Oceanic Geo 2.0 with Tusa USB Cable?

[zhenshi]

Cool, thanks.I think I'll gonna try hooking up a diy cable using this New USB to TTL Serial Cable Adapter FTDI Chipset FT232 USB Cable Computer Cable | eBay with a big plastic peg and some pogo pins embedded first. 3 pins, so there's only 6 possible combinations. if someone has the original Oceanic/Tusa/Aeris cable and also a multimeter and can kindly probe both ends of the cable to confirm which pin is actually the ground pin, that will make it easier

 

[MrChen]

I'd do it for you, but my multimeter broke and I tossed it out. I'm not a big electrical person, so I never replaced it. I seriously bought my cable last week, you should have posted this before that and I could have saved myself some money!

---------- Post added February 19th, 2014 at 09:01 AM ----------

Still very expensive for what is essentially a USB-UART cable with a custom clip connector. I'll hold off the purchase until I've attempted (and fail) to DIY the cable for <$10 first...

It's a complete rip off if you ask me. For whatever reason I thought my computer held 50 dives and I'm coming up on that. Turns out, it only holds 25 and I lost a lot of dives. It's very interesting to see the dive profile in the oceanlog software.

 

[zhenshi]

Found additional info in another forum of someone who has attempted a similar DIY cable before on a Tusa unit, the 3 pins on the computer (from upper to lower) are to be connected to Rx, Gnd, Tx

also the pins are in standard 100mil pitch from rough measurement, so easy to find suitable spring-loaded/pogo pin connectors (e.g. from Mill-Max, Preci-Dip, etc., or maybe even your old cellphones has usable parts).

the PID info in the FTDI chip's eeprom needs to be changed to F460 to match the Oceanic cable, doable with the FT_Prog utility provided by FTDI. so do not buy USB-Serial Uart adapters with non-FTDI chip although they are cheaper.

so there, if anyone wants to attempt to do this as well, you have all the necessary info :cool2:

 

[Divenomad]

mrChen,

FYI, there are two memory chips inside your computer. The log chip, which is accessed only through the dive computers interface which holds a consistent set of data and that memory function is limited to 25 dives. There is no profile information on this memory chip. There is a second memory chip which profile information is downloaded from. There is no set number of dives on this chip, How many dives are recorded depends on the sampling rate that you set on the computer. If you set it at 2 seconds, the you get about 2.5 hours of diving. If you set it for 30 seconds, you will get about 50 hours of diving. This is what is downloaded from the dive computer. It is a completely separate chip from the onboard log, and depending on the dive profile an sampling rate, the information may differ slightly. There is no way to access it other than downloading it. How many dives get recorded is a function of the sampling rate and the length of your dives. I have a considerable amount of expertise on computers built by AUP. If you are having trouble, I'm happy to assist.

I'd do it for you, but my multimeter broke and I tossed it out. I'm not a big electrical person, so I never replaced it. I seriously bought my cable last week, you should have posted this before that and I could have saved myself some money!

---------- Post added February 19th, 2014 at 09:01 AM ----------



It's a complete rip off if you ask me. For whatever reason I thought my computer held 50 dives and I'm coming up on that. Turns out, it only holds 25 and I lost a lot of dives. It's very interesting to see the dive profile in the oceanlog software.

 

[MrChen]

Interesting, thanks. On my first sync, only 25 dives transferred to the computer, so I made the assumption that it just stored 25 dives period.

 

[mlevsky]

Just to confirm what zhenshi has said. Put together a 3.3V FTDI adapter cable (like you'd get from sparkfun) together with a quick bit of veroboard and pin headers. No active (or even passive) components. Works fine - downloaded three dives off the GEO2. Total cost $3 (+ cost of FTDI cable) and about 2 minutes with a soldering iron.

Now all I need is to improve the mechanical connection. Thanks to everyone in this thread for inspiring me to try this.

 

[victorzamora]

Either of you mind typing up a quick How-To on the topic?

 

[mlevsky]

Yep.. It's a touch late tonight and as an Australian, our national religious observance - Test Cricket - is happening, but I'll knock up something over the next day or two.

 

[victorzamora]

That would be fantastic. I think I know how to do it, but electricity is full of magical fairies to me....so I'll order up a USB-to-FTDI cable and await your instruction....after your religious hiatus, of course.

In nomine wicket, et cricket, et bowlingus fasticus.

 

[mlevsky]

Before you go off buying cables - I'm using a 3.3V TTL level cable (https://www.sparkfun.com/products/9717 specifically). FT232 series converter.

I don't have a legit cable to put into a logic analyser, so I can't confirm that 3.3V is correct, other than it actually works , but from other places I've read it appears to be the right level. Note that you can also get cables configured for 5V TTL levels so check your source to make sure it isn't one of them.