Can 236 transmit both serial and bluetooth simultaneously?

[floepie]

I'd like to be able to use this w/ a permanent PPC (nav and serial com) and mobile phone (for tracking via BT).

Is this possible? In theory, I'd tend to think so, unless the bluetooth radio shuts off when serial com is in use and vice versa....

Thanks....

[AllyCat]

Hi,

Yes the Holux 236 can transmit serial and BlueTooth at the same time, but only using the same baud rate and protocol (NMEA or SiRF). Note also that the actual signals on the "USB" connector are "CMOS", with different levels and inverted relative to normal RS232 (on COM ports).

Cheers, Alan.
_________________
Garmin GPS72H/76/60/45, Etrex H, Mapsource v6.5.
Acer N50,HP114,Loox N560,Dell x50,CF/SD cards to 4/32GB.
RoyalTek,Holux236,Navman B10 & Copilot(Globalsat) BT GPS,TomTom5/6.
Memory Map (v5.4.2 & v5.1.3 OS & Euro), GPS gate,OSGPSconverter.

[escape75]

Hi Alan,

I'm trying to interface the Holux 236 with
my PC's serial port - mainly to perform
a firmware update. but for now just to
read the data, and I'm having some issues.

I cam across your post - maybe you can help
I noticed you said the inputs were inverted ...

I connected the GPS Pin 3 to PC pin 2,
and Pin 1 to PC pin 5, but at 38400 8N1
I just see a bunch of garbage on screen.

Is there something that can be done easily?

Thank You!
Martin

[mikealder]

Have a read of This Post which has quite a level of detail, there is a specific cable available which contains the required converter in the lead - IIRC you could also use a Sony Playstation or PSP cable for the same job, I cannot find the specific cable right now but I have one in the "spares box" (somewhere) - I will try and dig it out and let you know where I got it from - Mike

[escape75]

Thanks for your reply.

I guess I should find that serial cable somewhere,
since I don't know how to invert those signals.

My firmware is GSW3.1.1_3.1.00.07-C23B1.03a

Is this the same one from official GR236V5.s file?

Thanks again,
martin

[AllyCat]

Hi Martin,

The Holux uses signal levels of about 0 and 3 volts, whereas RS232 uses levels of +/- 5 or even 10 volts. 0v from the Holux should correspond to +10v, +3v to -10v, but many COM ports will work with lower voltages, and may even accept 0v for the -10v level.

The "correct" conversion can be done with one of the many variations of the "MAX232" integrated circuit, but these require a 5volt power supply. You can sometimes steal some power from some of the other pins on a COM port, but it's rather hit-or-miss. Note that the Holux has its battery connected to one of the five pins on its connector, but I've never found a plug/cable with that pin accessible.

The correct interface cable costs just under £20 from Clove Technology
which is not totally unreasonable as it contains both USB and RS232 conversions. However, I will be interested if Mike can come up with a PSP cable. The only link I found was to connect a GPS (i.e. RS232 port) to a PSP.

So, there are various avenues to follow. Say which appeals best to you and I'll see if I can help further. Note that the latest firmware is 3.2.2 available here.

BTW, there was a minor error in my original post: The BT port can be set to almost any baud rate, but the wired port is always 38.4kbaud.

Cheers, Alan.
_________________
Garmin GPS72H/76/60/45, Etrex H, Mapsource v6.5.
Acer N50,HP114,Loox N560,Dell x50,CF/SD cards to 4/32GB.
RoyalTek,Holux236,Navman B10 & Copilot(Globalsat) BT GPS,TomTom5/6.
Memory Map (v5.4.2 & v5.1.3 OS & Euro), GPS gate,OSGPSconverter.

[mikealder]

It is indeed a PSP data cable similar to This One, I remember paying £1,99 for the cable plus postage, just don't connect the power connector of the three way lead and it worked fine - Mike

[escape75]

Thanks for your suggestions,
I'll try to find a similar cable somewhere closer to home (Canada)

So you're saying that PSP cable has the serial to USB
built-in, or is that a voltage correction to adapt to serial ?

Too bad they have no way of flashing over
bluetooth from a PocketPC directly ...

Martin

[AllyCat]

Hi Mike,

Are you sure that cable transfers data to/from the Holux?

I can see that the PSP remote control port is "RS232" (using CMOS levels) like the Holux, as shown here, but surely the USB 5-pin mini-type B connector is "genuine" USB2? I have no experience of the PSP, but don't see how a USB to "RS232" interface can be suitable for "downloading MP3 and video", and many advertisements for similar cables say they are suitable for PSP and cameras, etc. (which don't use an RS232 interface). They also seem a little too cheap and compact.

Martin,

Here is a project to make a similar interface. Also, it is said to be possible to flash the Holux using a Bluetooth dongle on your PC (instead of a cable), but you have to be very careful that SirfDemo doesn't unexpectedly change the baud rate (which it is very prone to do). And SirfDemoPPC is even more lethal: It "killed" my Holux (temporarily) within minutes, even though I (thought I) knew exactly what I was doing.

Cheers, Alan.
_________________
Garmin GPS72H/76/60/45, Etrex H, Mapsource v6.5.
Acer N50,HP114,Loox N560,Dell x50,CF/SD cards to 4/32GB.
RoyalTek,Holux236,Navman B10 & Copilot(Globalsat) BT GPS,TomTom5/6.
Memory Map (v5.4.2 & v5.1.3 OS & Euro), GPS gate,OSGPSconverter.

[mikealder]

Cheap it most certainly is, I have one of these leads and can confirm it works, I even told Holux UK about the cheap way of connecting the 236 via such a cable (when they were still operating) as this method was cheaper than they could purchase the cables they were selling for the same job - Mike

[AllyCat]

Hi Mike and Martin,

I can't say anything about the cable that Mike has, but I'm convinced that the vast majority of "PSP data cables" that Google finds are simple USB "Type A to mini-B" data cables. For anyone following this thread in more than 3 months time, here is a link that might still work!

The fastest that serial "RS232" interfaces normally use is about 112kbaud and at this speed even MP3 files would take about 10x longer than real time to transfer, and it would take more than 1 day to fill a 1GByte memory card !

Here is the best "evidence" that I've found so far, where the PSP interface is specified as:

Input/Output
= High Speed USB (USB2.0) (mini-B)
= Memory Stick PRO Duo(TM)
= Analog Video Out

Cheers, Alan.
_________________
Garmin GPS72H/76/60/45, Etrex H, Mapsource v6.5.
Acer N50,HP114,Loox N560,Dell x50,CF/SD cards to 4/32GB.
RoyalTek,Holux236,Navman B10 & Copilot(Globalsat) BT GPS,TomTom5/6.
Memory Map (v5.4.2 & v5.1.3 OS & Euro), GPS gate,OSGPSconverter.

[escape75]

Yep, I can confirm that a PSP cable that I found didn't work.

This one was just basically a USB to mini USB, + power plug,
but it looks like it didn't include any specialized circuits ...

Off to ebay to find a cheap Holux USB cable

Thanks!

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