Whoot Whoot! Solved it! I tried the link you provided with the 4.1.0.3 firmware flashed the firmware and after the upgrade was finished I instantly saw something displayed on my Matrix!!

So the solution was flashing the updated firmware, now I have the same result as in the video posted earlier but the with my Netduino!

Thanks a million for helping me out! I will now try to make some extra functionality to run more than one display for example.. or do you have more recent code?

YAYAYAYAY!! Awesome!

I have some more recent code that uses the custom bitbanger firmware to really blast the display (it so much faster its unbelievable).
I need to fix it up so that compilation is conditional i.e. you don't need special firmware, and I have optimised the font drawing and some other bits.
I'll take a look tonight and see if I can post it up.

-(e)

Well I'm going to give up for now I tried everything, I cut a connector from one of the cables and soldered the pins directly to it but I can't seem to get anything out of it.


I have 8 matrices and tried them all no luck with all of them. I really do not hope it is my netduino that is faulty or something.

I'm going to order a red 0832 matrix from sure to see if that one works for me..

One other thing I have thought of.. did you change anything in your firmware? maybe I have an older firmware or something? or isn't that possible, i'm such a newbee with Netduino

Hi,

Damn this is frustrating!

I run custom firmware for the bitbanger mod I made but this should not be a issue (the code attached is the original code I developed on stock firmware).

Do you by any chance have an Arduino? If so try the code from Miles Burton (linked in the first post) with your matrix and see if that works.

As a last option I reflashed with the original firmware to make sure there were no funnies there:
4.1.0.3 firmware

Then rebuilt the attached code and deployed it, it runs as expected. Try and do the firmware update, just in case. I have a watch on this topic so post back when you get the red matrix. I'd love to see this resolved!
Now to reflash back to custom...

-(e)

Thanks for your help, I think I have made those pin changes, I am using Syzmon's code at the moment, but am still struggling to get anything to appear. I have adjusted the display contrast as you suggested.

This stuff is hard to debug if you get it wrong

Can you give me the wiring between the shift register and the LCD pin for pin?
Also did you try and change BitOrder.LSBFirst to BitOrder.MSBFirst? Does that make a difference?

Step to the first SendCommand(0x03) and into that until the code has set the E pin high and sent the byte then check that the relevant pins on the output of the shift register are high / low.

Using the wiring I assume you are:

+--------- 0x80 d7
|+-------- 0x40 d6
||+------- 0x20 d5
|||+------ 0x10 d4
|||| +---- 0x08 enable
|||| |+--- 0x04 rw
|||| ||+-- 0x02 rs
|||| |||+- 0x01 backlight
7654 3210 

The byte should have been output as 0011 1011 to the Q7 to Q0 pin respectively:

Q7: low = d7
Q6: low = d6
Q5: high = d5
Q4: high = d4
Q3: high = E
Q2: low = RW
Q1: high = RS
Q0: high = BL

HTH
-(e)

I thought I would have another go at it, so I soldered all the connections to the LCD this time, and it worked fine thanks for your help

Hi I'm really glad to see you got it going
-(e)

Thanks alot for your help guys, I really appreciate it!

I am not sure how to go about measuring the pins, are you talking about physically checking their states or programmatically doing so? Sorry I am still very new to the hardware side of this!

My pins should be set up exactly to that in the diagram on Szymon's blog (as I have inspected my configuration several times!)

A few moments ago I did get some strange things appearing and being refreshed on the LCD screen. But have been unable to reproduce it.

Edit: The strange things appearing seems to be intermittent, it happened when I first turned it on this morning. Here is a picture...

Hi,

You may have:

• A bad ground, short etc.
• Misconfigured pin
• Inverted logic (bits in wrong order)

3. is affected by the MSB/LSB thing so should be easy to check.
2. you need to check your wiring again carefully
1. same as 2.

Edit: I have tried to puzzle out your wiring by looking at your breadboard picture, but there is not enough detail. If you could textually describe your wiring (what each pin of the shift register and LCD is connected to) that would help diagnose the issue.

HTH
-(e)

I am having trouble getting this to work I have used the code, and followed the wiring instructions here. I cant get the LCD to do anything other then turn on. Here is a picture of my current set up. Those LEDs just stay on/off as they are in the picture, and they should be flashing I think.

Any idea as to what I am doing wrong?

