KEITHLEY 2001 Display Substitute

[Le_Bassiste]

this is my short story about a partially successful attempt to substitute an KEI2001 VFD display with an OLED of same size.
after i had acquired my KEITHLEY 2001, i quickly got the itch to do something about the very dim display. at that time, there was no affordable VFD available, and the two 7001 that i bought for salvaging a good display did not live up to my expectations. 

i stumbled across an OLED 256x64 WEX025664DGPP3N00000, which is mechanically very close to the original VFD. actually, it fits quite well into the slightly modified 7001 display frame, so i assume that it would fit into the 2001 frame as well, given that one is willing to hack the frame a little bit. externally, these changes wouldn't be visible, though. TiN had mentioned before that the comms beween main instrument processor and the display would probably not too difficult to decipher, so i went all in and bought
a display, an STM32L432 NUCLEO 32 board, installed an IAR ide, and started to put together some schematics and a layout for a display board.
of course, the project went totally over the top when i got the idea to integrate an I2C interface as well, because then i would replace this annoying passive LCD on my HP6626A as well.
two birds with one stone.
WCGW.
about half a year later, the VFDs for the 2001, formerly known to be unobtanium, became available through an eevblog forum member, who was so kind to sell me two of them.
so, that killed the the "2001" of the project, and i went on to create the display fonts for the LCD of the HP6626A, only to find out that i had screwed the pinout of the I2C connector big time, and that the complete display contraption would never ever fit in between the HP6626's front bezel and the chassis frame. thank you very much.
end of story is what you can see in below pictures. i still have two or three unpopulated p.c.b.s, and there is also a thing on shapeways to self-contain the display in some kind of mounting frame.

[Theboel]

my 2000 look for a new display, I do not know if 2000 and 2001 has same display.
I hope You have enough time to finish yours and share with us.

[TRN]

Hi,

Nice project; do you mind to share the schematics and STM software from this?

rgds

[Le_Bassiste]

can't locate the STM software for it atm, computer is hiding somewhere in the attics, but here's the schematics. 
note that the I2C part in the schematics contains errors and is not needed if you want to do a Keitley 200x style display, just omit all components in the green marked box.

[German_EE]

Nice work, you could make some Keithley owners very happy with this project, especially if it is adaptable to other instruments in the series.

[TRN]

Thanks for this, which is really appreciated

[TRN]

Do you by any chance also still have the PCB layout file?

Regards

[artag]

my 2000 look for a new display, I do not know if 2000 and 2001 has same display.
I hope You have enough time to finish yours and share with us.

The 2000 has a 14-segment display rather than dot-matrix. However, I would think there is a good possibility that the OLED would fit mechanically as the display bezel is similar. It may be that the display protocol is also similar.

The 2410 sourcemeter has a very similar display to the 2001 so this might work for that, too.

[coromonadalix]

I think a thread  about displays substitution(s)  by brand and models should be made here on EEV ?


Some led variants for old Fluke lcd models

THis one here

Hp Agilent 3458  led versions

Hp Agilent 34401a  oled version
 
Some Datron voltage calibrator  Vfd to led conversion ??

[TiN]

Let's do it. I want to replace VFD in 2182A nanovoltmeter (same display as k2000) to OLED to mimic k2001/2002 design.

Is it hard to find suitable size OLED and not cost hundreds $?.

[Le_Bassiste]

whoah, nice to see that my project finds some love after such a long time
this is the display that i used, was EUR 99.95 inc. VAT and shipping in 2016:
https://www.texim-europe.com/product/WEX025664DGPP3N00000-WSR
EDIT: found it on farnell's site
https://cpc.farnell.com/winstar/wex025664dgpp3n00000/oled-display-module-256x64-green/dp/SC15036


will be digging out my old computer and try to revive the project and then post my findings later.

this is a nice breakout board for testing those OLED displays:
https://www.digikey.de/products/de?keywords=ac164139-nd

the hirose connector that mates with above mentioned display:
https://www.digikey.de/product-detail/de/hirose-electric-co-ltd/FH12A-30S-0.5SH-55/HFK130CT-ND/1110398

the pictures show my initial prototyping setup. to solder the ceramic bypass caps closely to the hirose connector is in fact quite easy:
- first, mount the connector on the breakout board. this is the hard part, because the connector is quite heat sensitive, but also needs a lot of heat on the individual pins, as they make for the spring contacts and are "massive". you may want to have one or two spare connectors just for practicing 
- then, tape over the 0.6 mm and 0.7 mm pad rows with kapton.
- use some copper tape to form the ground plane on top of the kapton
- use an x-acto to cut out slits in the kapton where you want to solder the bypass caps. easy-peasy, no solder bridging.

