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SX20 IS firmware dump, I need help!

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Offline whoever

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Re: SX20 IS firmware dump, I need help!
« Reply #50 on: 13 / September / 2009, 06:23:44 »
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I didn't bother to try the udumper, because of reports of not working on similar cameras. And I don't know if I can run diskboots, I only tried the firmware update method.
With new encoding of diskboot, it was reported to work on SX200, which is a new camera.
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Anyway, can you provide some info about adjusting the timing? I have no idea how it should be, and it is not very documented.
Get your code to send out an endless sequence 10101010... Its frequency should be half of one of the standard baud rates (115200, 57600, 38400, 19200, 9600, 7200, etc.) You should be able to use a few thousand baud, at least 4800 (I blinked at 19200 baud).

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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #51 on: 13 / September / 2009, 13:17:34 »
Here's the code I used. It's the led finder code with the code from RaduP added. I noticed that the camera does only turn off normally (ie does not crash) when the while loop is present in the code.

Ok, first, when you run this code you must look at every LED the camera has (run it once for every LED, and watch it very carefully, in dim light conditions. The LED if triggered will blink for maybe 100ms. Look at the LEDs on the other side of the camera too.
What happens is that this loop doesn't go all the way, writing that number at a certain address tells the camera to shut down (gracefully). So you need to try a higher start address range, after that shutdown address. The your LEDs that are after that address will stay lit.

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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #52 on: 13 / September / 2009, 13:21:33 »
With new encoding of diskboot, it was reported to work on SX200, which is a new camera.

Yes, but didn't work on the SD960. Besides, I think the LED blinking way is cooler :D

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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #53 on: 13 / September / 2009, 22:20:58 »
After trying to work my way with a photoresistor for the mic input and not getting anywhere fast, I realized that duh, I HAVE quite a few photodiodes :D I forgot I ordered a bunch last winter for an unrelated project. So I am testing them now with the soundcard method.


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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #54 on: 13 / September / 2009, 23:45:09 »
Ok, I need some help now.
I am sort of a n00b at oscilloscopes, so how do I find the right timing? I should set the scale to around 250 microseconds, then eye how the signal rises and falls?

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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #55 on: 14 / September / 2009, 00:20:03 »
Nvm, I was doing it all wrong. I am going to set the base for 1 second and send 1/0 until I get it right, and then divide the second by the baud rate and stuff...
However, I found this in the wiki, and either it is a mistake, or if not, the SX200 must have a VERY fast CPU:
Code: [Select]
// 9600 bits/sec
// 1 sec approximately = 20569199 Delay on sx200 using 2 nop
// 20569199 divided by 9600 = 2142 delay time

For me a second is more than 10 times less :/

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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #56 on: 15 / September / 2009, 04:33:43 »
I am having a hard time getting anything with this: http://chdk.wikia.com/wiki/File:UART_receiver.jpeg
Looking with the oscilloscope at the signal, it's nothing like the signal I get from the photodiode.
I'll try the soundcard way.

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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #57 on: 15 / September / 2009, 22:55:39 »
Ok, it seems that the sound card method should be working. I downloaded xoscope for linux, and the signal looks pretty clean, good difference between 0 and 1. Now I need to find a way to save the signal, preferably for Linux, because that's what my basement computer uses. The advantage of the basement is that I can leave it there undisturbed, with the room light off.


Re: SX20 IS firmware dump, I need help!
« Reply #58 on: 16 / September / 2009, 17:12:44 »
The worst thing I did with regards to uart blinking was not understanding that the receiver is better at IR then visible light.  So when I was using the power LED it was bad but with the AF it was great.  The AF being an IR AF.  The uart serial port config was difficult to control quality and I dropped the block size to 256 I think.  I then did checksums twice (like in the sample code) and tossed any blocks that were wrong.

Also, I noted that there are A LOT of IR sources in a standard computer room.  LOL  Such as your LCD monitor.
Harpo
« Last Edit: 16 / September / 2009, 17:14:28 by HarpoMa »
Canon Models - SD300, SD780, & SX210

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Offline RaduP

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Re: SX20 IS firmware dump, I need help!
« Reply #59 on: 16 / September / 2009, 17:25:21 »
Well, I didn't have a noisy signal, I basically had virtually no signal at all. The signal from the photodiode alone was great though. So I am trying to develop a new audio protocol, that is slow but reliable.

 

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