Finally, an affordable CD Transport: the Shigaclone story

So we should be able to use drivers to interface to other displays. Great. Is that an LCD display?

Well, things are not so simple.
As I previously said, this is a multiplexed LCD display. This have nothing to do with a static LCD display where you can, indeed, use drivers to interface with almost any other display.

In order to prolong LCD life and avoid electrolysis, an alternative stepped signal with multiple bias voltage level points is used to drive this type of LCD.
The selected segment will be in ON state al 0V but also on Vcc (3V or 5V depending on operation).
You can read more here Multiplexing and Bias of LCD Technology

Regards,
Tibi
 

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Yes, I was thinking it was only a multiplexed LCD and it would be possible to detect the low on the com1,2,3 lines as interrupts and then look at the s1-6 lines to determine which segment was on. Build a map and use a look-up table to translate to digits which could then be used to drive any display system. Lots of grunge work, but should be possible since the refresh rate of the display is low compared to the speed of processors.

The multiple level voltage to the Com and S lines complicates things.

I wonder if a com line could be buffered and rc filtered then run through a comparator to determine which way it was biased? Then only sample when it were biased under one condition.

This might result in unacceptable delay in decoding the display though.

It would certainly be easier to use a commercial product.
 
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Does the Shiga use negative voltage drive, or does it use 0-5V?

There is nothing in the LC78601E document to tell for sure since no waveforms are shown, but there are no charge pump caps so I suspect 0-5V. That rules out the lower two waveforms.

Pin 40 is "LCD drive bias 1/2 Vdd monitor. This implies possible symmetrical operation around Vdd/2.
 
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Does the Shiga use negative voltage drive, or does it use 0-5V?

There is nothing in the LC78601E document to tell for sure since no waveforms are shown, but there are no charge pump caps so I suspect 0-5V. That rules out the lower two waveforms.

Pin 40 is "LCD drive bias 1/2 Vdd monitor. This implies possible symmetrical operation around Vdd/2.

Shiga use 0-5V and works in three steps:
0V - ON
2.5V - OFF
5V - ON
You can chk with a scope.
The number of bias voltage level points is in direct relation with the number of digits.
In our case the display is in OFF state at 2.5V.

Regards,
Tibi
 
Today arrived the longer flex ribbon cables. The mechanism is replaced by a new one. So i connect the 6 wires to my motherboard with the new mechanism.
So i flip the switch and press the play button.... nothing..damn..:(
So i pull a new board from a spare jvc boombox and solder all required connections to my new board...finally it spins without any problems. :happy1:
The problem is in the motherboard, but where?
 
There is only one important point to note.

The laser as supplied new has a solder link in place to protect the it from static electricity damage.
You need to remove this small link with a soldering iron or sharp knife.
This is shown in the last picture of this listing.
It is to the left of the connector on the laser.

The problem is in the motherboard, but where?
You told us: The mechanism is replaced by a new one ... Why a new board from a spare jvc boombox?

Rudy
 

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Hi Rudy,

The problem was this:

Hi, I have a problem with my shigaclone.
If I try to play a cd, the player does not respond.
This is on the remote control and the control with the display.
If I close the switch, turns the cd neat and sees the numbers.
Only when I push the play button nothing happens. What can be the cause? Laser or print?

Regards,

Matthijs

So today i replaced the mechanism with a new mechanism to check if the problems come from the mechanism. But it still i have the same problems.So i put a new board to it and it works fine now.

And yes i removed the solder blob before playing.

Matthijs
 
Display Issues

A small update to this project.

I´m in contact with several LCD manufacturers in order to make a custom LCD who meet LC78601 specifications.

Regards,
Tibi

Tibi,

I really appreciate the lengths you are going to in order to make this project work. The display issues are a major pain and I wouldn't have known how to go forward. Thanks for your efforts.

If in the end, getting a display to work in the traditional way with the LC78601 is expensive or impossible, maybe we should consider what we really need out of this player. We are never going to get the fancy track title stuff that is possible on some machines, but I don't need that from this machine. For me, the most important thing is good sound quality and personal involvement of a DIY project. I'm not sure how others feel about this, but I don't care about identifying the track number, just about power on, play, and stop indication. The final approach might be to add a few LEDs as simple function indicators.

Any thoughts?
 
lehmanhill,

Thank you for your words !

We have redesigned a new transmissive LCD display with LED back-light.
The new LCD will have around 50mmx20mm display area.
A request for an offer was sent to 11 diferent display manufacturers.
At this time we have 4 offers.
The best offer so far is for a minimum quantity of 1000 pcs, but the unit price is quite high.
In the coming days we are waiting for few other offers.

On other hand, we are working on a atmel interface to a LED matrix as well. ;-)

In the mean time the prototype board is under production.
Stay tuned !

Regards,
Tibi
 
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Tibi,

I really appreciate the lengths you are going to in order to make this project work. The display issues are a major pain and I wouldn't have known how to go forward. Thanks for your efforts.

If in the end, getting a display to work in the traditional way with the LC78601 is expensive or impossible, maybe we should consider what we really need out of this player. We are never going to get the fancy track title stuff that is possible on some machines, but I don't need that from this machine. For me, the most important thing is good sound quality and personal involvement of a DIY project. I'm not sure how others feel about this, but I don't care about identifying the track number, just about power on, play, and stop indication. The final approach might be to add a few LEDs as simple function indicators.

Any thoughts?

We might as well go for true audiophile minimalism: just a power indicator. You can hear the rest anyway :D

(on a serious note, I wouldn't mind a display-less CD player for my personal use)
 
Big difference from Vinyl. At least you can look at the record and count what track you are on. A cd player without a display is not something I'd really want. If there was no other choice, sure, but I think a display is necessary. If I understand it, Tibi wants to make this a commercial venture. If that is the case, then a proper user interface is going to be a must.