Aquaaddict said...
Hi, thanks but checked syncs again, both connected ok, and image pretty much dissapears if I disconnect either. Forgot to say am only using about 9" of ribbon cable I presume that is not to long?
Ants
Ants,
You are using the same ground for the digital as you are the touchscreen analog.
You will need to ground the touchscreen analog somewhere else. It causes noise on the digital line.
I had the same exact image with Mctrivia's breakout board when I built them.
There is one ground which must be separated from the rest. If it is not, it causes noise on the digital line. Don't send someone on a wild goose chase.
I'm not the only case of this happening, there was a another member here which had the same problem, until I told him how to fix it.
I found this problem when I tested the first board that were assembled, There is a ground for the touch screen portion of the board, which must not be connected with the remaining screen grounds. I didn't have an o-scope at the time, so I can't say why.
Rays advice to check for bridges or lose joints is good general advice. Even though we tested every board before shipping it is still possible for a bad joint(and is why there is a 30 day warranty on all items i sell).
Solder bridge is very unlikely do to the boards being tested in advance(unless you have been using this in outer-space then it is very likely as these boards are not rated for orbital travel).
You can check for loose joints with a tooth pick or dental pick if you have one. Gentally try to wiggle the pin if it moves apply heat to the pin to reflow.
The problem however is more likely grounding. the longer your leads the better grounding you will need. All ground pins are interconnected on the breakout however ideally the ground pins closest to each set of signal wires should be grounded close to the connection point for those signal wires on the main pcb. The more ground points used the better.
mctrivia said...
Rays advice to check for bridges or lose joints is good general advice. Even though we tested every board before shipping it is still possible for a bad joint(and is why there is a 30 day warranty on all items i sell).
Solder bridge is very unlikely do to the boards being tested in advance(unless you have been using this in outer-space then it is very likely as these boards are not rated for orbital travel).
You can check for loose joints with a tooth pick or dental pick if you have one. Gentally try to wiggle the pin if it moves apply heat to the pin to reflow.
The problem however is more likely grounding. the longer your leads the better grounding you will need. All ground pins are interconnected on the breakout however ideally the ground pins closest to each set of signal wires should be grounded close to the connection point for those signal wires on the main pcb. The more ground points used the better.
Yes, Ray and yourself are right.
Connection points should be checked. There is never anything wrong with double checking any connection point. The more thorough a person is about finding possible problems the better off he/she is.
But I do recognize the PSP paint demo picture. It is the image I had when the touchscreen ground was on the same ground pin (propeller module from Gadget Gangster) as the rest.
For some reason that ground is much more critical than the rest with respect to noise. I believe it creates a lot of noise, which causes the screen ground to fluctuate when they are connected together.
just got on a PC so I can watch the video. I agree looks just like the results reached with bad grounding. That would be the first thing i would recommend trying.
Actually, now that I think about it some more, I think what I want is a driver, just like the Parallax one, but with 8x8 tiles instead of 16x16... That way, I can better mix in graphics with the 8x16 font text...
Thanks for all the tips, cant find any bad links or bridges so far, so think the ground idea could def be a possibility.
When you say a seperate ground, please could you clarify what would be considered seperate? I have tried running additional ground connections to the ground points on the breakout board (I realised they were all joined together on the board so only ran one initially), but its not made any difference, how would I isolate them other than just connecting them around different points of the Proppler board grounds?
That is kinda a strange problem... I wonder if it's really Vdd bouncing around that's causing the problem... Does that board use a single Vdd wire for both backlight and lcd? If the extra ground wires don't work, maybe try adding an extra tantalum cap for Vdd on the board...
Have just discovered if I select white ink in the PSB Paint app then the screen then displays and functions perfectly (as long as the background is red green or white, but isnt black), as soon as I try to select any other colour ink then it corrupts and scrolls to varying amounts as per my previous video. Also the initial PSB calibration screen always displays perfectly.
Aquaaddict said...
Have just discovered if I select white ink in the PSB Paint app then the screen then displays and functions perfectly (as long as the background is red green or white, but isnt black), as soon as I try to select any other colour ink then it corrupts and scrolls to varying amounts as per my previous video. Also the initial PSB calibration screen always displays perfectly.
That is somewhat of a different problem than what I experienced. I could never select a different color because of the strange problem. I didn't play with it in that state.
What I did, was split all the grounds into what they were for. The screen digital grounds got grounded to a different place than the Touch screen gnd. I know they are all connected with a copper plane, but it made a difference. I'm not sure why it made a difference, but it did.
