Interfacing with PSP-290 GPS unit from Sony

[Psyberjock]

I've been thinking about the Initial Location thing. Perhaps there wouldn't be a second set of Lat and Long, because the PSP saves the state of the memory when it goes into sleep mode. Then the GPS unit only has to keep the current coordinates in their current place and when it realizes that it's powering up, it would change the flag of the initial location. Then by checking that flag it would know if those coordinates are current or old. It can also do a time check to figure out where the satellites should now be. Then if they're not where they should be, it can start finding them again.

This idea seems to fit with my current experience with the device. Any thoughts?

[deniska]

From what I see, it seems that the driver or the device have 3 initial position aquisition algorithms which can be passed to the device via sceUsbGpsSetInitDataLocation() method.
(since the method only accepts 0, 1 & 2 as parameters...

In any case, I am extremely dissapointed with the reception quailty of the device...
Even after the initial fix it tends to loose the fix frequently or tune on to "bad" combination of satellites, resulting in a high horizontal dilusion of presision (HDOP)...
I did a 10 minute test drive with a new version of MapThis! (with usbgps support). During this test the Sony unit lost the coordinates ~10 times, thrown the display location ~70 meters off the actual coordinates ~3 times (put the marker half a block away with incorrect bearing and HDOP >30)
Also, I could not get the initial fix inside the car, so I had to step out, walk away from nearby buildings and wait for ~ 3 minutes...

My holux gpslim236 unit would get a fix inside the car within ~50 seconds and have a stable fix with ~10m accuracy in the same area... :-(

So I am not sure if the sony unit is going to be useful for any serious navigation in urban areas...

I imagine that Maplus sowtware gets away with this bad gps reception quality by approximating the last known location to the nearest road (sticking to the road) which is impossible to implement in current version of MapThis...


Perhaps someone could disassemble the unit and find a way to atach an active anntenna (or any other way to increase the reception quality)


There is alway a chance that, somehow, I got a defective unit :-)

[Ursus]

From what I see, it seems that the driver or the device have 3 initial position aquisition algorithms which can be passed to the device via sceUsbGpsSetInitDataLocation() method.
(since the method only accepts 0, 1 & 2 as parameters...

In any case, I am extremely dissapointed with the reception quailty of the device...
Even after the initial fix it tends to loose the fix frequently or tune on to "bad" combination of satellites, resulting in a high horizontal dilusion of presision (HDOP)...
I did a 10 minute test drive with a new version of MapThis! (with usbgps support). During this test the Sony unit lost the coordinates ~10 times, thrown the display location ~70 meters off the actual coordinates ~3 times (put the marker half a block away with incorrect bearing and HDOP >30)
Also, I could not get the initial fix inside the car, so I had to step out, walk away from nearby buildings and wait for ~ 3 minutes...

My holux gpslim236 unit would get a fix inside the car within ~50 seconds and have a stable fix with ~10m accuracy in the same area... :-(

So I am not sure if the sony unit is going to be useful for any serious navigation in urban areas...

I imagine that Maplus sowtware gets away with this bad gps reception quality by approximating the last known location to the nearest road (sticking to the road) which is impossible to implement in current version of MapThis...


Perhaps someone could disassemble the unit and find a way to atach an active anntenna (or any other way to increase the reception quality)


There is alway a chance that, somehow, I got a defective unit :-)

Hi Deniska, thank you for putting so much effort into this although the result was not satisfactory. I was wondering if you are going to release this new version of MapThis so maybe (and let's hope) we can prove that your PSP-290 was defective Furthermore, different ppl around the globe can test out the same unit at different locations and see if same setbacks appear. Regardless what will happen, we sincerely thank you again.

Ursus

[bunky666]

Hi everyone

I'm a total noob with all this homebrew stuff, but bought a 290gps in hong kong just before Christmas. I'm back in London now, and last night finally upgraded my FW to 3.03 by dark alex. Yay!

Deniska - firstly, along with all others who've said it - well done for your sterling efforts. You're clearly a genius.

I tested your 'test' software last night, and was so happy to find it worked! Mrs Bunky wasn't too impressed with me keep nipping outside in the cold/wet evening, but it did see 8 sats almost straight away. It gave me a long/lat (which was acurate) pretty quickly - around 1 minute. I don't have any other gps gear so I have no idea if it's good or bad or indeed quick or slow, but I was happy with it anyway. Very keen to see it running with 'map this'.

I'm mac based, so I've no idea yet how to make maps, (ie you're clever app doesn't seem to like my machine!) - any ideas with that would be a huge help.

Keep up the good work!

[harbintennis]

I think the psp-290(*Worse searching satellite) that is not better than "DIY".

[dpathic2001]

Don't think your unit is defective I'm afraid...

I work in a company repairing UK Sat Nav units - We utillise a re-radiation transmiter/amp that enables internal GPS pickup for unit verification.
Even when the PSP-290 is sitting right next to the transmitter the same problems appear - around 3-5 SATs get fixed with decent SNRs only to disappear in around a minute. GPS state falls, when it reaches 3 again some Sats are re-established but seldom actuall fix again. All of this happens with the 290 unit not moving at all!

I so want this project and have donated recently but it is likely that the poor performance of the unit here is related to the unofficial software method of interfacing with the unit?

I've tried the Jap version of Mapplus but it just gets upset that I am in Fife, Scotland and not Osaka :-p

[bunky666]

I walked home tonight, over the Thames (fairly open area of London), and got a fix on 7 sats for around 10-15 mins without interuption (could see 10 most of the time). Acurate readings for my speed, baring, long and lat for all that time with no dropouts at all. Haven't had a chance to test it more than this at the moment though.

It's deffo not so good in built up areas - could see 4 or 5 sats walking in the street with offices around me, but no fix for 5 minutes. As soon as the landscape opened up, it fixed almost straight away. Once it's getting a fix, it seems to be holding it though.

Just tested again outside, (stationary) picked up 6-7 sats and a fix on 4, giving me an accurate lon/lat etc within 20 seconds of walking out into the street. Not a largely built up area I might add. Maybe it's me, but I think it seems pretty cool for a gps noobie such as myself.

[dcemuUser25]

Thanks for your great work, deniska.
I am anxiously waiting for the new version of MapThis that works with the psp attachment. :-)

Just a naive thought, would it be possible to port functions that have been used in Maplus to use that 'stick to the road' navigation in MapThis?

Cheers. Keep up the great work!!

[deniska]

I so want this project and have donated recently but it is likely that the poor performance of the unit here is related to the unofficial software method of interfacing with the unit?

I've tried the Jap version of Mapplus but it just gets upset that I am in Fife, Scotland and not Osaka :-p

You should be able to navigate to satellite status screen in Maplus.. (I believe it's the last option on the main menu)..please repeat your tests with maplus and let me know the results..
BTW, I am using the same driver version they bundle with their software.

[Bigwreck]

Hello, let me tell ya what I think.
I got a gpslim240 over Xmas, made a cable (with a headphone jack with the socom mic hack).
It works so well the I get a signal anywhere (except inside Wallmart) and It is so accurate for me that it even show what side of the rode im on lol. Plus its got bluetooth so when the psp is dead and long gone i still have an excelent gps .
I have never used the psp gps device but i could well imagine its prob crap compared to my 240.
great program deniska please keep compatability with the serial port, oh and the "stick to roads" thing sounds like a bad idea, what about moutian bikers and hikers etc..
Keep up the great work