USB-interface for DiveRite/Tusa/Apeks/Cressi

[dexter98]

No, not yet, so please DO NOT BUILD THIS SCHEMATIC yet! It might contain errors and may even (although unlikely) damage your divecomputer.

Besides, I have also designed a PCB layout for it, if you can make PCBs yourself. I want to publish that layout after I have tested the interface.

Below, I have reattached the picture above, since it is not working properly.

 

[dexter98]

!!! GOOD NEWS !!!

IT WORKS!!!


I have built the serial interface on veroboard, connected it to the altered USB-to-serial interface and tested it with an Apeks Quantum dive computer. And yes, it works!

I have tested the interface with the Apeks software (and therby very probably also with the TUSA-software and Cressi-Sub software) and the Dive Rite software and it works with both software!

Although it is working and thereby the concept is working, I have also tested this interface with a scope and it's not completely within the specs and will give problems with some pc's/usb-to-serial interfaces. I'm working on this now to tweak it a bit more for optimal performane. If this is done and I have built it on a real PCB, I'll publish the resulting schematic and PCB layout.

Below you can find 2 pictures of the test setup.

 

[dexter98]

Currently, I'm working on the following improvements:

1) In the above tests, an additional 9volts battery was included, since (unlike the serial version of the pc-software) no positive power is available on the serial output. This is mainly a software problem, since the new interface (not yet published) does work correctly when tested with HyperTerminal, even on a USB-to-serial converter.

2) The serial output of the interface is not actively pulled low. This might give problems on some pc's / USB-to-serial converters. I'm working on an improved output circuitry.

3) Improved output protection.

 

[Hanssing]

Currently, I'm working on the following improvements:

Thats very impressing - keep up the good work.

Its not really relevant for me, since I allready have the cable, but would be a fun project for others.

Only problem left is the high failure rate of the computers :huh:

Nicolai

 

[dexter98]

Does anyone know if this relative high failure rate is specific for the Apeks computers, or do the Cressi, TUSA and DiveRite computers fail as often as the Apeks?

If might be interesting to buy the Cressi for instance, if they have solved that problem in the Archimede II.

 

[RisingPhoenix]

I have over 50 hours on my Archimedes II now both recreationally, and using 2 mixes, and it hasnt missed a beat, however, 50 hours is not a huge amount, and for AUD$500 its hard to go past for a 2 mix computer!!!

Cheers,

Steve

 

[jigo]

thanks for the link. problem is i cant read japanese....

 

[cayoo]

Hi from France !

You guys seem to be the only ones trying to work this interface out.

I recently bought an ARCHIMEDE II (7 dives ago), hoping that you'll be able to publish a DIY for the USB interface...

Thank you sooooooooo much for your great work !

Stef

 

[dexter98]

I have solved the 3 problems above. The interface should also work now directly on an USB cable without any external batteries.

Now I'm finalizing the design (both schematic and also a PCB) and hope to publish the results soon.

For the Cressi Archimede II, you only need the serial interface itself, since the Cressi-software can connect directly to a serial port. But please wait until I have published the final result, since the 'old' schematic contains a few errors.

 

[dexter98]

The documentation is as good as ready. The last step is to etch the PCB and test if it is working correctly. I'll hope to do that tomorrow and present you the final results at the end of this week!!!