Products > Test Equipment

New handheld scope+DMM, Fnirsi 2C23T, 2ch, 10MHz/50MSps (Nov 2023)

<< < (3/11) > >>

dougie:

... yes I did ... however I don't think compensation will have an influence when measuring DC  ;)

lizard:
Got mine, echo most of the comments here re. accuracy etc.  Unfortunately I decided to upgrade the firmware to 2.0.2.  Bad move!  Bootloader made it to 99% and screen went blank.  I can get back in to the bootloader (reset pin, then hold menu while powering on), but not much else.  I downloaded the firmware from the FNIRSI site so I presume it's OK.  Contacted FNIRSI support who sent me a direct link, but no joy.  Waiting for a refund from Banggood.  Since I got to keep the non-functioning brick, I'll try diddling with the flash ROM when I get some free time.  Sigh.  At least it was cheap :)

dibu:
you could try flash the firmware directly via jtag/swd

the swd pins are routed to a unpopulated header near the reset button, the interface is not locked (at least not on my device), only flash is protected, so you will loose the original firmware together with the loader if you unlock it.
i also tried diddling with the firmware file, it looks like it is complete firmware (without the loader part?) contains also the unknown fpga bitstream.
Maybe you could loose something critical i'm not sure.

you will need to make a minimalist dummy loader to jump to the application reset and adjust the vtor

the main chip is at32 something i can look up the exact part number i don't remember exactly basically a stm32 clone (cortex m4)
i could look up more details if you want to try this, i'm not sure it will work, i haven't tried it, but if it is bricked anyway, what do you have to loose.

i'm still trying to figure out what the fpga and the multimeter chip is.
Also looking for others interested in reversing this.

lizard:
Thanks.  Was able to pull the documentation for the MCU.  There's also a serial flash (25Q64) adjacent to the MCU - bootloader maybe?  Should be easy to remove and take a look at the contents.

dibu:
the serial flash is just used to realize the filesystem used to store screen captures, also this is what you see when you connect via usb as usb mass storage. it uses elmchan fatfs. there is nothing interesting/hidden there

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod