SX20 IS firmware dump, I need help! - page 9 - General Discussion and Assistance - CHDK Forum  
« previous next »
Pages: 1 ... 4 5 6 7 8 [9] 10 11 12 13   Go Down

SX20 IS firmware dump, I need help!

  • 125 Replies
  • 56031 Views
*

Offline whoever

  • ****
  • 280
  • IXUS950
Re: SX20 IS firmware dump, I need help!
« Reply #80 on: 08 / October / 2009, 11:26:07 »
Advertisements
Quote from: neszt on 08 / October / 2009, 07:49:02
There are two delay defines in the blinker's main.c:
#define DELAY232 132
#define DELAYGAP 100
I don't know what delay should i modify? Only one, or either together?
You have to post (or link/refer to) the whole code. Otherwise, the #define's you've quoted are meaningless.
Logged
*

Offline yakabmarci

  • *
  • 16
  • sx20is
Re: SX20 IS firmware dump, I need help!
« Reply #81 on: 08 / October / 2009, 14:54:29 »
Quote from: neszt on 08 / October / 2009, 07:49:02
I got the first sx20 dump file, but it is definitely worng because of wrong delay values. I am not professional in this, so any help would be appreciated.

There are two delay defines in the blinker's main.c:

#define DELAY232 132
#define DELAYGAP 100

I don't know what delay should i modify? Only one, or either together?
How to determine the right value(s) with an oscilloscope?

Hello neszt,

I don't know what code are you using, but I think it is something like: http://chdk.wikia.com/wiki/Blinking_the_firmware_to_the_RS232_interface example code

in this case the DELAY232 is the bit timing, the duration of 1 bit
the DELAYGAP is the idle or wait time after one byte was transmitted

If you have an oscilloscope it is easy to calibrate these values.
for the DELAYGAP you could use a value as big as you want, it should not have theoretically a max value
(i would try 1000, after you got the correct timing, this value should be reduced)

DELAY232 should correspond to 1 bit timing. e.g. for 9600 baud, one bit time should be 1/9600 = 104.16us

If you have an oscilloscope, you could write a test program that transmits one const byte (0x55) and measure the width of one pulse. And calculate the correct value for DELAY232 from that.

If you don't have an oscilloscope, you could write a test program that tries a range of DELAY232 values and somehow encodes the current DELAY232 value and transmits to the pc through RS232, when you receive this correctly you've got the right value.

I hope this is useful,
Logged
*

Offline neszt

  • ***
  • 174
Re: SX20 IS firmware dump, I need help!
« Reply #82 on: 08 / October / 2009, 19:34:46 »
Hi!

I did some test with the program like you mentioned. I determined, that 100.000.000 delay took 63 seconds. This leads me about 164 delay to produce 9600 baud. The original delay value was 132, so I wrote a for cicle / for ( delay = 100; delay < 2000 ; delay++) /, and sent bytes (0x0a, 0x55, 0xaa, 0x50).

I saw precisely the for cicle from the blinking, and the result file corresponds to it, but non of the received bytes was 0x55. I have probably problems with the position between the camera and the receiver. It is too instabil, i just move a little bit, and i see changes in the received bytes (cat /dev/ttyS0 | hd)

Tomorrow i'll try to get an oscilloscope, but it is not my profession :)

Thank you for your help.
Logged
*

Offline yakabmarci

  • *
  • 16
  • sx20is
Re: SX20 IS firmware dump, I need help!
« Reply #83 on: 09 / October / 2009, 01:33:51 »
What kind of blinker hardware you have?
You can also check with the oscilloscope if the form of the signal is ok. i.e. correct signal levels(e.g. it is not inverted, '1' and '0' in the correct voltage range), correct timing, acceptable noise.
Logged
*

Offline RaduP

  • *****
  • 926
Re: SX20 IS firmware dump, I need help!
« Reply #84 on: 09 / October / 2009, 01:37:59 »
He is using the blinker I sent him, which is pretty good because that's what I used for the SD980 firmware.
Anyway, make sure to check the voltage as I told you in the e-mail. And do NOT use cat /dev/ttyS0, you MUST use the loader I sent you, because it sets the voltage and stuff.
Logged
*

Offline yakabmarci

  • *
  • 16
  • sx20is
Re: SX20 IS firmware dump, I need help!
« Reply #85 on: 09 / October / 2009, 02:59:00 »
Hello RaduP,

Some posts ago, you wrote that you got a clean, error free dump.
I misunderstood something? Wasn't this for the sx20  is?
Logged
*

Offline RaduP

  • *****
  • 926
Re: SX20 IS firmware dump, I need help!
« Reply #86 on: 09 / October / 2009, 03:22:34 »
No, it was for the SD980.
Logged
*

Offline neszt

  • ***
  • 174
Re: SX20 IS firmware dump, I need help!
« Reply #87 on: 09 / October / 2009, 06:44:54 »
Problem solved! Turns out, with oscilloscope. It was because of negated RS232 voltage, with my blinker hw. Now I changed the led on, off (0x44, 0x46), and I got the correct bytes!

Now i dump the fw with 9600 baud. I'll say it's ok, if i'll get identical files with several dump.

Afternoon we will see the results. (now I see english strings in the half-dumped fw :-) )
Logged
*

Offline neszt

  • ***
  • 174
Re: SX20 IS firmware dump, I need help!
« Reply #88 on: 09 / October / 2009, 08:35:34 »
Hi All!

Good news!

My first full low level dump available: http://neszt.hu/sx20_GM1.00F_v02.dump.zip

I run the dec.exe program on it, and it was crc ok, but I don't know what else could i do. Probably i am ready.

Thank you all for help!

Please let me know, if additional process needed.
Logged
*

Offline yakabmarci

  • *
  • 16
  • sx20is
Re: SX20 IS firmware dump, I need help!
« Reply #89 on: 09 / October / 2009, 08:50:44 »
it looks good, nice work!
Logged
Pages: 1 ... 4 5 6 7 8 [9] 10 11 12 13   Go Up
« previous next »
 

Related Topics