Reverse engineering a Schneider MVC - Page 1
Forum section: electronics / projects

author: Zoszko
author_rank: Contributor
timestamp: March 28, 2015, 03:17:41 pm
content: Hello Everyone,I have managed to get my hands on a couple boards from a Schneider "Full electric hifi system".The system has a so called MVC (Multivisual Control) on top of it. I would like to use that display if it's possible. I have already done some testing with a DMM so I have got some intel on this baby:http://zoszkoworks.com/projects/REV_SCHNEIDER.jpg(Huge 18MB image, it has everything I know so far.)I am aware that something like an Arduino would not be able drive the LCD directly, but maybe if we could tap into this driver board... Or simply just use anything like a Cyclone II is an option, but I have never done anything with FPGAs.Please if you can help me out drop a line. The unit has a separate board which has two 21 pin LCD displays (without backlighting) with an ST6041B6/DJ on-board I was unable to get a datasheet for that IC.http://zoszkoworks.com/projects/SCHNEIDER_LCD.jpg~Z

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 28, 2015, 04:23:12 pm
content: Someone here has the same display:http://www.mikrocontroller.net/topic/138130It seems that the datasheet posted, although for another display, enabled him to get it working.

author: Zoszko
author_rank: Contributor
timestamp: March 28, 2015, 05:09:52 pm
content: Thank you for replying! I don't speak German, so I have got no idea what they were talking about there.

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 28, 2015, 06:01:13 pm
content: You could try google translate, but I have no idea what the quality is, I don't speak Hungarianhttps://translate.google.nl/translate?&sl=de&tl=hu&u=http%3A%2F%2Fwww.mikrocontroller.net%2Ftopic%2F138130

author: Zoszko
author_rank: Contributor
timestamp: March 28, 2015, 07:01:44 pm
content: Quote from: PA0PBZ on March 28, 2015, 06:01:13 pmGrrr Google Translate the s***tiest thing ever. Well I have tried it and than gave up they were talking about something else as they did not had the datasheet. But as they have managed to get those 2 pages everyone made it work. So I have digged up the datasheets for these M5299As which turns out to be MSM5299A... and clocking looks the same so I'm good to go!? I have already ordered 2 types of inverters from Maxim so I will be able to get the negative supply voltage for the display.I'm still not sure how to get the backlight working.What about the other board do you have any ideas (ST6041B6/DJ)~Z

author: bktemp
author_rank: Super Contributor
timestamp: March 28, 2015, 08:58:40 pm
content: The display has no intergrated controller. You can drive the display using a dedicated controller (Epson has some controllers for STN LCDs) or a microcontroller with build in LCD controller (some ARM controllers or PIC24FJ128DA206 or any microcontroller with DMA and a bit of software).Quote from: Zoszko on March 28, 2015, 07:01:44 pmThose displays have an EL backlight. You need an EL inverter (typ. 100-150Vac, 100-500Hz)QuoteLooks like simple 7 segments + a few icons for time or frequency display. Probably not worth salvaging.

author: Yansi
author_rank: Super Contributor
timestamp: March 28, 2015, 09:13:39 pm
content: SED1330, RA8835P3N or similar might do it. Or wack there some PLD like the cheapass Altera EPM240T100C5N, plus a suitable SRAM (both will need one). Great exercise for VHDL coding.Doing that with MCU equipped with DMA is possible, but little tricky, if the MCU has a lot of traffic on its internal bus. I do not recommentd this solution.

author: Zoszko
author_rank: Contributor
timestamp: March 29, 2015, 10:17:30 am
content: Quote from: bktemp on March 28, 2015, 08:58:40 pmIf I am right there is an EL inverter on the controll board (top-right corner) as it's connected to the TDK EBX-552B which is on a separate board and than it goes directly to the backlight pins on the LCD. Do you think it's possible to get this one working for me or I should get a separate EL inverter and hope it will match the specs?The board has a SANYO LC3564PL (Static RAM, Dynamic RAM, Video RAM) + LC36256PL( CMOS RAM 32768 Words x 8 Bit static) + TMS27C512-15JL (PROM) + MSM6355 (LCD CONTROLLER LSI)So my guess is if I can power this up somehow I can use this Controller with my data coming in and possibly the EL inverter.The line and column requires negative voltage so this is still an open point. I will try my best and create a drawing of that top-right corner so maybe we can figure out what that does.QuoteWell more likely some sort of VU meter which directly gets he signal from the board with missing caps and the Stereo Amplifier.