[Le_Bassiste]

PCB gerber files.
again, note that the I2C portion was intended for use in a HP6626 and is not working properly. don't use the I2C feature, no need to populate it.

[jaromir]

What a lovely project  I always enjoy digging into those machines and uncovering how they work.
Perhaps I overlooked something, but is there known description of the keithley display board communication protocol? Did you decipher it on your own?

[coromonadalix]

@ Bassite  did you manage to find your stm code ??

For fitting the connector  and tests purposes  you have this pcb on Ebay  ??

https://www.ebay.com/itm/5pcs-FFC-FPC-30-Pin-1mm-0-5mm-to-DIP-Adapter-PCB-Board-Converter-Double-Side-F86/181526471978

[TiN]

Le_Bassiste
Thanks. I got myself 2182A, with it's ugly segment VFD. Want to pimp it out with 2001-style looking screen. Project for next year.

[Le_Bassiste]

@ Bassite  did you manage to find your stm code ??

For fitting the connector  and tests purposes  you have this pcb on Ebay  ??

https://www.ebay.com/itm/5pcs-FFC-FPC-30-Pin-1mm-0-5mm-to-DIP-Adapter-PCB-Board-Converter-Double-Side-F86/181526471978

from the looks, that connector from ebay should do the trick,too. mine is the microchip break-out pcb from digikey, i don't buy electronic components from ebay.
will look for code and stuff after xmas.

[msquared]

I don't know if this would be a good substitute. I found the following display which is already mounted on a board so there is no need for the fine pitch connector. If this display would work it looks like it might be fairly easy to interface the display with the micro which might make for a fairly easy display replacement.

https://www.buydisplay.com/green-5-5-inch-arduino-raspberry-pi-oled-display-module-256x64-spi

[coromonadalix]

Seems the same  minus the size as the one used in the hp Agilent 34401a  oled variant made by Qu1ck

Started in this thread
https://www.eevblog.com/forum/repair/hp-34401a-dmm-with-leaking-segments/

[TRN]

msquared,

thanks for Oled-link

Le_Bassiste,

The display from msquared link is manufactured in four different flavors:

1) 3-wire SPI
2) 4-wire SPI
3) 6800 8-Bit parallel
4) 8080 8-bit parallel

Since the 2001DMM uses 3 wire SPI to control the original VFD display, would it be feasible to use the 3-wire SPI Oled, and reprogram the MC68HC705C8 to control the display instead of using an additional STM Nuclio-32 board?

If this is not feasible for some reason, which version would one need to order to be controlled by the STM Nuclio-32 board; The 6800 8-Bit parallel , or the 8080 8-bit parallel version?

[Kleinstein]

It can be tricky to reprogram the CPU to work with a different display.  One would need a suitable compiler / assembler and get it in the original EPROM.

Adding a small µC in between is likely easier, as one can use a modern C compiler and IDE.
One is free to program the interface one likes most or that is easiest. I would prefer an SPI variant. The 4 pin version may be easier to synchronize.

[TiN]

Also MCU that is on original panel is mask programmed (OTP) so it's not reprogrammable.

[TRN]

TIN & Kleinstein,

Understood & thanks for the explanation

[Le_Bassiste]

Le_Bassiste,

The display from msquared link is manufactured in four different flavors:

1) 3-wire SPI
2) 4-wire SPI
3) 6800 8-Bit parallel
4) 8080 8-bit parallel

Since the 2001DMM uses 3 wire SPI to control the original VFD display, would it be feasible to use the 3-wire SPI Oled, and reprogram the MC68HC705C8 to control the display instead of using an additional STM Nuclio-32 board?