Tried tying the gnd near the touch screen connection back to the gnd at the PSU, and all others to the gnd at the board, added a cap to breakout board, and still no difference what so ever. Seems odd that it works 100% perfectly when selected the white ink on paint, but fails consistantly when choosing a different ink (even though the other colours are shown on the screen; its such a repeatable regular pattern, and the additional seperate gnds have made abo(expletive)ley no difference at all, that i am wondering if it is a ground issue or somthing else.
Aquaaddict said...
Tried tying the gnd near the touch screen connection back to the gnd at the PSU, and all others to the gnd at the board, added a cap to breakout board, and still no difference what so ever. Seems odd that it works 100% perfectly when selected the white ink on paint, but fails consistantly when choosing a different ink (even though the other colours are shown on the screen; its such a repeatable regular pattern, and the additional seperate gnds have made abo(expletive)ley no difference at all, that i am wondering if it is a ground issue or somthing else.
Ants
Ants,
I have an idea.....but it's a long shot.
When I was building some of the boards, the through hole plating on the breakout holes were not great.
I would continuity check all the ground to their respective spots. It that all checks good, I would check the connections of the color pins. This is not going to be easy for the screen connector pins are real small.
The only difference between white, and any other color.......white uses all the colors, and other colors use less. Have you gone through all the different selectable colors? We may need to write a program which cycles through the colors to see if there are any others which are stable (PSP paint doesn't cycle through all of them).
I'm wondering if this is a connection problem (order), I figure you connected all the pins in order of how the driver asks.
You say it works with white ink......what about the background color?
What about a white background with a different color pen?
I would go totally back through all the connections to insure they are where they are supposed to be. Ground all the VSS pins. Take the Touch screen VSS pin to a different location on your interface board.
That is a strange issue... I wierd issue like recently when developing the 6x10 font driver... Turned out the clock speed wasn't fast enough for the pixel rate and Waitvid does strange things when it runs out of data and another waitvid isn't ready.
This is a long shot too, but I wonder if there's something wrong with your crystal... Surefire way to test your crystal is to try to output NTSC video to a TV. I've seen cases where a bad crystal connection would make it almost, but not quite work...
Rayman said...
That is a strange issue... I wierd issue like recently when developing the 6x10 font driver... Turned out the clock speed wasn't fast enough for the pixel rate and Waitvid does strange things when it runs out of data and another waitvid isn't ready.
This is a long shot too, but I wonder if there's something wrong with your crystal... Surefire way to test your crystal is to try to output NTSC video to a TV. I've seen cases where a bad crystal connection would make it almost, but not quite work...
Ray,
My problem with that....I would figure it would do it all the time, even with white. I am guessing here.
But something is definitely making Ant's life unhappy.
@Ant, I know you probably don't have one, but if you have an o-scope that would help a bunch.
Continuity checked each ground wire back to the breakout board, also checked each colour and sync pins etc from the prop chip leg to the LCD connector on the breakout board; all ok.
All VSS pins are grounded to one place near prop VSS, VSS near TS is taken straight to PSU terminal.
Was using this Prop setup recently with NTSC output, and have used it with LCD and OneWire; all OK.
Tried Rays suggestion:
Rayman said...
Actually, try lowering the pixel rate in Paint and see what happens...
Look toward the bottom of "PSB_LcdDriver" for this line and change:
PixelClock long 8_000_000 '500_000+ read-only
to
PixelClock long 4_000_000 '500_000+ read-only
Ra
which created a visable flicker when the screen was corrupted, but didnt change the corruption at all.
With regards to colours (sorry 'colors' for most of you), the calibrate screen looks normal, the inital PSB screen is mildly corrupted as per my earlier picture. As soon as I tap the white ink square the screen looks 100% ok (dont actually touch or draw elsewhere on screen), with·the black draw area; when·I touch the draw area the screen corrupts again. This seems to be because the black background doesnt work, the only combinations that do work are having white ink on green, white, or red coloured draw area, with any of these combinations I can 'paint' and its all normal. I have no idea how I get green or red draw areas, they only come up after the screen corrupts and·I tap around right section of the screen the colours change; then when·I tap the white ink square it returns to normal but with a coloured draw area.
I have also tried a brand new prop chip, exact same problems.
Have moved all the connections to different pins on the prop, still exactly the same.
Have also put a scope on all the breakout board terminals, and can see no difference on any terminal between when it is working and when its corrupted.
Just wanted to say a big thank you; I really do appreciate the time and effort you have put in to come up with suggestions and explain the possible problems.
Aquaaddict said...
Continuity checked each ground wire back to the breakout board, also checked each colour and sync pins etc from the prop chip leg to the LCD connector on the breakout board; all ok.
All VSS pins are grounded to one place near prop VSS, VSS near TS is taken straight to PSU terminal.
Was using this Prop setup recently with NTSC output, and have used it with LCD and OneWire; all OK. the rest snipped to save space......
