Trying to use bicolor with 2 daisy chained (OUT_SIZE=64)

[flavio-fernandes]

Hi Gaurav,

This could be a mistake on my part, but when I tried to connect 2 displays,
I got some weird behavior: http://youtu.be/qz0MV_Dnq_Q

To get that, I changed OUT_SIZE to be 64; is that the expected way of doing it?
Not sure if this matters, but I'm using an Arduino Mega 2560.

Thanks,

-- flavio

[gauravmm]

Oh, you don't need to change the OUT_SIZE at all. Simply set the type of board in HT1632.h and see this example:

https://github.com/gauravmm/HT1632-for-Arduino/blob/master/Arduino/HT1632/examples/HT1632_Heart_Multiple_Bicolor/HT1632_Heart_Multiple_Bicolor.ino

[flavio-fernandes]

oh interesting.

will try that when I find more time to play.

3 follow up questions:

1. in my example, I reverted my changes on OUT-SIZE and still saw stuff
   happening on the second screen.
   do you experience the same? It looks to me that something on the screen
   1 is affecting the data on screen 2.

2. my intent was to make the 2 screens work as 1, so I could scroll a long
   text seamless across both of them. Do we
   lose that ability on this API? In my fork, I treat screen target as
   0->red 1->green and 2->spare and out-size determining
   how wide. With that, I kinda got away from needing to do channel.

3. did you use an Arduino Due to drive these displays? Last time I tried
   that -- a while ago -- I could not get it to work.

-- flavio

PS. please know there is no urgency in doing these; do it when you get free
play time!

On Mon, Sep 8, 2014 at 10:43 AM, Gaurav Manek [email protected]
wrote:

Closed #18 #18.

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#18 (comment)
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[gauravmm]

Oh, dear. I missed your message. I'll look into it and reply in a few days?

Gaurav

[flavio-fernandes]

no worries!!! pls take your time.

-- flavio

On Thu, Sep 25, 2014 at 12:57 PM, Gaurav Manek [email protected]
wrote:

Oh, dear. I missed your message. I'll look into it and reply in a few days?

Gaurav

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#18 (comment)
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[gauravmm]

Okay, each screen now has its own, independent buffer. You need to draw the string on each channel and each screen independently.

1. The screen alignment issue is likely due to a buffer overflow. Follow the example here: https://github.com/gauravmm/HT1632-for-Arduino/blob/master/Arduino/HT1632/examples/HT1632_Heart_Multiple_Bicolor/HT1632_Heart_Multiple_Bicolor.ino
   and you won't overflow the image buffer.

2. This lets you explicitly target screens and channels, so it is not seamless.

3. No, I have not. What frequency does the processor run at?

[hmy1]

I've been trying to get the library to work with multiple Sure Electronics 3216 RG displays. I think the problem is that the library assumes that each display has its own CS line, connected to separate outputs on the Arduino. That is how it works on the 3208 displays. On the 3216 display, there is a single CS line for all of the connected displays which must be pulsed at the proper time to select the correct display.

[trunet]

@hmy1 did you manage to get it work with multiple 3216 displays? I want to make my arduino due work with this display.

[flavio-fernandes]

@trunet I hit a some problems while using due. I think it is related to the timing used. Using my fork I can do multiple displays w/out trouble on Arduino 2560 or UNO. I also know that gauravmm's library was made to work with it too; but it is a little different on how it handle the screens.

[hmy1]

@trunet I ended up using the code at https://code.google.com/p/ht1632c/ which handles the CS for multiple 3216 displays correctly.

[trunet]

Thank you both.

@flavio-fernandes I have used this one and your fork. Both of them has problems with multiple displays. It's mirroring 0,0 on 48,0. Very strange.

@hmy1 I tried but it's incompatible with arduino due. I'll fork it and rewrite to access the pins directly on the due.

[flavio-fernandes]

@trunet np. You sure you used my fork? I recall having the issue you describe on gauravmm's at one point, but never on my fork. Either way, please keep us posted should you make progress on the due!