I'm replying "Low-cost DIY underwater modem using COTS components and Unet audio" but when I set:
phy[1].fmin = 4700
got:
WARNING: Parameter fmin set to 6000.0
so I can't set fmin to 4700 as in article.
I am using Raspberry Pi 4 with unet community 3.1. I haven't the 'underwater speaker' but before to buy I want to be sure that the software is fully functional. I have tested two Raspberry in air and the command 'tell' and 'ping' works.
It depends on 3.1 old community version? Thanks
The default unet audio band is 6-18 kHz since the baseband carrier frequency is set to 12 kHz and the baseband sampling rate is set to 12 kSa/s. If you keep to this band, things are simple.
You can change the band in the etc/modem.conf by updating the fc setting (which is used for both, baseband carrier frequency and sampling rate). However, if you do that, the default settings for all the phy parameters may not be appropriate, and you may have to adjust those too.