HighPressureLogger, Odometer/ Re: Which protocol to implement on a home brewed diving computer ?

Thomas Schrein (mailinglists) tsx508 at schrein.de
Thu Mar 19 10:30:58 PDT 2015


Martin,
Anton,

Am 19.03.2015 um 15:01 schrieb Martin Gysel:
> Am 19.03.2015 um 14:14 schrieb Anton Lundin:
>> On 17 March, 2015 - Thomas Schrein (mailinglists) wrote:
.
.
.

>> I would be interested in such a device, even if they would be built as
>> one off jobs.
>>
>>
>> Only thing i would argue is really important is to make sure they fail
>> in a sane manner, and doesn't leak or dump my gas.
Doesn't matter, I have 2 bottles ;-)
No, joking aside: you are right, it has to be reliable! But I don't see 
a big deal with that, just copy proven concepts.

> It seems there's at least some interest in such a device but to get a
> retail price below 200 € one needs to produce/sell more then a couple...
> I also doubt a kickstarter project will help here :(
Making only a few parts is a funny hobby, making a lot parts is a funny 
business, both is worth to think about :-))

> Maybe the only option would be to design such a device in the public...
> I have some contacts to a pressure sensor company and a university,
> maybe that's a nice student project...
You need to know about the mechanical aspects+electronic+diving; don't 
think a students project is the right way, but may be I am wrong.
I discussed yesterday with my friend Marco, the mechanical chap in out 
team; he did not see too much problems building such a device, our 
problem is the lack of time, because we want to  concentrate on the 
progress developing odico.
But let's discuss about the features of such a logger; may be we have a 
time gap during the next month and we can build some parts, in 
particular because we planned to have a high pressure Sensor as CANbus node.

About the sensor: as a first idea we found this: 
http://www.amsys.info/sheets/amsys.en.me501_d.e.pdf
May you have an other sensor from the sensor company ?


>
>> Now this one is seriously OT but a idea i hand a couple of mates had as
>> a idea, a depth/time logger with a accelerometer/gyro and try to use that
>> as a mapping device to try to figure out how your movements under water
>> actually where.
>>
>> I talked with another mate who's in the defense industry and they have
>> such devices on there (semi)autonomous rovs, but they combine the
>> accelerometer/gyro with sonar and doppler radar against its surroundings
>> for more input to their odometry models.
>>
>>
>> That would be really cool =)
> Personally I doubt you get the needed accuracy by only using the
> accelerometer and gyro... but you could also couple it with some buoys
> which sends a ultrasonic beacon on which you can triangulate (like gps)
>
> /martin

That's an other story ...
By the way: you don't need a gyro, a 3-axis compass (+ accelerometer) is 
enough. I also saw some activities in the mil section .. and I agree, 
not so easy to get the needed accuracy.
If we have odico build up stable, we can modify/add some parts and go 
for a trial.

/Tom

> _______________________________________________
> subsurface mailing list
> subsurface at subsurface-divelog.org
> http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface



More information about the subsurface mailing list