JSON Performance on Forerunner 735XT

Former Member over 8 years ago

Hello,
I have developed a small application with monkey c, which requests data from a webservice via the Comm.JsonRequest call. Everything works fine, but depending on the amount of data it needs a long time, until data is received in the callback function.
In detail: if the json-data has a length of 150 bytes, it takes about 2 seconds, with 1500 bytes it takes about 12 seconds. I am using the 735XT together with an iPhone 6.
Using the simulator, there is no significant difference between small and big json data.

In addition, the performance seems not to depend on the complexity of the json-structure. Even with a flat structure (one value with a short or long text field) the mentioned times on the 735XT still resist.
The speed of the internet connection of the iPhone cannot be the reason. I tested it multiple times in different WLANs as well as 4G.
Is this a firmware problem, or does somebody know a work araound for this behavior?

Regards, garwuem

jim_m_58 over 8 years ago

the speed in the sim will always be much faster than on a real watch. And the slowdown you see is likely the BLE between the phone and the watch, but could also be impacted by the speed of the data connection to your phone.

But you'll never get the speed you see in the sim. Just the internet speed could be far greater on a pc than a phone, and the BLE also isn't involved.

Former Member over 8 years ago

And the slowdown you see is likely the BLE between the phone and the watch, but could also be impacted by the speed of the data connection to your phone.

But you'll never get the speed you see in the sim. ...

According to my tests, the slowdown means a communication performance of 10 seconds for about 1300 Bytes. That results in 130 bytes per second over the BLE connection.
I have expected a bit more speed.

The performance of the watch for computing and displaying the received data is quite ok. There is no visible difference between the small and the large JSON response.