ge0rg
commented
6 years ago The blue bar extending during transmission sounds like a problem (short-cut?) with the audio cable. Normally it only should extend when hearing packets, and that shouldn't happen during transmission.
Maybe the S4 and S7 connectors are different, or the internal audio routing is done in a different way? As I don't have either model, I fear I have no good idea what to suggest.
There were no changes to the AFSK decoder in APRSdroid since 2013, so I think this is really due to hardware differences between your phones.
I do volunteer work with a local school. We recently began yearly high altitude balloon launches using a Byonics tracking radio so we can recover the payloads. Unfortunately, the repeater coverage in our area is a bit spotty and in our two launches so far we have lost contact at about 4000 ft during descent. I've been able to hear the AFSK transmissions on my hand held Baofeng UV-82, but couldn't decode the packets. Using APRSdroid last year in testing on a Galaxy S6 phone, the packets decoded great. This year while preparing for a launch, APRSdroid was very spotty on decoding any packets and when it did, the location reports were still in Mic-E format (which was illegible to me). The connection between the radio and phone was through Baofeng's audio cable which worked great last year. I tried the app on two different phoned this year, both Galaxys one an S4 and the other an S7. The S4 received a few packets, while the S7 never decoded any. On the S7 I could see the blue bar extend across the top of the screen during transmissions, but nothing was decoded. The phones also failed to decode without the cable while using an air gap between speaker and microphones. Experimented with volume control to no avail. Would appreciate any suggestions about solutions or explanations about what might have changed in recent releases to render the app unusable in this way.