If this is not feasible for some reason, which version would one need to order to be controlled by the STM Nuclio-32 board; The 6800 8-Bit parallel , or the 8080 8-bit parallel version?

my Keithley 2001 communicates with the VFD controller via UART at 9600 baud.  so, i was using only the TX signal that comes from the Keithley 2001 digital board.
the controller on the OLED flex pcb is an SSD1322, and i was using  BS[1:0] =b10, which sets the controller to 8080 mode.
didn't think about using the the 6800 mode, though. here's the initialization of the SSD1322, just in case 

Code: [Select]

/* ************************************************************************OLED_Initialization
*/
void OLED_Init(void){                               
  HAL_Delay(5);                                                            //wait for VCI, VDDIO to stabilze
  OLED_Select;
  LL_GPIO_SetOutputPin (PIN_nRES);
  HAL_Delay(10);
  LL_GPIO_ResetOutputPin (PIN_nRES);
  HAL_Delay(10);
  LL_GPIO_SetOutputPin (PIN_nRES);                                         //OLED RESET done
  OLED_Write_C(SET_COMMAND_LOCK);
  OLED_Write_D(0x12);                                                      // set to UNLOCK
  OLED_Write_C (SET_FRONT_CLK_DIV);
  OLED_Write_D(0x92);
  OLED_Write_C (SET_MUX_RATIO);
  OLED_Write_D(OLED_YPIX-1);                                               //3F
  OLED_Write_C (SET_DISP_OFFSET);
  OLED_Write_D(0x00);
  OLED_Write_C (SET_DISP_START_LINE);
  OLED_Write_D(0x00);
  OLED_Write_C(SET_REMAP);
  OLED_Write_D(OLED_ORIENTATION);                                          // normal Ox11 A[7:0]
  OLED_Write_D(0x01);                                                      // normal 0x01 B[7:0]
  OLED_Write_C(SET_DISPLAY_ENHANCE);
  OLED_Write_D(0xA2);                                                      // use internal VSL
  OLED_Write_D(0xFD);                                                      // improve GS
  OLED_Write_C (SET_GPIO);
  OLED_Write_D(0x00);
  OLED_Write_C(SET_CONTRAST_CURR);
  OLED_Write_D(0x7F);
  OLED_Write_C(SET_MASTER_CURR_CONT);
  OLED_Write_D(0x0F);
  OLED_Write_C(SET_DEFAULT_GRAYSCALE);
  OLED_Write_C (SET_PHASE_LEN);
  OLED_Write_D(0xE2);
  OLED_Write_C(SET_ENHANCED_DRIV);
  OLED_Write_D(0x82);
  OLED_Write_D(0x20);
  OLED_Write_C (SET_PRECH_VOLT);
  OLED_Write_D(0x1F);
  OLED_Write_C(SET_2ND_PRECH_PER);
  OLED_Write_D(0x08);
  OLED_Write_C(SET_VCOMH_LEV);
  OLED_Write_D(0x07);
  OLED_Write_C(SET_DISP_MODE_NORMAL);
  OLED_Write_C(EXIT_PART_DISP);
  OLED_Write_C(SET_COLM_ADDRESS_RANGE);
  OLED_Write_D(0x00);            //from 0
  OLED_Write_D(OLED_NUMCOL); //to 63
  OLED_Write_C(SET_ROW_ADDRESS_RANGE);
  OLED_Write_D(0x00);            //from 0
  OLED_Write_D(OLED_NUMROW); //to 63
  OLED_Write_C(SET_DISP_SLEEP_OFF);                                        // switch display ON
  OLED_Write_D(SET_DISP_MODE_ON);
  OLED_Write_D(SET_DISP_MODE_NORMAL);
  OLED_UnSelect;
}



[TRN]

Le_Bassiste,

Thanks for your feedback regarding the SSD1322 controller mode, and initialization code
I can use a soldering iron, but unfortunately I am not familiar with c-programming, so the initialization code only will not get me much further with this project.
Do you mind sharing the complete code set with me?

regards

[MiDi]

Just stumbled on two similar 5.5" oled displays with SSD1322 and want to share that:

ER-OLED055 - Display
ER-OLEDM055 - Display on interface board
EA W256064-XGLG - Display yellow Edit: maybe it is same color as the others