CwazyWabbit Posted June 29, 2011 Share Posted June 29, 2011 Finally I have the correct mileage in my car Took the long way home and put 12.5 miles on it, everything behaved as normal and the miles clocked up as I expected. So all is good in that respect. Hopefully tomorrow morning the trip mileage will still be there, but I don't have any reason to believe it won't be. During testing it has remembered a distance. Spot on For those that have been following the thread they may wonder why the mileage is 157,789 and not 197,000 as we were setting earlier.... Quote Link to comment Share on other sites More sharing options...
western Posted June 29, 2011 Share Posted June 29, 2011 privided the permanent 12v feeds are in place, the trip reading will remain until you reset the trip meter by pushing the reset button once to get the trip on the screen & then hold it down for a few seconds until it reverts to 0.0 miles Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted June 29, 2011 Share Posted June 29, 2011 True! To clear that up, this particular speedo was intended for the 110 (which has done 197k odd), but in order to give the methodology a good test we have fitted it to my 90. And in the process we've changed the mileage to that of the 90, 157k as above. The other speedo, which currently reads about 77k, will be set to the 110's mileage of 197k odd when it's done, ready to go back in that when it goes back on the road. So there's no speedometer fiddling going on, not in a downward direction anyway Quote Link to comment Share on other sites More sharing options...
PaulMc Posted June 29, 2011 Share Posted June 29, 2011 So there's no speedometer fiddling going on, not in a downward direction anyway . Quote Link to comment Share on other sites More sharing options...
slihp Posted June 29, 2011 Share Posted June 29, 2011 Quote Link to comment Share on other sites More sharing options...
western Posted July 1, 2011 Share Posted July 1, 2011 For those that have been following the thread they may wonder why the mileage is 157,789 and not 197,000 as we were setting earlier.... another Td5/ROW KMH speedo here Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 1, 2011 Share Posted July 1, 2011 another Td5/ROW KMH speedo here They definitely seem to be coming out of the woodwork now, I suppose people saw that one go for £68 the other day. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 3, 2011 Share Posted July 3, 2011 Just a thought, on the MPH gauge the 100km/h mark is past vertical, but on the KPH gauge the 100km/h is at vertical. Also, the MPH gauge goes to 120MPH, but the KPH gauge goes to 200km/h (125MPH). Possibly then, the gauges are programmed to move the needle different amounts based on the number of pulses? You sir are indeed correct! This evening I had a play with a KPH speedo and there are indeed a few degrees difference between the 100KPH postition on an MPH speedo and a KPH speedo. So I popped it open and read the memory out of it to see if there were any differences .... There were, so I reprogrammed the KPH speedo using the file I had from the MPH speedo we played with the other week ..... Connected it back up to the frequency generator I've been using for testing (which was still set to indicate 100KPH) and low and behold the needle now overshot 100KPH by a few degrees! Now we just have to work out what to change, but we have proved the KPH speed and MPH speedo are the same beast just with a different face and memory contents ... Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 3, 2011 Share Posted July 3, 2011 If you change the 0x09F4 and 0xB3FF on the KPH speedo to 0x1004 and 0x5CFF instead of showing 100KPH it now indicates just over 60KPH .... could it actually be indicating MPH but using the KPH scale? Did a second test, using the MPH speedo set the frequency generator to make the MPH speedo show 120MPH, connected it to the modded KPH speedo and it shows 120KPH.... EDIT: Just tested trip meter and that too has changed to working in Miles, well it is perfectly in sync with the MPH one anyway. EDIT Again to add video Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 4100 is 1004 in hex. Exactly what is in word 08. Word 09 is similar. Maybe one value of pluse per mile for the odo and one for the dial? You were right with the 0x1004 value, this is used to configure the trip meter and mileage record. So as you surmised it is the number of pulses per unit. I have verified this with two speedos in parallel, set at 0x2008 it registers only half the mileage and set at 0x802 it registers twice the mileage. Unfortunately this works in conjunction with word 13, unless we get the value right for this word then the needle stops moving. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 Words 17,18 and 52 (0x03C0,0x0780 and 0xACFF on MPH flash) seem to control what face it believes it has, if I change them on the KPH to match the MPH speedo the needle now moves as if it were indicating KPH on the outside scale of the MPH speedo. Changing any word individually seems to stop the needle moving. THe final two words in memory seem to make no difference whatever they are set to. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 After a bit of experimenting with words 8 and 13 I now have a speedo that reads exactly double the miles with both the trip counter and the needle so it appears that the first byte of word 13 is a check sum of some description, the valid pairs we have so far are:- 0x1004--0x5CFF 0x09F4--0xB3FF 0x0802--0x46FF so if we can work out how to calculate the checksum we can then calibrate the speedo Quote Link to comment Share on other sites More sharing options...
