Advice Needed V-Box blew up :(

The repeat setting is also found in Enigma 2 boxes, though I always assumed that they send several repetitions of the same command right at the start, in case there are a number of switches to get past and commands get 'lost' on the way ...
 
Captain Jack said:
The repeat setting is also found in Enigma 2 boxes, though I always assumed that they send several repetitions of the same command right at the start, in case there are a number of switches to get past and commands get 'lost' on the way ...
Click to expand...
You are correct ...
this is the intended purpose of repeat send ...
but it might be a way of fixing my problem ...
IF
such a thing were under user control and could be initiated by the F15 ...with several repeats and delays ...
Which sadly it cannot.
 
Vipersan said:
I rather suspect the dedicated micro for which I cannot find any info is running an internal clock which counts a fixed number of cycles approximating 60 seconds duration...
If parity of referenced command to stored command isn't achieved within this time frame the command is discarded ..
This being the case I see no fix ...other than to run at a higher motor voltage.
I am considering a rather odd and drastic bodge ...but no idea if it is even viable..
That is to run the micro at a lower clock speed..
Currently it uses a 3.58mhz ceramic 3 pin oscillator....presumably internally frequency divided by the software ..
I'm wondering if changing the osc to a lower frequency will allow the micro to still run ...but the clock cycles to reduce..
???VS
Click to expand...
Maybe the controller is similar to that used in the Motek V-Box? That can run at 3.58MHz.

Code: 
http://www.holtek.com/pdf/uc/48x50_1v201.pdf

(P.19 of the PDF for different oscillator values)
 
Llew said:
Maybe the controller is similar to that used in the Motek V-Box? That can run at 3.58MHz.

Code: 
http://www.holtek.com/pdf/uc/48x50_1v201.pdf

(P.19 of the PDF for different oscillator values)
Click to expand...
Interesting comparison Llew ..
The chip is indeed 28 pins ..not unlike the HT48R50A -28 SKDIP in the pdf..
And at first glance from the top the osc pins are possibly pins 21 and 22
Certainly worth closer investigation..
cheers
VS
 
Vipersan said:
Interesting comparison Llew ..
The chip is indeed 28 pins ..not unlike the HT48R50A -28 SKDIP in the pdf..
And at first glance from the top the osc pins are possibly pins 21 and 22
Certainly worth closer investigation..
cheers
VS
Click to expand...
Found some 2mhz 3 pin ceramic oscs on fleabay £3 for 5 minimum order ..so placed an order ..
Nothing to lose but £3 ...so worth the risk..


Also found an interesting side project during my investigations..
you might well be interested in building one Llew ..
Single pic and a 16 by 2 lcd display ..plus sundry bits ...and you too can own a diseqc decoder ..
Total build cost less than a tenner ..and since I know of no inexpensive meter that will do the job ..
..a nice tool to have if it works..
All credit to :-
Mike N0QBH
mikeberg@ringolake.com

rgds
VS
 

Attachments

Vipersan said:
Found some 2mhz 3 pin ceramic oscs on fleabay £3 for 5 minimum order ..so placed an order ..
Nothing to lose but £3 ...so worth the risk..


Also found an interesting side project during my investigations..
you might well be interested in building one Llew ..
Single pic and a 16 by 2 lcd display ..plus sundry bits ...and you too can own a diseqc decoder ..
Total build cost less than a tenner ..and since I know of no inexpensive meter that will do the job ..
..a nice tool to have if it works..
All credit to :-
Mike N0QBH
mikeberg@ringolake.com

rgds
VS
Click to expand...
That's a handy little gizmo VS. I've got a PIC programmer from days gone by, some time since I used it though. A little revision needed with that.

Thanks for that ;)
 
Llew said:
That's a handy little gizmo VS. I've got a PIC programmer from days gone by, some time since I used it though. A little revision needed with that.

Thanks for that ;)
Click to expand...
Chip and the display available on fleabay for about £1.50 per item ..including delivery from China.
Was yours an Elvis btw ..?
 
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Well ..at least I now know..
Fitted a 2mhz resonator in place of the 3.58 ..
Yes the Alpha display lights ...but the gbox pcb remains unresponsive as it do longer recognises remote commands or indeed commands issued by the F15 ..
So ..looks like the micros firmware is cycle critical ..
just swapping out the crystal is not a viable option..
Cost me £3 to find out ..but at least I no longer have the -what if - hanging over me.
cest la ie
 
Vipersan said:
Chip and the display available on fleabay for about £1.50 per item ..including delivery from China.
Was yours an Elvis btw ..?
Click to expand...
No, a Multi PIC Pro. Unfortunately, only takes a 24-pin PIC max, so wouldn't do for that project.
 
OK, thanks. Still rootling around in the junk box for any other programmers I might have. I'm sure I had one with the safe release key.
 
Llew said:
No, a Multi PIC Pro. Unfortunately, only takes a 24-pin PIC max, so wouldn't do for that project.
Click to expand...
Brain engaged. Of course My Multi PIC will take that chip.
 
Spent many hours reverse engineering the schematic for the Gbox ..
Can't guarantee it's all there yet ..
but so far it looks like this :-
Hope it proves useful as well as interesting.
rgds
VS
 

Attachments

  • Gbox schematic B.webp
    Gbox schematic B.webp
    81.5 KB · Views: 28
Nicely laid out VS, takes time to trace out a circuit - as I know with the SMPS's I've done.

Could put it up as a sticky in this section.

Just one query - I don't see where the supply comes from for the 7805 reg?
 
Llew said:
Nicely laid out VS, takes time to trace out a circuit - as I know with the SMPS's I've done.

Could put it up as a sticky in this section.

Just one query - I don't see where the supply comes from for the 7805 reg?
Click to expand...
Thanks Llew ..
I'd left that off but have now updated and replaced the schematic above..

also now added the voltage ratings for ZD1 and ZD2

I suspect the comparator sections B & C are responsible for processing and delivering the 22khz diseqc command to the micro on pin 15

parts A and/or D may generate a reset command for the micro ..

Pin 14 (micro) receives the reed switch pulses..
Pin 23 (micro) receives the 'activate' on when a receiver is also 'on'
pins 16 & 17 (micro) activate the relays to determine the dish direction of travel (AZ)
Pin 12 (micro) IR input from remote control handset
pin 26 (micro) CS clock set/sync for eeprom
pin 25 (micro) C clock eeprom
pin 24 (micro) D1 I2C sat position stored data eeprom

If you have any ideas please add them to the list..



btw ..
If anyone wants to try and identify the micro ..
The numbers on it are :- PP-01 0734
certainly don't mean anything to me but very similar to the HT48R-50A in the pdf above..
..but I suspect a custom mask version of the same ?
rgds
 
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Looks to be a good summary of the unit's working VS.

Never used a G- or V- box myself, preferring the positioner of the Echostar. Same basic principle applies though, using the Echostar's processor and eeprom's stored data to control the positioner.

Hope the acquired info you now have will help you to get your motors behaving themselves now ;)
 
Hey VS, how are you getting on with the Vbox mods you did? Anything to report? I still need to get around to fixing the blown up one.
 
not had much time recently ....and the effort put in taking care of mum whilst dad was in hospital has taken it's toll on my health.
thus..
My Vbox project took a back seat but is useable in its current form..
Maybe one day I'll get back to it..
rgds
 
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