Timbatao wrote: ↑
Fri Sep 14, 2018 8:45 am
I am working to the diving company, and we have coms for surface supply diving. They are expensive and breaking down so often like raining in Scotland....
However, I got the idea to make coms with raspberry PI.
Problem is I am not experienced with PI, but however, i know blibs and blobs about Linux and basic electronics.
But i think it is not so much complicated because you need:
2 audio inputs
1 video input
We would use existing com box and some features.
Maybe by any chance, anyone would help me to start with this and give me some advice?
I wonder why the existing communications boxes keep breaking.
It appears to be a two channel analogue mixer in a weatherized box with talk back feature. Since the analogue circuitry needed to implement such a device is well understood, perhaps the box isn't as weatherized as it appears. The next time you put one back together, it might be prudent to squirt a little silicone caulk around the seams before tightening down the screws. Do you use batteries with the device? That could be another point of failure.
As you seem to be looking for a Pi project, one could ask what good could a Pi be for a surface supply diving enterprise?
As you may already know, the Pi is a real computer designed for teaching children how to program that has been appropriated by hobbyists to build IoT devices for home use. The resulting reliability of each project varies with the skill of the maker. However, most of the benefits come not from reliability but from flexibility and originality.
Unfortunately, the Pi doesn't have built-in analogue inputs. While the forums are full of people asking for more RAM and faster USB ports in order to duplicate the functionality of a desktop computer, what makes the Pi interesting is that it is not a desktop computer but more of an up in a balloon, around in a robot type of device. In my opinion, an important feature the Pi missing in this regard is built-in analogue to digital converters that could be used as audio inputs, joystick interfaces and for various sensing and control applications. Just like GPIO, having analogue inputs would open doors to many people who don't have the resources to design or purchase add-on hardware for each project and experiment. Making such hardware built-in would also lead to standardisation and focus for the community.
Back on topic, the Pi does have built-in audio outputs, so it would be easy to turn a broken communications box into an internet radio that could be placed in the office or home as a conversation piece. It also has a built-in camera interface with matching camera which could be used to monitor operations at the surface for training and analysis. With a USB microphone and audio input dongle, communications from the audio output of a working analogue communications box could be recorded as well. Making either of these last two ideas reliable will likely be surprisingly difficult.
While audio hardware along with digital mixing software could, in theory, be used to replace the entire communications box, the result would likely have the audio quality of a satellite telephone connection from India to Mexico, whereas, the analogue solution you are currently using introduces almost no latency or lag and should be more reliable.