MrKev Posted July 4, 2011 Share Posted July 4, 2011 So words 17, 18 and 52 control needle deflection, and words 8 & 13 seem to control input pulse count calibration.... Have you got any more value pairs, 'cos I can't spot a pattern just yet Kev Quote Link to comment Share on other sites More sharing options...
Quagmire Posted July 4, 2011 Share Posted July 4, 2011 Amazing work MrWabbit, keep it up! Quote Link to comment Share on other sites More sharing options...
western Posted July 4, 2011 Share Posted July 4, 2011 Amazing work MrWabbit, keep it up! seconded glad you know what your doing MrWabbit cos I is Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 So words 17, 18 and 52 control needle deflection, and words 8 & 13 seem to control input pulse count calibration.... Have you got any more value pairs, 'cos I can't spot a pattern just yet Kev I haven't yet, I'll brute force another couple this evening. I think I'll try a close grouping around one of our existing pairs. Quote Link to comment Share on other sites More sharing options...
MrKev Posted July 4, 2011 Share Posted July 4, 2011 I think I'll try a close grouping around one of our existing pairs. May I suggest 0x2008 would be a useful figure, as that would be half mileage, so we'll have a set of 0x0802, 0x1004 and 0x2008.... Kev Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 May I suggest 0x2008 would be a useful figure, as that would be half mileage, so we'll have a set of 0x0802, 0x1004 and 0x2008.... Kev I'll do that one first then Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 I tried from 0x00FF to 0xFFFF just changing the first byte and was unable to get it to work, it may be I missed a number out as it's easy to make a mistake by hand. I'll try it again when my bus pirate turns up as hopefully I'll be able to script it then to remove the human error side of things... Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 After a bit of experimenting with words 8 and 13 I now have a speedo that reads exactly double the miles with both the trip counter and the needle so it appears that the first byte of word 13 is a check sum of some description, the valid pairs we have so far are:- 0x1004--0x5CFF 0x09F4--0xB3FF 0x0802--0x46FF so if we can work out how to calculate the checksum we can then calibrate the speedo 0x105F--0x01FF 0x105E--0x02FF 0x1006--0x5AFF 0x1005--0x5BFF 0x1004--0x5CFF 0x1000--0x60FF 0x09F5--0xB4FF 0x09F4--0xB3FF 0x0847--0x01FF 0x0804--0x44FF 0x0803--0x45FF 0x0802--0x46FF 0x0801--0x47FF 0x0800--0x48FF Interesting, found a bundle more 'pairs' but what seems an obvious pattern doesn't carry on. I can't guess the match to any others at the start and end of the sequences. Quote Link to comment Share on other sites More sharing options...
Davedef90 Posted July 4, 2011 Share Posted July 4, 2011 Being a technophobe and having a dislike of all things that I don't understand, I went looking on the net for someone to change my speedo reading I found this site. Is this the same format as a TD5 speedo http://www.gomog.com/allmorgan/VDOCALIBRATION.html Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 4, 2011 Share Posted July 4, 2011 Being a technophobe and having a dislike of all things that I don't understand, I went looking on the net for someone to change my speedo reading I found this site. Is this the same format as a TD5 speedo http://www.gomog.com/allmorgan/VDOCALIBRATION.html Unfortunately not, the aftermarket VDO speedos have a menu system to allow them to be easily configured. The TD5 speedo needs dismantling and some soldering to reprogram the internal flash chip. We can set the mileage reading on a TD5 speedo to whatever you like without paying the likes of digidash £100 for the privilege We are currently working out how to recalibrate the speedometers to allow for different tyre sizes and we can already freely convert kph speedos to mph speedos and the other way round without changing dials. All these things can be done by reprogramming the flash chip Quote Link to comment Share on other sites More sharing options...
Ex Member Posted July 5, 2011 Share Posted July 5, 2011 Solution with no parts to buy.... http://flashoffroad.com/Accessories/Gauges/vdo/Speedometers.htm Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 5, 2011 Share Posted July 5, 2011 Solution with no parts to buy.... http://flashoffroad.com/Accessories/Gauges/vdo/Speedometers.htm A neat solution to clocking on by using the standard serial port. The altering of the pulse per mile though is only available on aftermarket programmable VDO speedos as far as I can tell Quote Link to comment Share on other sites More sharing options...
MrKev Posted July 5, 2011 Share Posted July 5, 2011 0x105F--0x01FF 0x105E--0x02FF 0x1006--0x5AFF 0x1005--0x5BFF 0x1004--0x5CFF 0x1000--0x60FF So are you saying for example that these pairs didn't work, or did you omit them for brevity? 0x1003--0x5DFF 0x1002--0x5EFF 0x1001--0x5FFF Similarly, the run between 0x0847--0x01FF and 0x0804--0x44FF Kev Quote Link to comment Share on other sites More sharing options...
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