Timeline for Reverse Engineering RS232 protocol misterious last byte
Current License: CC BY-SA 4.0
14 events
| when toggle format | what | by | license | comment | |
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| Aug 14, 2020 at 21:07 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Apr 16, 2020 at 20:01 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Mar 17, 2020 at 19:24 | answer | added | Pep | timeline score: 1 | |
| Mar 17, 2020 at 11:55 | answer | added | Artelius | timeline score: 1 | |
| Mar 15, 2020 at 14:44 | comment | added | Pep | Thanks Robert, I thought the same, and tried to externally send the same signal that the PDA initially sends (90 + (18) zeros + 90 +90) with the last byte with a fixed value (90), and the main board does respond with the data It has configured, the problem is when updating which does not work, and I think that is where the last byte intervenes, it is quite curious I had never come across something like this | |
| Mar 15, 2020 at 14:04 | comment | added | Robert | There is a third option: The sent data may be just one byte too large and hence the last byte is just garbage from uninitialized memory that is ignored by the receiver. Send some data yourself and see if the last byte has really an effect. | |
| Mar 15, 2020 at 13:33 | history | edited | Pep | CC BY-SA 4.0 |
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| Mar 15, 2020 at 13:18 | answer | added | Igor Skochinsky♦ | timeline score: 1 | |
| Mar 15, 2020 at 13:10 | comment | added | Pep | Unfortunately it is not possible in this case since I do not have a reader for this integrated circuit and it is also very inaccessible on the PCB, hence the problem. I thought it could be a checksum or CRC but discard this possibility because it constantly changes with the same payload | |
| Mar 15, 2020 at 12:50 | comment | added | Igor Skochinsky♦ | Can you extract code from either part of the system to analyze it? | |
| Mar 14, 2020 at 18:29 | history | edited | Pep | CC BY-SA 4.0 |
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| Mar 14, 2020 at 18:23 | history | edited | Pep | CC BY-SA 4.0 |
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| Mar 14, 2020 at 16:55 | review | First posts | |||
| Mar 16, 2020 at 21:02 | |||||
| Mar 14, 2020 at 16:53 | history | asked | Pep | CC BY-SA 4.0 |