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How to interpret data coming from the pedometer device

Posted: 09:40, 12 Jun 2015
by wiserus
I have a pedometer device that I can connect to and read services, characteristics an attribute data.
Can someone help me understanding how to interpret the data coming from the device
I have following code that reads data in to the Uint8Array array. Individual -

Code: Select all

            // Get data for each service
            console.log('number of services ' + device.__services.length)element of an array shows an integer. I dont know this is a right way to access data. If yes, what those individual array element values mean?


            console.log('number of characteristic ' + device.__services[0].__characteristics.length)
            {
                //var characteristic = service.__characteristics[characteristicUUID]
                device.readCharacteristic(
                     device.__services[0].__characteristics[0]['uuid'],
                     function (data) {
                         var test = new Uint8Array(data);

                         var result = "";
                         for (var i = 0; i < test.length; i++) {
                             console.log('data  element is ' + test[i]);
                             console.log('data  element string is ' + String.fromCharCode(parseInt(test[i], 2)));
                             result += String.fromCharCode(parseInt(test[i], 2));
                         }

                         console.log('data  is ' + result);
                     },
                     function (errorCode) {
                         console.log('BLE readCharacteristic error: ' + errorCode);
                     });
            }

Re: How to interpret data coming from the pedometer device

Posted: 22:49, 08 Jul 2015
by ardiri
what does the data actually look like?
what is the model of the pedometer you are using?

with this information; it may be possible to find some data specifications and then be able to figure out how to interpret the data.

Re: How to interpret data coming from the pedometer device

Posted: 21:39, 30 Nov 2015
by zdravko
Hi!
Did you manage to read data from fitbit chargeHR bracelet, or any other BLE pedometer for that matter?
BLE Discovery finds the device, shows it services, and I am missing the interpretation.
Best regards, Zdravko.

Re: How to interpret data coming from the pedometer device

Posted: 17:19, 02 Dec 2015
by Fredrik
Without a list of Service and Characteristic UUIDs, I can only guess.

Your device might be running the Running Speed and Cadence service, UUID 0x1814. The most interesting characteristic there would be the RSC Measurement.

I hear the FitBits are special though; don't use standard services. There's a Python program called "Galileo", which is said to be able to talk to Blueooth FitBits, but I could not parse the code well enough to find any data interpretations. Maybe you'll have more luck.

Re: How to interpret data coming from the pedometer device

Posted: 17:31, 02 Dec 2015
by zdravko
Here is console log of the Evothings BLE Discovery app, that I would like to use.
It contains a list of services and characteristics form ChargeHR device.
Unfortunately, I need to learn much more to be able to read this...

Code: Select all

LOG: connect(C4:4A:0D:E4:8D:F4)
LOG: connect 2 state 2
LOG: connected, requesting services...
LOG: s1: 0 00001800-0000-1000-8000-00805f9b34fb. 3 chars.
LOG:  c7: 00002a00-0000-1000-8000-00805f9b34fb. 0 desc.
LOG:   properties: PROPERTY_READ
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:  c8: 00002a01-0000-1000-8000-00805f9b34fb. 0 desc.
LOG:   properties: PROPERTY_READ
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:  c9: 00002a04-0000-1000-8000-00805f9b34fb. 0 desc.
LOG:   properties: PROPERTY_READ
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG: s2: 0 00001801-0000-1000-8000-00805f9b34fb. 1 chars.
LOG:  c10: 00002a05-0000-1000-8000-00805f9b34fb. 1 desc.
LOG:   properties: PROPERTY_READ PROPERTY_INDICATE
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:   d19: 00002902-0000-1000-8000-00805f9b34fb
LOG: s3: 0 adabfb00-6e7d-4601-bda2-bffaa68956ba. 4 chars.
LOG:  c11: adabfb04-6e7d-4601-bda2-bffaa68956ba. 1 desc.
LOG:   properties: PROPERTY_READ PROPERTY_NOTIFY
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:   d20: 00002902-0000-1000-8000-00805f9b34fb
LOG:  c12: adabfb02-6e7d-4601-bda2-bffaa68956ba. 0 desc.
LOG:   properties: PROPERTY_READ PROPERTY_WRITE_NO_RESPONSE
LOG:   writeType: WRITE_TYPE_NO_RESPONSE
LOG:  c13: adabfb03-6e7d-4601-bda2-bffaa68956ba. 1 desc.
LOG:   properties: PROPERTY_READ PROPERTY_NOTIFY
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:   d21: 00002902-0000-1000-8000-00805f9b34fb
LOG:  c14: adabfb01-6e7d-4601-bda2-bffaa68956ba. 1 desc.
LOG:   properties: PROPERTY_READ PROPERTY_NOTIFY
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:   d22: 00002902-0000-1000-8000-00805f9b34fb
LOG: s4: 0 558dfa00-4fa8-4105-9f02-4eaa93e62980. 1 chars.
LOG:  c15: 558dfa01-4fa8-4105-9f02-4eaa93e62980. 1 desc.
LOG:   properties: PROPERTY_READ PROPERTY_NOTIFY
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:   d23: 00002902-0000-1000-8000-00805f9b34fb
LOG: s5: 0 0000180a-0000-1000-8000-00805f9b34fb. 2 chars.
LOG:  c16: 00002a29-0000-1000-8000-00805f9b34fb. 1 desc.
LOG:   properties: PROPERTY_READ
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:   d24: 00002904-0000-1000-8000-00805f9b34fb
LOG:  c17: 0000fb00-0000-1000-8000-00805f9b34fb. 0 desc.
LOG:   properties: PROPERTY_READ
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG: s6: 0 0000180f-0000-1000-8000-00805f9b34fb. 1 chars.
LOG:  c18: 00002a19-0000-1000-8000-00805f9b34fb. 1 desc.
LOG:   properties: PROPERTY_READ PROPERTY_NOTIFY
LOG:   writeType: WRITE_TYPE_DEFAULT
LOG:   d25: 00002902-0000-1000-8000-00805f9b34fb

Re: How to interpret data coming from the pedometer device

Posted: 18:11, 02 Dec 2015
by Fredrik
Definitely a Fitbit device. I've searched as far as I can, but they don't seem to like anyone except their own apps talking BLE with their devices.
The only way to get data from a Fitbit device is via the Web API <https://dev.fitbit.com/docs>.

Re: How to interpret data coming from the pedometer device

Posted: 08:36, 03 Dec 2015
by zdravko
Obviously, Fitbit won't work. How about any other pedometer? There are many different manufacturers, while it seems there are just a few Fitbits.

Re: How to interpret data coming from the pedometer device

Posted: 10:19, 03 Dec 2015
by Fredrik
Like I said, I would hope they're running the standard Running Speed and Cadence service. They might also provide the Heart Rate and Pulse Oximeter services.