Serial Port and big letters

supertyp2010 · 08-15-2012, 07:34 AM

Hello,

i'm new to the forum, and hope you can help me.
I'd like to use my kindle dx as a little scoreboard for table tennis. I have a wireless remote connected to an arduino, and all the processing is done by the arduino. I first wanted to use a LED Display, but the kindle would be a more flexible display-solution.
Now my questions:
1. (How) can i connect my arduino to the kindle using the serial port or USB? The arduino will send simple commands like "update score to 11:10" etc.
2. How can i print the big letters/numbers on the screen, is there a simple programming language which can use fonts etc. Or do i have to do the graphic stuff on my own (preparing each number as bitmap, etc.)?

regards
ST10

hawhill · 08-15-2012, 08:09 AM

I think the USB host mode of the Kindle is not explored enough to be a reliable choice. Also, implementing (virtual) USB on the Arduino is a resource-hog... So I would suggest to go via serial. Should not be too hard, given that the Arduino already works on TTL levels. Though the Arduino will probably use another voltage, so you will have to put in voltage conversion in between. For Arduino to Kindle, that could be just some resistors keeping the voltage down, but for the other direction the Kindle's TTL levels (1.8V mostly) will probably be too low and will need a driver. Maybe you can use some cheap spare AND/NAND/NOR chips for that. In combination with USB networking, this is also a very development-friendly solution since you keep shell access to your Kindle for testing.

As for the second task: Not that easy, but not too hard either. Shameless plug: The KindlePDFreader application is in fact a Lua scripting engine which - among other things - can be used for just painting some text and graphics in selectable font (just dump the high level Lua parts of that application and write some bits on your own). Might provide an easy start (because it's scriptable).

If you'd like to go more complex, I think the easiest starting point is Qt embedded (for which graphics output works almost out of the box - a small patch is needed - and input drivers are also floating around on the Web).

geekmaster · 08-15-2012, 09:22 AM

You could wire across the page turning buttons to display large scores printed in a custom ebook.

08-15-2012, 07:34 AM	#1
supertyp2010 Junior Member Posts: 1 Karma: 10 Join Date: Aug 2012 Device: kindle dx	Serial Port and big letters Hello, i'm new to the forum, and hope you can help me. I'd like to use my kindle dx as a little scoreboard for table tennis. I have a wireless remote connected to an arduino, and all the processing is done by the arduino. I first wanted to use a LED Display, but the kindle would be a more flexible display-solution. Now my questions: 1. (How) can i connect my arduino to the kindle using the serial port or USB? The arduino will send simple commands like "update score to 11:10" etc. 2. How can i print the big letters/numbers on the screen, is there a simple programming language which can use fonts etc. Or do i have to do the graphic stuff on my own (preparing each number as bitmap, etc.)? regards ST10

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08-15-2012, 08:09 AM	#2
hawhill Wizard Posts: 1,379 Karma: 2155307 Join Date: Nov 2010 Location: Goettingen, Germany Device: Kindle Paperwhite, Kobo Mini	I think the USB host mode of the Kindle is not explored enough to be a reliable choice. Also, implementing (virtual) USB on the Arduino is a resource-hog... So I would suggest to go via serial. Should not be too hard, given that the Arduino already works on TTL levels. Though the Arduino will probably use another voltage, so you will have to put in voltage conversion in between. For Arduino to Kindle, that could be just some resistors keeping the voltage down, but for the other direction the Kindle's TTL levels (1.8V mostly) will probably be too low and will need a driver. Maybe you can use some cheap spare AND/NAND/NOR chips for that. In combination with USB networking, this is also a very development-friendly solution since you keep shell access to your Kindle for testing. As for the second task: Not that easy, but not too hard either. Shameless plug: The KindlePDFreader application is in fact a Lua scripting engine which - among other things - can be used for just painting some text and graphics in selectable font (just dump the high level Lua parts of that application and write some bits on your own). Might provide an easy start (because it's scriptable). If you'd like to go more complex, I think the easiest starting point is Qt embedded (for which graphics output works almost out of the box - a small patch is needed - and input drivers are also floating around on the Web).

08-15-2012, 09:22 AM	#3
geekmaster Carpe diem, c'est la vie. Posts: 6,433 Karma: 10773668 Join Date: Nov 2011 Location: Multiverse 6627A Device: K1 to PW3	You could wire across the page turning buttons to display large scores printed in a custom ebook.

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