First line corruption

SpokePOV kit for bikes

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sparr
 
Posts: 196
Joined: Tue Nov 04, 2008 5:21 pm

First line corruption

Post by sparr »

About 25% of the time when I write to my SpokePOV and then read back or actually spin the wheel, I see random extra dots on the first line (that is, when the LEDs are in the vertical position). I cannot find any pattern to when this happens. When it does I either reload and send the dat, or just manually erase the extra dots and re-send.

Is this unusual? Any possible causes or solutions?

kayrock66
 
Posts: 150
Joined: Tue Oct 09, 2007 1:06 am

Re: First line corruption

Post by kayrock66 »

I've noticed the same thing. It works enough of the time for a bike wheel toy so this is probably why the bug is still there.

sparr
 
Posts: 196
Joined: Tue Nov 04, 2008 5:21 pm

Re: First line corruption

Post by sparr »

With the same image loaded into two of the banks the symptom is a lot easier to understand... The first (or last?) column is being pulled from the next bank. An off-by-one error in the offset/animation code, I will attempt to locate it.

sparr
 
Posts: 196
Joined: Tue Nov 04, 2008 5:21 pm

Re: First line corruption

Post by sparr »

And, to make it even more clear, with mirroring on one side shows a slice from the next bank, while the other side shows a slice from the previous bank.

sparr
 
Posts: 196
Joined: Tue Nov 04, 2008 5:21 pm

Re: First line corruption

Post by sparr »

To revive a dead thread, as I have revived my long dead from corrosion SpokePOV... This problem persists. I am again going to attempt to track it down.

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toddfun
 
Posts: 37
Joined: Sun Nov 16, 2008 5:24 am

Re: First line corruption

Post by toddfun »

I also see this problem and I normally reload all the banks from a file to fix this problem. I also have 3 boards on one wheel running off one sensor so the boards are wired together via the ground and signal pins of sensor points. I found that I have to have the other boards hard off (batteries out) in order to program the boards without errors. Hope that helps if you have three boards. If you don't then I too would like to know any solutions you come up with so I don't see this strange line pop up in the middle of my image again.

Rampart
 
Posts: 8
Joined: Mon Oct 08, 2007 9:50 am

Re: First line corruption

Post by Rampart »

I think you are talking about small bug in the firmware. Image on one side is shown with cooruption in one line.
Somewere in the forum there was:

Code: Select all

The problem is that on the back side the first line of pixels is wrong. I checked the firmware code (while looking into syncing several SpokePOVs) and found the bug:

Line 102 of main.c needs to be changed from
Code:

spieeprom_read_into_leds(anim_eeprom_offset + (1024UL-eepromaddr), BACK);


to
Code:

spieeprom_read_into_leds(anim_eeprom_offset + (1024UL-eepromaddr) - 4, BACK);


A classic one-off bug

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toddfun
 
Posts: 37
Joined: Sun Nov 16, 2008 5:24 am

Re: First line corruption

Post by toddfun »

@rampart, Cool I will try that out soon and post back my results. I never searched for a fix because I could just reload all the images and the problem corrected itself, but it was a pain not being able to load the images from the chip without corruption. Also, since I started removing the batteries from the other two interconnected boards when programming I stopped a ton of communication errors. I wouldn't say it was related to the line corruption issue but I haven't seen the line corruption since I started this new programming procedure either.

dt1000
 
Posts: 15
Joined: Fri Mar 04, 2011 5:08 pm

Re: First line corruption

Post by dt1000 »

Hmmm.
This is exactly the problem I am seeing on my SpokePOVs, except my image comes out corrupted every time.
How would I go about modifying the firmware and uploading it to the chip?
Thanks,
Dan

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