Comments on: Cricut Personal Dissection http://www.built-to-spec.com/blog/2010/02/27/cricut-personal-dissection/ Making Cool Stuff Mon, 30 Aug 2010 03:09:17 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Sherry http://www.built-to-spec.com/blog/2010/02/27/cricut-personal-dissection/comment-page-1/#comment-577 Sherry Sun, 15 Aug 2010 01:54:03 +0000 http://www.built-to-spec.com/blog/?p=180#comment-577 I bought a cricut expression at Goodwill for a song - but one end of the machine was off - piece is there to replace - and there is a gray cable that goes into the machine - but I can not figure out how to get into that area of the machine. I have taken the bottom off and pretty much of the side.... any ides on what the gray cable goes to and if I can get into the machine to connect - would love to see this machine work. I bought a cricut expression at Goodwill for a song – but one end of the machine was off – piece is there to replace – and there is a gray cable that goes into the machine – but I can not figure out how to get into that area of the machine. I have taken the bottom off and pretty much of the side…. any ides on what the gray cable goes to and if I can get into the machine to connect – would love to see this machine work.

]]> By: Craig http://www.built-to-spec.com/blog/2010/02/27/cricut-personal-dissection/comment-page-1/#comment-355 Craig Tue, 20 Apr 2010 03:23:29 +0000 http://www.built-to-spec.com/blog/?p=180#comment-355 Thanks for the info! I wish I had access to a good MSO or a least a scope with a bigger sample buffer; it might make figuring out the timing issues easier :). I'm currently busy moving my workshop to a new location, but I'll try and get some more info gathered and posted after I get settled in to my new location, which should be some time in the next two weeks. Thanks for the info! I wish I had access to a good MSO or a least a scope with a bigger sample buffer; it might make figuring out the timing issues easier :) . I’m currently busy moving my workshop to a new location, but I’ll try and get some more info gathered and posted after I get settled in to my new location, which should be some time in the next two weeks.

]]> By: Ned http://www.built-to-spec.com/blog/2010/02/27/cricut-personal-dissection/comment-page-1/#comment-338 Ned Sat, 17 Apr 2010 16:39:14 +0000 http://www.built-to-spec.com/blog/?p=180#comment-338 I've just opened up a Cricut Expressions machine for reverse engineering. Looks like the board is more or less the same as the smaller unit (despite having "Cricut Expressions" silkscreened on it). It also has the same 4Mbit SPI flash part (Atmel AT45DB041D) on it; mine is also named George. I'm using Macs here, which have the distinct advantage of having Dtrace available. So writes to (and reads from) the FTDI should be easily logged (with good timestamps). Also, I have a 16-channel mixed-signal oscilloscope which might help. My guess is that the over-the-wire communications is in terms of cubic Bezier splines (which are also the basis for TrueType fonts). These are easily scaled and rotated (once you accept the need for floating-point and matrix math). I've done a port of the Cairo library and also worked with a TrueType font driver, so I'm not unfamiliar with this stuff. And I also have hacked a lot of AVR code and done reverse engineering for a living. I’ve just opened up a Cricut Expressions machine for reverse engineering. Looks like the board is more or less the same as the smaller unit (despite having “Cricut Expressions” silkscreened on it). It also has the same 4Mbit SPI flash part (Atmel AT45DB041D) on it; mine is also named George. I’m using Macs here, which have the distinct advantage of having Dtrace available. So writes to (and reads from) the FTDI should be easily logged (with good timestamps). Also, I have a 16-channel mixed-signal oscilloscope which might help. My guess is that the over-the-wire communications is in terms of cubic Bezier splines (which are also the basis for TrueType fonts). These are easily scaled and rotated (once you accept the need for floating-point and matrix math). I’ve done a port of the Cairo library and also worked with a TrueType font driver, so I’m not unfamiliar with this stuff. And I also have hacked a lot of AVR code and done reverse engineering for a living.

]]> By: Andrew http://www.built-to-spec.com/blog/2010/02/27/cricut-personal-dissection/comment-page-1/#comment-269 Andrew Mon, 05 Apr 2010 08:01:52 +0000 http://www.built-to-spec.com/blog/?p=180#comment-269 Craig, If you're up to it, send me the code and I'll work on it as well. Thanks, Andrew Craig,

If you’re up to it, send me the code and I’ll work on it as well.

Thanks,
Andrew

]]> By: Ron http://www.built-to-spec.com/blog/2010/02/27/cricut-personal-dissection/comment-page-1/#comment-262 Ron Fri, 02 Apr 2010 05:09:33 +0000 http://www.built-to-spec.com/blog/?p=180#comment-262 I have a sneaking suspicion that the ATMega16 on the regular carts is responsible for matrix math, resizing or something like that. I have a sneaking suspicion that the ATMega16 on the regular carts is responsible for matrix math, resizing or something like that.

]]>