TTN (and others) Ipaq 5450 and low volume

cornz

Just blown £450 on a Ipaq 5450.

£15 on POIwarner and another £40 on TTN2 as an upgrade.

Connected, installed,yadda yadda but the volume level on the 5450 is shockingly low. Believe me, i do mean low.

My car is quiet quiet but i can barely hear the vocal commands and if i turn on the ICE then im shafted. Cant hear it at all.

Some digging reveals that this is a common problem on the 5450 and is due to a smaller speaker.

No sh*t Sherlock! My old 3760 blasted volume out and was easily audible with the ICE at comfortable listening level.

So, today, i trotted off into town, visited a few shops and made myself a small 2.5 watt mono amplifier. Got the bits from Maplin Electronics in sheffield.

Just finished building it, going to test properly over the next few days but its WAY better than without.

If anyone wants details, parts, piccies etc, i'll post em.

On a similar note, any electronics bods out there, how about this..

Most ICE systems have telephone mute. So, when a verbal command is given by TTN or whatever, a circuit picks up the output from the ipaq's earphone socket and then dumps the audio through the ICE using the phone mute.

Now, it needs to be a fast circuit, solid state cos i dont think relays are anycop for this due to back emf and what about opto-isolation?

Anybody care to contribute?

Cornz...
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DavidW

I considered the sort of circuit you talked about. You'd use the sort of circuit used as a VOX circuit by radio amateurs - an op-amp that acts as a comparator and drives a transistor low to pull the mute line low.

However, the lag in most stereos responding to the mute line going low is likely to be too long to catch the beginning of the voice command - I expect it would be on my OEM Vauxhall system, even with the radio on (if the radio is off, it's a substantial fraction of a second).

I can't see it being practical, really. There again, I have an iPAQ 3970 and often drive with the radio off anyway.

David

cornz

Agreed, however, with solid state i reckon its possible.

Problem with vox is it needs a noise, by the time the vox has picked it up and decided its a valid signal and not road noise , you’ve probably missed the start of the directions. So, instead of picking up noise through a mic, just detect the instantaneous voltage change on the audio line out socket. Its quicker than vox.

I stand to be corrected but i thought that as soon as the tel mute line was dropped low the radio switched off immediately, is this not the case?

Its such a pain that we have to go to such lengths after buying the 5450 which, as the flagship ipaq, shouldn’t need external mods like this......

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cornz

Just another thought! Maplins do a one chip voice recorder chip!

Could introduce a 1 second delay and play back the recored drections from its RAM.

Just a thought.......

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DavidW

The VOX circuit would be wired directly to the audio feed (which you'd have to mix down to mono) - so there'd be no problem with road noise. It should be possible to design the circuit to assert the mute line as soon as there is any audio.

It can still be described as a VOX circuit even if it's not taking its input from a microphone. All you're talking about is a comparator circuit driving a transistor.

Behaviour of radios to the phone mute line being asserted changes from radio to radio. I wouldn't be surprised if it failed to switch instantaneously - as it's designed as a mute for an in-car telephone installation, instantaneous muting of the audio source and switching to the auxiliary audio input would not be required. The result could be the beginning of your voice command being clipped off!

Voice recorder chip - impractical unless you can find one where you can both load and empty memory at once. A delay line circuit may do the job - but you really don't want any delay.

Whilst I feel some temptation to try to develop the circuit, I wonder if it's not more practical just to connect an external speaker. If I'm going to develop this, I'm going to have to re-do my phone installation again to allow me to experiment, and I've only just built the new, improved mark 2 version. I guess I could try some prototyping on the bench first, though.

I have my Nokia car kit fully wired to my Zafira's electronics using the VDA connector - it uses the power supply, mute and audio input, also the Zafira's microphone. I also derive a power supply for my Brodit mount from this wiring.

The circuitry would be of at least moderate complexity. You'd have to mix the iPAQ's stereo output to mono, and then tap off that to drive the VOX circuit.

You could probably just wire the collector of a NPN switching transistor to the mute input and connect the mute wire from the phone to the same point, open collector style.

