ANT Forum

I’m using SimulANT+ for testing of HRM sensor in a webapp. I've noticed that sometimes the first broadcast is 8 0x00 in the "ANT Messages" pane. When I investigate the device0 log, this message is never logged. (screenshot : [url=https://drive.google.com/file/d/0B45ATdu5qGEbVElqcTNuUXBxbms/edit?usp=sharing[/url])

I’ve had some trouble with enabling page toggeling detection in the application. It seems like I always get a previous session broadcast (first two payload bytes 0x00) before the first broadcast in the new session. To debug the issue I installed wireshark to listen for the raw usb traffic between the ANT-2 (3.1) master and the ANT-m (4.1) slave in RX scan mode. [url=https://drive.google.com/file/d/0B45ATdu5qGEbMVY1cWRBSUpZa0U/edit?usp=sharing[/url]). (SimulANT+ Timestamp 49950171 corresponds to frame 355 in wireshark log). I’ve highlighted the message that I think is a previous broadcast that’s sent before the first simulated broadcast.

On the receiving side I’m filtering the first few broadcast when a new master is discovered to account for previously old data before starting page toggeling detection.

Is it possible for SimulANT+ to set broadcast data before opening the channel to avoid sending what seems like a previous buffered broadcast?      

It is possible - we will file a bug for this issue and fix it for the next release.

Note however that it is not guaranteed that all sensors in the market will do this. Most displays typically would have taken a few seconds to acquire the sensor, and this issue would not have been noticed, however, since USB-m includes high duty search, that is why you are able to see that first transmitted message.