Reverse engineering ST62

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Greenbeast
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Joined: Sat Dec 26, 2020 5:44 pm

Reverse engineering ST62

Post by Greenbeast »

Unrelated to diy EV conversions but thought worth an ask here.
I have a 120 litre Ice cream batch pasteuriser, it is run by a STM ST62. I would dearly lovely to alter it's temperature range (currently 65-95C) so I wonder how naive it is to think about reading the code and modifying it accordingly?
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crasbe
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Re: Reverse engineering ST62

Post by crasbe »

As usual: It depends. There are several versions of the ST6 microcontroller, some are EPROM based (they should have a window then I guess?), some are OTP (one time programmable) and some even came factory programmed.
You'll only have a chance of altering the program on the first version, for the other versions you'd have to buy a new chip.

And that will only work if you can read and write the chip (it doesn't have an In System Programmer, so you'll have to have a dedicated programmer for it. Furthermore it has a Readout protection fuse. If that's set, you can't read out the program.). Then you'll have to disassemble the code (is there a disassembler?), make sense of it (if it was C code and compiled this might be harder, if it always was an assembler program this might be easier), make the changes and assemble it again (again, is there an assembler available?).

All in all it's a lot of work since it's a rather obscure microcontroller by todays standards.
Greenbeast
Posts: 115
Joined: Sat Dec 26, 2020 5:44 pm

Re: Reverse engineering ST62

Post by Greenbeast »

Thank you very much for that reply. I will abandon that plan and stick with more of a workaround for my issue
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