Let me look at Mctrivia's board again. I may come up with more ideas but it's going to take some thought.
I hate to ask, but I'm counting pins, and I do not see the SDA, and SCL for the breakout board. You may be using a different name than what I expect, but I still do not come up with enough.
Could you give me a list of each break out pin, and where it is connected?
Well, maybe it just won't work with 9" wires... Perhaps something is coupling to the sync signals...
One thing I'd try is putting 100-Ohm (or 1000-Ohm)·to ground resistors on the sync signals at the breakout board.· That should reduce the effects of any capacitive coupling to the sync signals...
I hate to ask, but I'm counting pins, and I do not see the SDA, and SCL for the breakout board. You may be using a different name than what I expect, but I still do not come up with enough.
Could you give me a list of each break out pin, and where it is connected?
· BackLightPin=11·· · DisplayOnPin=8 ··PixelClockPin=10 · DataEnablePin=9 · TouchIrqPin=27· 'This pin is really optional, but touchscreen sets this whenever screen is touched · NotUsedPin=26·· 'Need to define one pin that is not to be used for LCD (can still be used for anything else) · VgaPins=%000_111··
Rayman said...
Well, maybe it just won't work with 9" wires... Perhaps something is coupling to the sync signals...
One thing I'd try is putting 100-Ohm (or 1000-Ohm) to ground resistors on the sync signals at the breakout board. That should reduce the effects of any capacitive coupling to the sync signals...
Ray,
I used a hard drive cable and had no problems (it is a perfect match for the boards holes). I did modify one end of the cable for connection though. I would have said that, but my cable was 12 inches or longer (actually more like 18 inches).
Comments
Ants,
You are using the same ground for the digital as you are the touchscreen analog.
You will need to ground the touchscreen analog somewhere else. It causes noise on the digital line.
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
ry.david:· The 8x16 font code is slightly different...· I'll post it and the input file here.
The input file is the output of a·program called "xFont" for Palm Pilot development (you can still download it from the web).
xFont puts out a .pfn file that I just rename to .txt so I can edit it with notepad more easily...
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My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board now in. $21.99 has backlight driver and touch sensitive decoder.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
I had the same exact image with Mctrivia's breakout board when I built them.
There is one ground which must be separated from the rest. If it is not, it causes noise on the digital line. Don't send someone on a wild goose chase.
I'm not the only case of this happening, there was a another member here which had the same problem, until I told him how to fix it.
I found this problem when I tested the first board that were assembled, There is a ground for the touch screen portion of the board, which must not be connected with the remaining screen grounds. I didn't have an o-scope at the time, so I can't say why.
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
Post Edited (James Long) : 1/1/2010 8:12:24 PM GMT
Solder bridge is very unlikely do to the boards being tested in advance(unless you have been using this in outer-space then it is very likely as these boards are not rated for orbital travel).
You can check for loose joints with a tooth pick or dental pick if you have one. Gentally try to wiggle the pin if it moves apply heat to the pin to reflow.
The problem however is more likely grounding. the longer your leads the better grounding you will need. All ground pins are interconnected on the breakout however ideally the ground pins closest to each set of signal wires should be grounded close to the connection point for those signal wires on the main pcb. The more ground points used the better.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board now in. $21.99 has backlight driver and touch sensitive decoder.
Yes, Ray and yourself are right.
Connection points should be checked. There is never anything wrong with double checking any connection point. The more thorough a person is about finding possible problems the better off he/she is.
But I do recognize the PSP paint demo picture. It is the image I had when the touchscreen ground was on the same ground pin (propeller module from Gadget Gangster) as the rest.
For some reason that ground is much more critical than the rest with respect to noise. I believe it creates a lot of noise, which causes the screen ground to fluctuate when they are connected together.
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board now in. $21.99 has backlight driver and touch sensitive decoder.
It is the 4th-5th-6th post from the top
http://forums.parallax.com/showthread.php?p=848975
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
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My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
When you say a seperate ground, please could you clarify what would be considered seperate? I have tried running additional ground connections to the ground points on the breakout board (I realised they were all joined together on the board so only ran one initially), but its not made any difference, how would I isolate them other than just connecting them around different points of the Proppler board grounds?
Thanks,
Anthony
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My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
That is somewhat of a different problem than what I experienced. I could never select a different color because of the strange problem. I didn't play with it in that state.
What I did, was split all the grounds into what they were for. The screen digital grounds got grounded to a different place than the Touch screen gnd. I know they are all connected with a copper plane, but it made a difference. I'm not sure why it made a difference, but it did.
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
For long ribbon cable adding an extra cap in the 10uF or greater region to vdd would be a good idea.
