ANT Forum

Hi,
I am trying to have two people wearing Garmin HR monitors and pedaling a bike in the same room at the same time and getting their data recorded in two different computers with USB ANT+ dongles, but so far I can only get both computers to display the data coming out of one of the hr monitors and one of the cadence sensors.

Is what I am trying to do even possible?
Is there anyway of exclusively pairing the sticks/computers to each of the hr monitors and cadence sensors?

Thanks!      

Hi!

You can't manage pairing through the ANT+ USBs but you should be able to do so via the software you are using to manage the connection.

What software are you using on the PCs to receive from the sensors?

Thanks,

Kat      

Thanks Kat,
we built our own software in C# using the ANT_NET.dll v2.3.0.0, based on an example online.
Our application reads cadence and heart rate based on a config file specifying the type of ANT device, number of device, type of transmission and channelperiod.

//For our cadence sensor
devicetype = 121
devicenum = 0
transtype = 1
channelperiod = 8086

//For our hr monitor
devicetype = 120
devicenum = 0
transtype = 1
channelperiod = 8070

We use the same app and config file in both computers. I wonder if each cadence sensor and hr monitor have a unique not changing devicenum I can hardcore to "pair them" by software to a specific computer.      

Your "devicenum=0" is in fact a wildcard, meaning: pair to any device of the correct type and transmission mode that's near.
ANT devices are supposed to have "nearly unique" device nums. Well, as the number space is very limited, they aren't really unique, but there's a fair chance that no double device nums are close to each other.

So display devices usually force a pairing procedure like:
1. tell the user "bring exactly one sensor close to me and ensure that it's switched on"
2. try to connect using the 0 wildcard
3. if a sensor is found, take it's device number from the responses and
4. save that for further connects - that now use this non-zero number instead of the wildcard

All this should however be explained in the basic ANT documents.

Cheers,
OMB      

Thank you, the device number did the trick.
I ended up listing all my hr monittors' and cadence sensors' user_devicenum one by one with a simple app and writing down the ones I wanted to use in a config file from which my application is reading.
I was finally able to do what I needed.
Thanks!