There have been a few posts on this issue without any solutions announced.
Wanting to access internal movesense sensor data (ECG, Acc…) but without using the Android or iOS platforms ( as suggested by a movesense presentation https://www.movesense.com/wp-content/uploads/2018/11/2018-11-06-Using-Movesense-CustomGATTService.pdf ), I have failed to do so for at least 1 week. I can successfully create my own GATT characteristics and subscribe to them from outside the movesense device. This is easily done by augmenting the samples/custom_gattsvc_app with a few lines :
- Definition :
const uint16_t myCharUUID16 = 0x2A58; // this new characteristic will appear in the service as the third one in the sample
- In CustomGATTSvcClient::configGattSvc() :
WB_RES::GattProperty myCharProp = WB_RES::GattProperty::INDICATE;
myChar.props = wb::MakeArray<WB_RES::GattProperty>( &myCharProp, 1);
myChar.uuid = wb::MakeArray<uint8_t>( reinterpret_cast<const uint8_t*>(&myCharUUID16), 2);
customGattSvc.chars = wb::MakeArray<WB_RES::GattChar>(characteristics, 3); // 3 here since there are 3 characteristics now
- Accessing You can now see and subscribe with a BTLE client (bluetility…) to the new service even if it does not do anything for now.
The problems start here for me :
In CustomGATTSvcClient::onGetResult() I try to force a subscription to ECG or Acc since onGetResult() is called by CustomGATTSvcClient::onPostResult() once all the BT services are created :
int32_t sampleRate = 10;
asyncSubscribe(WB_RES::LOCAL::MEAS_ACC_SAMPLERATE(),AsyncRequestOptions::Empty, sampleRate);
I do not implement onSubscribeResult()
In onNotify() you should be able to intercept the call from the whiteboard with the new data every 1/10 second by
switch (resourceId.getConstId()) {
case WB_RES::LOCAL::MEAS_ACC_SAMPLERATE::ID:
{
// To see a blinking LED on each new Acc data
asyncPut(WB_RES::LOCAL::COMPONENT_LED(),AsyncRequestOptions::Empty, myFlippingBool);
myFlippingBool = ! myFlippingBool;
}
What I have observed :
A. When I asyncSubscribe() the ECG or Acc, the sample’s WB_RES::LOCAL::MEAS_TEMP::LID is no longer called and no updates are dispatched to a BT client even after a successful subscription to the 0x2A1C characteristic. This means that all Notifications are disabled by a resource conflict ?
B. When subscribing ( as before ) or even by :
wb::Result result = getResource("Meas/Acc/10", mMyAccResourceId);
result = asyncSubscribe(mMyAccResourceId);
The onNotify() method is never called as the LED does not blink ( even directly after onNotify() implementation without the switch / case )
There is a lack of documentation on CustomGatt and it seems it blocks many people in integrating the sensor on other platforms ( Raspberry Pi or generic processors running a BT stack ). I have tried before to access the movesense platform with direct AT commands from a rudimentary microcontroller and a BT module without success (Movesense direct access to GATT endpoints ), so now I’m turning to a Raspberry solution + Qt without success.
Thank you for any example or answers to this question !
