[time-nuts] Tbolt LCD Monitor - No DAC reading

David Bobbett d.bobbett at tiscali.co.uk
Thu May 12 12:23:16 UTC 2011


Well just in case this helps, the DAC on my Tbolt is currently reading  
-0.056013V.  As before, it shows up OK on Tboltmon.exe and Lady Heather, 
reads all zeroes on the LCD monitor.

And just in case it is of any use, my Tbolt details from LH are:

App:  3.0     27 Jun 2002
GPS:  10.2   14 Nov 2001
Mfg:  10.00 24 Mar 2003
Ser:    0.80253721

I would have thought 5 minutes of testing would be more than adequate, I 
usually work on the principle that if there's no smoke it must be 
working fine  ;-)

David, G4IRQ



On 12/05/2011 11:46, shalimr9 at gmail.com wrote:
> The DAC voltage routine is the worst hack I have ever come up with (that was a close call....)
>
> The processor is an 8051 and the SDCC compiler I used does not have the floating point math library, so I had to decode the DAC voltage "by hand" and it is quite possible that the routine breaks down for some DAC values which I did not encounter here (I have 3 TBolts).
>
> I would be surprised if any bug could have survived the stringent 5 minutes of testing I subjected this project to but who knows... :)
>
> I will look at it. I also have a version of the code compiled with a different compiler (Keil) to try if someone wants to, but I doubt the problem is with the compiler.
>
> For those who have seen the wiki page for the GPSMon project, there is a new firmware version which can display local time (compensates for GPS offset, time zone and DST). However, the DAC routine is unchanged.
>
> Didier KO4BB
>
> ------Original Message------
> From: Mark Sims
> Sender: time-nuts-bounces at febo.com
> To: Time-Nuts
> ReplyTo: Time-Nuts
> Subject: [time-nuts] Tbolt LCD Monitor - No DAC reading
> Sent: May 12, 2011 2:56 AM
>
>
> I have a sneaking suspicion that I know what is going on... 
>
> Ages ago I sent the code for my first TSIP parser to someone (can't remember who...  was it Dieder?) who was going to use it in a microcontroller based tbolt monitor.  Fluke's monitor is just a lift of that design.  Well,  my code had a bug in the DAC message processor.  If I remember correctly it was something like reading the DAC value as a single precision number,  but the tbolt was sending a double precision number (or the other way around). 		 	   		
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> Sent from my BlackBerry Wireless thingy while I do other things...
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



More information about the time-nuts mailing list