author: Zoszko
author_rank: Contributor
timestamp: March 29, 2015, 10:21:57 am
content: Quote from: Yansi on March 28, 2015, 09:13:39 pmThe board has a SANYO LC3564PL (Static RAM, Dynamic RAM, Video RAM) + LC36256PL( CMOS RAM 32768 Words x 8 Bit static) + TMS27C512-15JL (PROM) + MSM6355 (LCD CONTROLLER LSI)So my guess is if I can power this up somehow I can use this Controller with my data coming in after some hacking. What do you think? As there is a ST90R30C6 (8K EPROM) which is possibly storing all the menus and stuff (or not) I might be able to get around this and tell the MSM6355 what to display directly from any other MCU.

author: bktemp
author_rank: Super Contributor
timestamp: March 29, 2015, 11:10:55 am
content: I could not find any details information about ST90R30C6, but it seems to be a microprocessor. One of the two SRAM chips is for the processor, the other for the LCD controller. The TMS27C512 EPROM contains the firmware.You need to remove or at least disable the processor. Then you can drive the data bus using your own microcontroller and use the LCD controller.

author: Zoszko
author_rank: Contributor
timestamp: March 29, 2015, 12:14:08 pm
content: Quote from: bktemp on March 29, 2015, 11:10:55 amhttp://pdf1.alldatasheet.co.kr/datasheet-pdf/view/23848/STMICROELECTRONICS/ST90R30.htmlThe pdf says E30-31 and T30-31 so it maybe a little error there. With some further researc I have found that the ST90R30XX is a "8/16-BIT MCU FAMILY WITH UP TO 64K ROM/OTP/EPROM AND UP TO 2K RAM" so thats our micro for sure and not an EPROM as I have said previously.Both of the RAMs are connected to the LCD controller:

author: amyk
author_rank: Super Contributor
timestamp: March 29, 2015, 03:10:13 pm
content: What exactly do you want to use the LCD for?It's not always necessary to use a dedicated controller - you can generate the signal required for controllerless LCDs, it's like generating any other video signal except even easier since you control the pixel clock. Some interesting demos of doing MCU direct to display here:http://www.linusakesson.net/scene/craft/http://www.linusakesson.net/scene/phasor/http://www.dos4ever.com/upong/upong.html

author: Zoszko
author_rank: Contributor
timestamp: March 29, 2015, 04:20:05 pm
content: Quote from: amyk on March 29, 2015, 03:10:13 pmWell nothing special I guess. Just some testing to see what can be done with such a display. Maybe displaying my Twitter feed and some other stuff like date, time, temperature. I'm a huge fan of car instruments so maybe I would create a "motec" like display for racing games.

author: Zoszko
author_rank: Contributor
timestamp: March 29, 2015, 09:45:12 pm
content: UPDATE:I had some other stuff to do this afternoon but as I have promised I have did bodgy drawing of the circuit I am curious about. I am not brawe enoug to put it in like an image so here's the link:http://zoszkoworks.com/projects/bodged_sch.jpgit's not a proper schematic I was just drawing the traces.BUT I have manged to get the negative regulator part sorted, so now I have just got to figure out how to give it some negative voltages to regulate. Also there is the EL inverter (I hope there is) which looks a little complicated for me. The LM317 there gives a 2,5V out (1k/1k) which directly goes into the tranformer. I have tried to give it 5V on it's Vin and taping onto the gound plane (yes it was connected with the regulators ground) it did 0.1A current but the screen was black (no backlight) maybe I was missing something.I really appreciate your help guys, I really want to get this working and I know I can do it with your help!~Z

author: Zoszko
author_rank: Contributor
timestamp: March 31, 2015, 09:32:32 pm
content: UPDATE #2:I have just ordered some DC/DC Converters with inverting outputs, these can go as low as -38V so regulating that down(up?) to -22V should not be a problem. These should be here by Friday, unit than I will try to figure out the EL inverter part and we are good to go.

author: Zoszko
author_rank: Contributor
timestamp: September 12, 2015, 11:20:45 pm
content: I know it's been a long time since I have updated this. But I have made some progress.Insted of building a proper negative supply circuit with some nice inverting boost converters from Linear I have just used a rectifier to get the voltage inverted. Using my 2ch bench psu I was able to provide the 5V for the logic and the -22 for the LCD line drivers.See the attachments for the result. I have got all the pixels working but there is no sign of logic as they are all on. I have tried to remove the 5V line and switch it back on, nothing changed. I have checked there is 5V on every IC, I have connected the lid switch as well. I might try just to run the display separately and clock some data into it directly. (I would appreciate some help with this part.)The backlight is still something I have got to get working. I have tried to trace this part of the PCB back to a schematic so it might help get things worked out. The blue text indicated the connectors between the different PCBs. (attachment #2)I would really like to finish hacking this now.