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"Ruben =?iso-8859-1?q?J=F6nsson=22?= | 7 Sep 21:09

[EE] Problem with virtual com port for bluetooth unit

Hi,

I have a problem with a bluetooth connecton for a GPS receiver, using a virtual 
COM port in a PC.

My setup is as follows:
LevelOne usb bluetooth adapter (have also tried adapter from MSI).
Globalsat BT338, bluetooth GPS receiver.
Standard windows bluetooth stack in XP, sp2 (have also tried Toshiba and Blue 
Soleil).
A virtual COM port provided by the BT stack (bthmodem.sys).

My problem is that as soon as I open the virtual com port for the GPS receiver 
in my program I get 100% CPU usage (even when there is no communication). The 
component I use to communicate with serial ports is an ActiveX component called 
Commx from Greenleaf and my program is written in unmanaged C++ with visual 
studio 6.

The problem seems to be that the commx component doesn't like the virtual com 
port. Hyperterminal and other terminal programs seems to work fine. When I 
study the problems more closely it actually seems that it is one of the three 
threads created by commx when a port is open that loads the CPU. I can also see 
the trace message "Bad result from GetOverlappedResult in status thread" 
continouously in the trace window when I run the program through the debugger. 
The status thread is the one that handles pin change on the status and 
handshaking pins I think. All this seems to indicate that it actually is CommX 
that is the problem here. Other virtual comports seems to work fine though (USB 
to serial converter for example). I have been in contact with Greenleaf about 
this but they are clueless.
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Peter Loron | 7 Sep 20:35

[EE] Metcal noise?

For those of you who use Metcal soldering stations...

I have a used MX-500. It works well (heats up quick, correct temp,  
etc), but does a couple of things I'm curious about:

1. When plugged in and NOT powered on, it makes a faint buzzing/hum  
noise...maybe 60Hz.
2. When powered on and heating the iron, the buzzing/hum is louder.
3. When powered on and heating, the back of the unit gets warm.

Normal behavior? Sign of impending doom?

Thanks.

-Pete
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Olin Lathrop | 7 Sep 14:21

Re: [PIC] RS232 serial example code for a PIC16F84A

Grant Brown wrote:
> As I have said in other reply's, I did not say that the 16F84A is the
> right processor, buts its one that I have and as such I can without
> spending any further dollars start to explore the MCU world.

Get a few free samples of the 16F88 or one of the more modern PICs that are
pin-compatible with the archair 16F84 and inlude a UART.  Experiment with
the basic PIC 16 architecture with the '84 until the samples arrive.  There
will be lots to learn to get the first LED to blink.  Just getting used to
MPASM/MPLIB/MPLINK and debugging in MPLAB is a necessary step that can be
done pretty much on any chip, including the dinosaurs you have.

By the time you're ready for dealing with the UART, you'll have the samples
with the hardware UART.

> I had a look at some "C" bit banged RS232 serial source code.

Forget about C for starters.  Do the LED blinking and the first UART code in
assembler.  Once you have a basic working knowledge of that, then you can
start playing with C.

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(978) 742-9014.  Gold level PIC consultants since 2000.
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Olin Lathrop | 7 Sep 14:13

Re: [PIC] RS232 serial example code for a PIC16F84A

David Meiklejohn wrote:
>> Its interesting given your comments that NSW TAFFE still uses the
>> 16F84A to teach MCU programming.
>
> State-run technical colleges aren't exactly dynamic.  It takes a long
> while to update course materials, invest in new hardware, ensure that
> all instructors are familiar with the new material, and to roll it out
> consistently (e.g. assessment) in colleges across the state.

I've also noticed that as a group, teachers seem to be rather reluctant to
learn new things.

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(978) 742-9014.  Gold level PIC consultants since 2000.
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Spehro Pefhany | 7 Sep 13:54

Re: [PIC] PIC32 new development

At 10:34 PM 9/6/2008, you wrote:
>It seems Microchip has done quite a few good things for PIC32.
>
>1. Release of V1.03 unlimited code size C32 compiler, reduce
>the full version to US$895.
>http://forum.microchip.com/tm.aspx?m=353415
>http://forum.microchip.com/tm.aspx?m=364155
>
>2. Planned development of Ethernet/CAN/USB PIC32
>3. Planned support of uCLinux and .Net Micro Edition
>http://forum.microchip.com/tm.aspx?m=361485
>
>Xiaofan

So what advantages do you see over one of the more mature ARM variants?

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff <at> interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

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Forrest W Christian | 7 Sep 11:50

[BUY] Custom cable manufacturer for small jumpers

I am using a product which uses a 1.0mm header as shown at:  
http://www.jst-mfg.com/product/pdf/eSH.pdf

The product actually comes with a short cable, but the cable is too 
short (2 inches) for my application.   Plus, it also requires a surface 
mount connector on the other end (no THT version of the header is 
available).  

I would like to find a company that can or will create me a short (3 or 
so inches) cable which goes from this connector to something a bit more 
useful - perhaps a 10 pin dual row header or similar.   This will be an 
ongoing order - say 500 every 6 months or so.

My existing relationships with cable manufacturers are for more 
traditional "larger" molded cables, and they don't seem willing or able 
to make such a cable for me.  So I'm looking for another vendor.  
Unfortunately my google searches returns hundreds of hits, with very few 
real solutions - most don't seem to do this type of work.

Any ideas for such a cable manufacturer?

-forrest
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Grant Brown | 7 Sep 08:28

Re: [PIC] RS232 serial example code for a PIC16F84A

Hi Bob,

Thanks for that - It will give me something to start with.

Kind Regards
Grant Brown

Bob Blick wrote:
> Here are the examples that come with HiTech C. Obviously they will not
> work with C18. And they do not use a UART, they're bit-banged. One uses
> the TIMER0 interrupt, the other counts cycles.
>
> Cheers,
>
> Bob
>
>
> Grant Brown wrote:
>   
>> Hi List,
>>
>> Could any one please point me to a RS232 serial example in "C" for a 
>> PIC16F84A
>>
>> I have been googling heaps and seem to only find assembler code,
>>
>> However I need an example suitable for the MicroChip C18 compiler
>>
>>
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Xiaofan Chen | 7 Sep 04:31

[PIC] PIC32 new development

It seems Microchip has done quite a few good things for PIC32.

1. Release of V1.03 unlimited code size C32 compiler, reduce
the full version to US$895.
http://forum.microchip.com/tm.aspx?m=353415
http://forum.microchip.com/tm.aspx?m=364155

2. Planned development of Ethernet/CAN/USB PIC32
3. Planned support of uCLinux and .Net Micro Edition
http://forum.microchip.com/tm.aspx?m=361485

Xiaofan
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Olin Lathrop | 7 Sep 00:47

Re: [PIC] C mailing list

Matthew Miller wrote:
> Oh, I fully realize this. It's just that when I was reading, some
> regular posters were obnoxious about this issue.

You fully realize those posts are off topic, but yet are surprised when
people get upset about them!!?

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(978) 742-9014.  Gold level PIC consultants since 2000.
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Spehro Pefhany | 7 Sep 00:18

Re: [EE] Trickle charge current on NiMh

At 03:49 PM 9/6/2008, you wrote:
>I have a single-item application that requires battery backup. I am
>planning, for sake of simplicity, to use 4 cell 650mhA NiMh and keep them in
>trickle charge permanently. Simple limiter resistor will put the trickle
>charge at 20mA max (<1/30C) which is far below the 1/10C most people comment
>as acceptable for trickle charge. The NiMh are high quality Kan batteries.
>
>I saw different recommendations but in most cases manufacturers do not
>recommend trickle charging batteries permanently, although most admits that
>shouldn't damage the batteries. Therefore I perfectly understand this is not
>a recommended practice. Certainly a pulse trickle charge or a monitored
>dedicated charge is a more elegant solution.
>
>What I am looking for in the list is real-life experiences on permanent
>trickle charging being a real problem for NiMh. I am not thinking on this
>for large volume application which may require much better design (and time
>dedication), but in a single-item application I am ok assuming the NiMh may
>degrade to a point in which it has to be discarded in 2-3 years because of
>trickle charge.
>
>Thanks in advance

Trickle charging is *not* recommended as it will liberate hydrogen and
eventually cause enough of the electrolyte to disappear that the cell
will be useless. It *may* be acceptable at something like 1/50 or 1/40C,
but see the manufacturer's recommendations for the particular cells you
have in mind.

Can't you just turn the charge off after a period of time, like 30 hours,
without use?
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WH Tan | 6 Sep 23:24

[PIC]: Enhanced PIC16: A new PIC architecture from Microchip

Hi,

I heard of PIC16F1000, which is a newly announced (well not official
yet I guess, as I can't find any info on Microchip website)
architecture.  Those who went back from MASTERS 2008 has anything to
said about this new architecture? When it will be in mass production,
price etc etc ?

Thanks & best regards,

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Gmane