You may encounter connection problems with an ORIGINAL Tentacle and your iPhone, mostly iPhone 6 or 6s. If you are having this problem, please try the following. First connect your Tentacle to your iPhone before you switch it on.
- Make sure you are using the correct cable: a TRRS to TRRS cable, which is available in every well-equipped consumer electronics store
- Check in your phone settings, if the Tentacle app has access to your phone's microphone
- Make sure the volume is set to a level that is high enough. The red volume bar will let you know once you reached a proper level by displaying: Headphone volume OK.
- Your headphone volume might be adjusted. To check, go to Settings > Music > Playback > Volume Limit
- Clean the headphone jack of the phone. Sometimes dirt causes connection issues
- Try to restart your phone
- If nothing of the above works out, there is an Apple 3.5mm to Lighting adapter cable, which is the best solution for that problem
Here are screenshots of an iPhone 12 showing the correct settings: