger pressure on the touchscreen: http://developer.android.com/reference/android/view/MotionEvent.html#getPressure(int)
getAltitude will give you your geo altitude: http://developer.android.com/reference/android/location/Location.html
I don't know about iOS.

Related

Qwiic BME280 pressure reading too high?

I'm using sparkfun BME280 sensor to collect atmospheric data. temperature & humidity readings are correct but pressure reading is too high. I used another sensor for getting pressure which returns normal reading like 1000hpa while BME280 returns 1180hpa. it's too high. I am using python library and set the pressure_oversample value according to the example written on document(https://qwiic-bme280-py.readthedocs.io/en/latest/ex4.html) but still getting high value. how can I get correct pressure reading?
I don't know if this is relevant in your case, but the Adafruit BME280 library has an adjustment for your location's pressure at sea level:
bme280.sea_level_pressure = 1013.25

bluefruit NRF52 max connection interval speed (connInterval)

I've got an Adafruit Bluefruit NRF52 hooked up to the Adafruit BNO055 9-axis orientation sensor, gathering 3 axis of absolute orientation plus 3 axis of acceleration (6 floats in total) and sending over Bluetooth through bleuart. I need the bleuart to update every 7.5 milliseconds with a new line of values, but when I run it, it doesn't print more than about 20 lines new lines of values every second. Essentially I need values to update as quickly as possible, as I am measuring very high speed, high fidelity movement.
At the start of each line I also have three digit number, which represents the calibration status of each sensor on the IMU. Each printed line looks something like:
303 68.69 4.19 -2.19 -0.12 0.14 -0.40
I am currently streaming to my iphone with the latest iOs version, which in theory can handle 7.5ms intervals.
I've read that a solution may be to buffer the values and send over in a larger chunk at larger connection intervals, but am unsure on how to do this.
My relevant Arduino code is below:
Bluefruit.setConnIntervalMS(7.5, 20);
void loop()
{
imu::Vector<3> accel =
bno.getVector(Adafruit_BNO055::VECTOR_LINEARACCEL);
/* Get a new sensor event */
sensors_event_t event;
bno.getEvent(&event);
/* Display the floating point data */
bleuart.print(event.orientation.x);
bleuart.print("\t");
bleuart.print(event.orientation.y);
bleuart.print("\t");
bleuart.print(event.orientation.z);
bleuart.print("\t");
/* Display the floating point data for Linear Acceleration */
bleuart.print(accel.x());
bleuart.print("\t");
bleuart.print(accel.y());
bleuart.print("\t");
bleuart.print(accel.z());
bleuart.print("\n");
}
iOS doesn't actually support a 7.5ms connection interval. Check the connection parameters section (11.6) in the Apple developer guidelines. Just because you are specifying a CI that low doesn't mean that you'll actually get it. In this scenario the nRF52 is the slave and only requests an interval that low from the master (your phone). The master, if it so wishes, can completely disregard the request you make.
You'd be better off, as you've already eluded to, buffering your data and sending it via a custom characteristic. Figure out how many bytes you need and maybe you can pack a couple of readings into a single BLE write. If you're really struggling with throughput then you'll need a custom service with multiple characteristics. I recently worked on a project that streams 8 channels of data (~125Hz/16-bit) over BLE with three characteristics and this is bordering on the maximum throughput you can achieve.
As an aside: judging data throughput by the amount of lines printed per second is a big no no. Print functions typically have huge overheads and will drastically affect your measured throughput in a negative way.
Let me know if I can help further.

FPGA implementation of temperature sensor data in 7 segment display

I want to know about project related to temperature sensor , like the temperature 80 degrees is sensed the it will send signal to FPGA and it should display "error" into seven segment display. and temperature sensor is connected to one machine and FPGA is connected to the generator, both the machines are connected to each other though for supply voltage. how to integrate both?? Please help...

How to Increase Mic sensitivity

I am new to android.I am trying to capture very low volume sound .I want to know how can I increase sensitivity of the mic of my phone. Thanks in advance

Read Data from unknown Bluetooth Device while communicating

I am trying to figure out how the FORA d15b blood pressure monitoring system communicates via Bluetooth. I want to be able to eventually write an Android app that can receive blood pressure data from the device.
More specifically, I want to know the exact data to send to the device in order to request blood pressure information. I also want to know the data that the device sends out. However, I don't even know the format of the data being sent/received.
I know that FORA has a PC app that can communicate with the d15b device via Bluetooth but I don't know what information its sending/receiving over Bluetooth, and that's what I want to know.
Here is Bluetooth information I know about the d15b device:
Bluetooth Carrier Frequency: 2400MHz to 2483.5MHz
Bluetooth Modulation Method: GFSK, 1Mbps, 0.5BT Gaussian
Transmission Power: +3dBm to –20dBm; Power control 4 stage
Receiving Signal Range: -88dBm to -20 dBm
Receiver IF Frequency: 1.5MHz center frequency
Maximum Data Rate: Asynchronous:723.2kbps/57.6kbps;
Synchronous: 433.9kbps/433.9kbps
I'm struggling to even find a starting point. Any help is appreciated! Thanks in advance.
I am familiar with C, Java, and Arduino if that helps at all...
NOTE:
Unfortunately, I am new to Bluetooth. After doing some research, I am still pretty clueless on how to solve this problem. In the title, I say unknown Bluetooth device because I just want to be able to read what I/O of an unknown Bluetooth device, which in my case happens to be the d15b that I know nothing about. Sorry if the question has been addressed already or if this is an inappropriate place to post this question. I wasn't sure.
Bluetooth data is encrypted. So it's not possible to hack it easily.
Forget it.

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