Forgot to copy the list... Didier KO4BB
Sent from my BlackBerry Wireless thingy while I do other things... -----Original Message----- From: shali...@gmail.com Date: Thu, 12 May 2011 13:07:13 To: David Bobbett<d.bobb...@tiscali.co.uk> Reply-To: shali...@gmail.com Subject: Re: [time-nuts] Tbolt LCD Monitor - No DAC reading I will check but I believe my 3 TBolts all return positive voltages for the DAC. The routine should handle negative voltages, but without having an actual data stream to check against, I can't tell for sure. If so, I may need someone who actually gets a negative voltage to send me the actual string returned from the TBolt. I will send you a piece of software that will capture it and save the data in binary to a file which you could then email back to me. That software is not written, and I am quite tied up at the moment, but I should be able to get to it in the next few days. If you run Linux, it probably would be easier with a shell script but I am running an old kernel here (2.2.6), so I am not sure whatever I come up with would work on your machine. If anyone has GPSMon displaying a negative DAC voltage, please let me know too. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -----Original Message----- From: David Bobbett <d.bobb...@tiscali.co.uk> Date: Thu, 12 May 2011 13:23:16 To: <shali...@gmail.com>; Discussion of precise time and frequency measurement<time-nuts@febo.com> Subject: Re: [time-nuts] Tbolt LCD Monitor - No DAC reading 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, shali...@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-boun...@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@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@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
