Another general update

I have added a disclaimer page, see the pages section on the right to view.

Don’t worry folks, I haven’t left the z80 camp and joined the CNC/Fabber camp. I know there haven’t been any z80 updates in … uh a long time but I promise they will come. The building of the CNC machine is a long way off (few months to years) anyhow. I think as soon as I can get a mostly working design in my head, I’ll put the CNC Machine down and get to work on other things. Hopefully I can take some pictures of the LCD Tester and get back to work on it. I’ll try to keep the updates more regular.

Updated: LCD Tester Schematic

I cleaned up the schematic a little; it didn’t turn out as good as I had hoped it would, but it’s better than before. I have also included some labels to ease understanding. SInce it can be improved, I will almost certainly create a better schematic before releasing my page on the LCD Tester.

Disclamer: This is still only a rough schematic, so proceed at your own risk. I am in no way responsible if something bad happens as a result of building this circuit. Infact, there is a great probablility that some of the values are wrong.

Errata:

• R12 should be 5k ohms.
• SW10 is all jacked up. Basically SW10 should ground either pin 1 or 3 of the 7404. (I think)

LCD Tester Schematic

I have just completed a rough schematic for this tester. I hope to create a cleaner version at a latter time.

J1 is the group of header pins where the LCD module will connect with the tester. J2 isn’t really a header, it is just for proper interfacing with any LCD module. I plan on using two DIP14 IC sockets to implement J2. The photodiodes are supposed to be LED’s.

Enough blabbing, here’s the pic:

Lack of updates

Don’t worry folks, I haven’t given up on this project. I have put it on hold until I can get access to the camera again. Since I can’t document my progress, I saw no reason to continue work on it. I will have access to the camera after this Saturday.

In the mean time I have been working on Linux From Scratch and python programs.

LCD Update part 2

To Do:

• Design the case layout.
• Drill holes.
• Cut-out openings for LCD connector and personality chip.
• Install components(50% done).
• Wire components.
• Test

LCD Update

I have finished soldering all of the circuit boards for this tester. The design for the case is almost finalized, and work has begun on drilling the holes for switches and other components. I will try to get some pics of the circuits board and the case-before-wiring taken.

To Do:

• Finish soldering last circuit board, the module “personality” board
• Adding switch de-bounce circuit board to the enable pulse board, helping to reduce multiple enable signals.
• Design the case layout.
• Cut/drill holes and openings.
• Install components.
• Wire components.
• Test

LCD is progressing

I’ve breadboarded the debounce circuit. I get a nice, stable, debounced, enable pulse. (Here’s a nice page about switch bouncing and ways around the problem.) There is a strange, seemly random pulse that occurs on occasion when I apply power to the circuit, but it’s effects should be minimal.

I’ve also greatly expanded the description of my project in the z80 project page.

LCD Tester’s road map

Now that the design of Tester has been successfully tested, work can continue on building the case for it.

To Do:

• Finish soldering last circuit board, the module “personality” board (yes, all will be explained in due time. )
• Adding switch de-bounce circuit board to the enable pulse board, helping to reduce multiple enable signals.
• Design the case layout.
• Cut/drill holes and openings.
• Install components.
• Wire components.
• Test

Much better picture

It’s pretty much self-explanatory, I have put labels all over it. I’ve also covered up the parts of the breadboard that arn’t relevant to this project.

Success!!!!

I found this great website that helped me to getting this project working. http://www.epemag.wimborne.co.uk/resources.htm The first page of this website is very similar to what I’m doing. Thanks to Steve from Buffalo, NY for linking to this from his site on LCDs. http://home.iae.nl/users/pouweha/lcd/lcd_examp.shtml

As it turned out, the problem was the contrast of the screen. I had connected the pin directly to ground, thus giving me the most contrast. I thought this would be a good thing, but that made it far too dark to see. I think I was viewing the screen from a bad angle as well. After connecting the constrast to a potentiometer, and adjusting the constrast down, all worked out just fine.

As promissed, I have some pics. Unfortunately, the pics have bad resolution and they were taken in low light. The pic of the screen itself didn’t turn out at all. The first one is the breadboard of this project, and the second one are the switches I’m using to test it. I’ll post some better pics when I get them. (Yes, I’ll use a camera with a higher resolution than 100k pixels.)