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24 bit LCD Breakout Board now in. $21.99 has backlight driver and touch sensitive decoder.
Ants
Ants,
I have an idea.....but it's a long shot.
When I was building some of the boards, the through hole plating on the breakout holes were not great.
I would continuity check all the ground to their respective spots. It that all checks good, I would check the connections of the color pins. This is not going to be easy for the screen connector pins are real small.
The only difference between white, and any other color.......white uses all the colors, and other colors use less. Have you gone through all the different selectable colors? We may need to write a program which cycles through the colors to see if there are any others which are stable (PSP paint doesn't cycle through all of them).
I'm wondering if this is a connection problem (order), I figure you connected all the pins in order of how the driver asks.
You say it works with white ink......what about the background color?
What about a white background with a different color pen?
I would go totally back through all the connections to insure they are where they are supposed to be. Ground all the VSS pins. Take the Touch screen VSS pin to a different location on your interface board.
I am out of ideas........
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
This is a long shot too, but I wonder if there's something wrong with your crystal... Surefire way to test your crystal is to try to output NTSC video to a TV. I've seen cases where a bad crystal connection would make it almost, but not quite work...
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
Look toward the bottom of "PSB_LcdDriver" for this line and change:
Ray
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My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
Ray,
My problem with that....I would figure it would do it all the time, even with white. I am guessing here.
But something is definitely making Ant's life unhappy.
@Ant, I know you probably don't have one, but if you have an o-scope that would help a bunch.
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
Hmmmm, that is interesting.
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
All VSS pins are grounded to one place near prop VSS, VSS near TS is taken straight to PSU terminal.
Was using this Prop setup recently with NTSC output, and have used it with LCD and OneWire; all OK.
Tried Rays suggestion:
which created a visable flicker when the screen was corrupted, but didnt change the corruption at all.
With regards to colours (sorry 'colors' for most of you), the calibrate screen looks normal, the inital PSB screen is mildly corrupted as per my earlier picture. As soon as I tap the white ink square the screen looks 100% ok (dont actually touch or draw elsewhere on screen), with·the black draw area; when·I touch the draw area the screen corrupts again. This seems to be because the black background doesnt work, the only combinations that do work are having white ink on green, white, or red coloured draw area, with any of these combinations I can 'paint' and its all normal. I have no idea how I get green or red draw areas, they only come up after the screen corrupts and·I tap around right section of the screen the colours change; then when·I tap the white ink square it returns to normal but with a coloured draw area.
I have also tried a brand new prop chip, exact same problems.
Have moved all the connections to different pins on the prop, still exactly the same.
Have also put a scope on all the breakout board terminals, and can see no difference on any terminal between when it is working and when its corrupted.
Just wanted to say a big thank you; I really do appreciate the time and effort you have put in to come up with suggestions and explain the possible problems.
Ants
Let me look at Mctrivia's board again. I may come up with more ideas but it's going to take some thought.
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
I hate to ask, but I'm counting pins, and I do not see the SDA, and SCL for the breakout board. You may be using a different name than what I expect, but I still do not come up with enough.
Could you give me a list of each break out pin, and where it is connected?
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
One thing I'd try is putting 100-Ohm (or 1000-Ohm)·to ground resistors on the sync signals at the breakout board.· That should reduce the effects of any capacitive coupling to the sync signals...
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
My Prop Info&Apps: ·http://www.rayslogic.com/propeller/propeller.htm
p0·· Vsync
p1·· Hsync
p2·· B0-2-4-6
p3·· B1-3-5-7
p4·· G0-2-4-6
p5·· G1-3-5-7
p6·· R0-2-4-6
p7·· R1-3-5-7
p8·· DEN
p9·· DE
p10· PCLK
p11· BL
p27· IRQ (PI)
p28· SCL
p29· SDA
Neg· VSS
3.3v VDD
And are set in my code as:
· BackLightPin=11··
· DisplayOnPin=8
··PixelClockPin=10
· DataEnablePin=9
· TouchIrqPin=27· 'This pin is really optional, but touchscreen sets this whenever screen is touched
· NotUsedPin=26·· 'Need to define one pin that is not to be used for LCD (can still be used for anything else)
· VgaPins=%000_111··
Thanks,
Ants
You can see that my PCBs are a disaster (Have you seen them?), with only 2 GNDs connected, and still work properly.
If it works for me, why do not you?
The only problem I experienced is that I had an LED connected to the vertical sync (Pin 16).
Do you have something else plugged into your Propeller?
Ray,
I used a hard drive cable and had no problems (it is a perfect match for the boards holes). I did modify one end of the cable for connection though. I would have said that, but my cable was 12 inches or longer (actually more like 18 inches).
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!