Before you can connect your ANT+ Garmin Device to your tablet / phone, you need to install some additional piece of software and set up a few things in your watch. Here is a detailed explanation of each step.
Step 1: check your ANT+ USB key
A small number of Android devices (mostly the Sony Xperia family) come with an internal ANT+ chip. In this case, you don't need the Garmin USB key. In every other case, you need the ANT+ USB key that you're already using with your computer. Before you go further, check the key version on the bottom: it should read USB2. USB1 keys are not supported at this time.
Step 2: install the ANT+ services
In the end, I decided to base Sportablet on the ANT+ services from Dynastream. Unlike the Garmin ANT+ Agent you install on your PC, those ANT+ services don't know about your Garmin device, but know about the ANT+ hardware (the USB key, the internal chip on Xperia, etc). This should make my app a bit more future-proof (read: I shouldn't have to implement low-level drivers for new keys). We'll see :-). Meanwhile, that means you have to install two free apps (Android services actually) from Google Play:
- The ANT Radio Service
(which deals with ANT+ channels)
- The ANT USB Service
(which deals with the USB key). If you have an internal ANT+ chip (like the Xperia) you don't need this. See here
for details on using an Xperia. Go ahead and do it! Note that those apps require your Android device to be properly classified by Google Play as one with USB Host capabilities. Some devices, which are host-capable, are not properly classified in Google Play. In that case, unfortunately, the ANT+ services will result "incompatible" with your device and you won't be able to download them. As they're provided by Dynastream, there is little I can do about it - you'll have to find an alternative way to obtain and install the APK (or convince Dynastream to drop the USB HOST requirement from their manifest, as I did for Sportablet).
Step 3: check that everything works
Insert your USB key. If you have a micro-usb connector, remember that you need to use a USB OTG adapter. This dialog should pop up from the ANT+ Service:
of course, you have to accept.
If the dialog does not pop up, your USB key is not being recognized by the ANT+ Service. That's not part of Sportablet, so I can't really help you much on this side. Please check the Google Play page for the two ANT+ Service apps, as there are quite a few hints from users in the comments section.
Now, if you want to double-check
that it works, and you have a chest strap that you use with your Garmin, you can also download the free ANT+ Demo
from Dynastream. It's a simple app that can connect with a chest strap or a scale and show you some values (it won't connect with your Garmin, just with the HR belt). If the ANT+ Demo works, everything has been set up properly. If you don't have a chest strap, just skip this step.
Step 4: configure your watch
It's time to fiddle with the bezel a little and make sure ANT+ is properly set up. Although you've probably done this before to pair your Garmin with your PC, you have to do this again to enable pairing with your Android device, and to make sure that all the activities in your watch will be sent. The following pics are based on a Forerunner 405.
Choose Settings > ANT+ > Computer
Make sure that:
Enabled is set to yes
Pairing is set to on
Force Send is set to yes
Note: the watch will change "force send" to "no" after any successful upload. If you upload from your Garmin to more than one device (like your tablet + your pc), you have to set it back to "yes". The Garmin does not remember to which device it has sent data, and by default it is only sent once.
Step 5: it's time to run Sportablet!
Run Sportablet. Don't click on Get new yet. First, make sure that your watch is not in stand-by, by clicking the top button. I've found that the watch transmits more reliably while in Time mode:
Now click the Get new button. You may see that the app is trying to connect on different frequencies: that's ok as it's part of the ANT+ protocol. After a while, the app will ask you to accept pairing on your device:
do so by clicking the top button on your watch. After that, it should proceed as usual: Runs are downloaded, then Laps, then Tracks. At the end, the dialog will report how many new activities you got. Click Done to get back to your main screen. Don't forget to send me a log, thanks!
NOTE: if you're using an Xperia or another device with internal ANT+ chip, remember to click options, and set "Force ANT+ scan" on. This will force the app to try using the internal chip.
Tweaking : )
ANT+ has very delicate timings, which can be easily disturbed by background processes, especially in a smartphone. So if you experience problems, the first thing you should do is turn off the GPS, Bluetooth, WiFi, data connection on your phone. This is known to help a lot.
ANT+ is not particularly good at transferring long sequences of data, and the protocol Garmin adopted on top of it for the 405/410 family does not allow to retry on failures, so the combination is a little flaky on some devices. If you have any problem downloading long activities, Sportablet and the Uploader provides a few settings that you can try (under "options")
- First, make sure that diagnostics is turned off. ANT+ is very time sensitive, and on some devices even the time spent on logging seems to cause problems.
- Next, just enable "Delay Ack". Leave all the other ANT+ options off. This should give the watch a little more time to synch with the tablet during long bursts.
- If that still fails, turn "Delay Ack" off and set "Boost TX power" on.
- If it keeps failing, leave those on and set "Delay Ack" on as well.
- If you still have problems, get in touch.