You'd also need to mix the mono output you've mixed from the iPAQ to the mono output from the phone. You could probably do it with a single quad op-amp chip - unfortunately my experience of designing op-amp circuits is pretty limited.

The other pain is going to be dealing with the not necessarily common ground potentials - I think you'll have to put the three audio inputs (two channels from the iPAQ plus the phone audio) through isolating transformers.

Are there any interested electronic engineers reading?

David

cornz

Just tested the amplifier, works fantastically.

Sticks nicely to the back of the ram mount and gives brilliant loud clear speech.

Im a happy bunny...

Cornz..

PS, going to post some piccies of my VW passat install at some point, see what you think....

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zappy61

Have you considered the Arkon sf121 wireless audio adapter? I have one and it transmits the sound in FM from my pda to the FM radio in the car (or any FM reciever) so thaat the sound is crystal and you can play mp3 music if you wish. I got mine from totalPDA £25.
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Graham

cornz

Yeah, i looked into these a while ago, i decided that they were not for me...

As you'll see from the pics, my ipaq mount is a big

but it works fab.....
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naquada

Quote: Originally posted by cornz on 05 June 2003

Just blown £450 on a Ipaq 5450.

£15 on POIwarner and another £40 on TTN2 as an upgrade.

Connected, installed,yadda yadda but the volume level on the 5450 is shockingly low. Believe me, i do mean low.

<snip>

Just had a long conversation with HP about this issue as i'm about to go up to a new ipaq with wireless and BT, and as i use GPS (copilot) heavily this would be an issue for me as well..

they say (and I quote SAY here) that the speaker volume problem is present in 54xx units and that there are NO plans to remedy this.

however... 55xx (5555 was stated) have a new speaker and do not have this problem. in fact hp do not support their INS gps (copilot) system running on a 54xx system as they consider it dangerous to have to look at the screen, its only supported on 38xx/39xxx (both now end of life) and the 55xx series..

hope that helps...

russgunn

You could do what I'm about to do Cornz...I too have a decent ICE setup in the car. My Pioneer DEH-P9300R has an auxilary input reserved for 6 and 12 disc changers. However, because I only use the integral single disc slot this channel is currently free. Pioneer do an interface which will take a 3.5mm jack to RCA lead. Therefore I will have full voice command through my ICE system on the Aux input. Surely you could do the same if you have a fairly modern headunit? Trade off of course is switching back to CD or Tuner input for tunes! I'll have no lag though as the switch is instant, just no background music.

Talkingbollox

Have you tried the "loud" voice files that are an option on the cd upon installation of the voice files?

MikeB

I tried them on the 5450 and they still were not loud enough

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Mike Barrett

russgunn

Yeah, I tried the 'loud' ones as well and all I got was a slightly more distorted version, but certainly no louder!

andygrove

QUOTE:

they say (and I quote SAY here) that the speaker volume problem is present in 54xx units and that there are NO plans to remedy this.

however... 55xx (5555 was stated) have a new speaker and do not have this problem.

I can assure you that the 5550 model also has this problem. I upgraded from a 3970 recently (I test all pocketpcs at work so always get the latest) and it is so quiet that I stuggle to hear it over the road noise and kids in the back!! My first solution to this was the soundfeeder - what a waste of money! It would only stay on one frequency for about 5 -10 mintues before it started wandering, and now I have a Arkon cm55 mount (the powered Multimedia one). While the speaker is not great (MP3s sound terrible) it's perfectly good enough for the voice prompts.

Interestingly it seems to be identical to the Seido mount recently tested here

ANdy

Andy

russgunn

As a sort of side issue, does anyone know why my volume slider in settings always goes to zero once I've plugged a 3.5mm jack into the headphone output. I have the 5450 by the way. I have to keep going back into settings and putting it up to max before I start TTN2 or I won't hear the voice commands. It happens every time I plug it in and then power it off. The next time I start up the PDA it's down to zero again, but only after using the 3.5mm lead.

Strange?

Sorry for hijacking this post.

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