Thanks for your help

Firstly it looks like your contrast is at 100% (the completely white blocks would indicate this).
Try to just apply power (no signals lines) and turn the contrast down until the blocks almost disappear.

Secondly the Fritzing wiring diagram on Szymon's blog page is slightly incorrect w.r.t. the SPI port:

SHCP = PIN 13 (not 12)
STCP = PIN 10
DS = PIN 11

Thirdly which source are you using, Szymon's original or mine? If mine, have you configured the pin mappings correctly?

HTH
-(e)

Edit: one more thing you can try, once you have checked my points above is to change the MSB / LSB orientation of Szymon's code (if you are using his code). I had to change this to get my stuff working.

Hi,

First off with respect to my previous reply: tie-ing Vo to ground only works for certain displays. I have 2, one works and one just shows black blocks i.e. the contrast it too high.

Secondly I have built the shift register circuit but my wiring was totally different to Szymon's and so I need to alter the code to allow a different pin assignment. I have implemented a dynamic mapping system that should allow any wiring configuration.

Please see attached code.

The BaseShifterLiquidCrystalTransferProvider now makes use of a ShifterSetup class which handles the pin mapping.

Setup (which you can find in the test program) looks like this:

  	// 2. use shift register provider
  	ShifterSetup setup = new ShifterSetup();
  	setup.AssignBit( ShiftBit.Q0, LCDPin.BL );
  	setup.AssignBit( ShiftBit.Q1, LCDPin.DB7 );
  	setup.AssignBit( ShiftBit.Q2, LCDPin.DB6 );
  	setup.AssignBit( ShiftBit.Q3, LCDPin.DB5 );
  	setup.AssignBit( ShiftBit.Q4, LCDPin.DB4 );
  	setup.AssignBit( ShiftBit.Q5, LCDPin.E );
  	setup.AssignBit( ShiftBit.Q6, LCDPin.RW );
  	setup.AssignBit( ShiftBit.Q7, LCDPin.RS );

  	var lcdProvider = new Shifter74Hc595LiquidCrystalTransferProvider( setup, SPI_Devices.SPI1, LED_Latch_Pin,
                                                         				Shifter74Hc595LiquidCrystalTransferProvider.
                                                           				BitOrder.MSBFirst );

Also in the test program I fixed the CreateCharTest() test method to clear the screen before writing the custom character, which seems to make it work properly on my display.


Thanks

Edit:

Here is a pic of my circuit:


-(e)

Hi,
I have finally published the library on CodePlex. You can grab it here http://microliquidcr...l.codeplex.com/
Basically the same code as previously published on my blog, just with few renames.

Please let me know if you have any suggestions on what can be improved.

Hi,

Thanks for the brilliant library
I just soldered up a pc1602f display in direct GPIO mode and it all works nicely.

As a tip for anyone else doing this, if you don't have a pot of the correct value, you can just tie Vo to ground for maximum contrast (this had me stumped for a bit, I thought the display was broken )

On Monday hopefully I will have my shift registers and I can try it with that.
-(e)

This is awesome Let us know how the locking code goes, and can you tell me what you used to do the video? It looks really good and would be a nice alternative to a blog post for me to try out sometime. Thanks -(e)

What sort of things will you try? I tried stock SPI, bit-banged SPI, carefully managing the SCE (i.e. latch) line relative to SCLK, carefully managing the RST line relative to SCE, carefully managing D/C relative to MOSI, all the various commands (such as clear screen, inverse video, etc.) but I could not get the display to blink.

Hi,

If you have an Arduino lying about, test the display out with that first (I have both the Arduino and NetDuino).
This has helped me out in the past in identifying what the issue is, or at least confirming that my assumptions on setup and wiring are correct.
This should also eliminate the possibility that the display is broken (or otherwise )

If you haven't been taken up on your offer I'd be interested to have a look
-(e)

Hi, Its awesome you got this going I might have to get one now that you've done all the hard work -(e)

Does anybody from those who downloaded the firmware and possibly tried it have any feedback? How should I interpret the silence, with regard to initial eager requests? Please let me know whether it works or not with your device, so I can fix possible problems and publish the code. Thanks in advance.

Hi,

I have been meaning to look at this but I only just found a 1-wire supplier. I should be able to get hold of some sensors next week and I'll give it a go.

Looks like fun!
-(e)