| Electronics > Repair |
| Advantest R6581 VFD replacement |
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| IanJ:
--- Quote from: gamalot on November 24, 2024, 10:47:55 am ---I am also trying to do almost the same thing as dietert1 did, but it got delayed for some reason. I chose the STM32H750VBT6 because it is much cheaper than the STM32H730VBT6 if purchased from LCSC. I have only done a small part - displaying some pictures on the screen, which I think is a good start. Recognizing those characters should be easy, so presenting in different themes should be an option. I haven't looked at the manual yet, and don't know if the tR6581 can display customized content like some other instruments, if it can, special pattern character sequences can be recognized as some instructions to control the display to do anything it can do, such as changing the theme, adjusting the backlight brightness, running screensavers, etc. --- End quote --- Looks to be the same 4.58" LCD as I am playing with.....320x960 pixels. I am working with the LT7680 board from buydisplay.com which takes the heavy lifting away from the BluePill. Downside is that's an extra Pcb, but it's no big deal to integrate onto my mounting arrangement I have in mind......everything within the footprint of the LCD itself. I'm developing on Visual Studio 2022 with VisualGDB plugin. I first got MickleT's original source ported over to Visual Studio, compiling and tested, then added conversion of the R6581 bitmap data to strings. G1 to G47 and the annunciators. Am now working to integrate the new LCD drive.....hmmm, the LT7680 datasheet could be better! A great wee project to work on......makes a change from repairs here in the home workshop. Ian. |
| gamalot:
Thank you Mickle T. Thank you everyone! Maybe I should do something fun next. |
| IanJ:
--- Quote from: gamalot on November 26, 2024, 03:09:15 pm ---Thank you Mickle T. Thank you everyone! Maybe I should do something fun next. --- End quote --- Awesome gamalot!........I hope I am not too far behind you....:-) Ian. |
| IanJ:
Hi all, Here's my effort so far..... 4.58", 320x960 TFT LCD. STM32 Blue Pill (STM32F103C8T6) LT7680A-R TFT Graphics Controller. It's been quite a journey to get to where this is right now, but today I got text rendering working on the display.......over the moon and over the technical hurdle, should be easy from now! I decided to use the STM32 Blue Pill as I am experienced with them and they are easily integrated for somebody wanting to build up my version. However, out of the box and on their own they are NOT up to the task. Not enough I/O for one. I picked the LT7680A-R controller because of it's size, it's narrower than the LCD and will mean it's easy to mount on the back and it of course took the heavy lifting away from the Blue Pill, just simple SPI comms with the LT7680A-R is required. However, the way the LT7680A-r works is that you still need to communicate directly (via the pcb) to the LCD's ST7701S COG, albeit only once at startup to configure things. In total I needed 3 SPI ports, the R6581T gets one, the LT7680A-R and............oh, the Blue Pill only has 2 SPI ports! So, I bit banged a 3rd, the 3-wire interface to the ST7701S. It's only used once at boot so no worries. Actually, I nearly went with the STM32 Black Pill (I still might) as it has 3 SPI ports, but we'll see. I plan to design a Pcb thats the same dimensions as the LCD and mount everything on it. The green Pcb in the photo is just a temporary one used for dev. Software is developed in Visual Studio/Visual GDB, and through the STLINKV3 it's got pretty good debugging, I can live watch variables etc. By far the biggest problem was the LT7680A-R, the datasheet/manual and the supporting App notes are quite extensive. I had to sync the settings such as the back porch stuff and of course they are in different units and needed tweaked even after that. Also, having to set up the LCD PCLK, VSYNC, HSYNC settings...........having never driven a TFT direct before it was quite a learning experience. The LCD pic below is just the first font I picked, plan is to have the nicest, smoothest font I think. Thats all for now. Ian. |
| gamalot:
I tried to capture the dot pattern of all characters, but I only got 80 of them. There are a few characters that I have not been able to display on the screen, such as lowercase letters b, j, p, q, and left and right brackets. I attached the characters I found, each character takes 6 bytes, the first 5 are captured from the serial bus, and the last byte is the ascii value. I also tried to use different fonts to present them, maybe because of my lack of artistic cultivation, I am not satisfied with my work so far ... |
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