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FNIRSI-1013D "100MHz" tablet oscilloscope

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1audio:
Help me understand the larger picture of how the scope operates- Essentially it has a dedicated stripped down Linux OS that boots and runs from an uSD card that is formatted Fat32 if I understand what has transpired. So if I can copy the "drive" image to a uSD card and swap it for the original I would be running your software.

If so it opens the opportunity to make more focused customized versions that can easily be deployed. There are limitations (2 ch 8 bits and the limits of the native ADC stuff) but within those limits one could make some interesting devices. Everything from a vibration or acoustic analyzer to some smart auto diagnostic stuff.

pcprogrammer:
Hi 1audio,

neither the original nor the new firmware uses linux. It is bare metal programming.

The way it works is that the F1C100s has a fixed startup program in ROM, the so called BROM. This program does a simple initialization of the processor and then reads sector 16 of a SD card if present of-course. When there is a correct boot header in the first 32 bytes of sector 16 the BROM will load the belonging program and executes it.

If no SD card or no boot header is found it tries the FLASH memory if present.

This is to our benefit, and what I use to load the new firmware without modifying the scope. By loading the new firmware package to sector 16 of the SD card in the scope it is forced to start the new firmware first.

Within the limitations of the original FPGA it is possible to make it what ever you like. The new firmware is not to complex and offers a display library to do simple graphics and text.

All that is needed to make your own stuff is a SD card boot loader and a main program. The boot loader is needed to enable the DRAM in the F1C100s, where the main program then is loaded and executed. The boot loader itself is loaded by the BROM in 32KB SRAM that is always enabled. To do display stuff this is not enough memory, hence the two stage startup.

To have my startup image displayed I use an extra step in the loading process.

* The boot loader that enables the DRAM and loads and executes the startup image program
* The startup image program that show the startup image, loads and executes the main scope program
* The main scope program.
To do this kind of process from the FLASH a different boot loader is needed. It has to address the FLASH instead of the SD card.

Hope this clears things up.

Cheers,
Peter

pcprogrammer:
Did not have a lot of time to work on the project the last week, but this morning I finished the mod on the scope to get JTAG connected.

It was not easy with older eyes and not as steady in the hand anymore as time has gone by rather quickly. One moment you are in your forties and then you are almost sixty. Did not do it like morris6, to whom I applaud for a job well done. I used a male flat cable connector. At first I tried to solder the flat cable wires directly, but that was no success. So I used lacquered copper wire to solder to the components and soldered the lacquered copper wires to the flat cable.

Used a bit of hot glue to fix the wires to the board.

And it works. Am able to reprogram the FPGA with the JTAG programmer and the Tang Dynasty IDE.

Gustavo:
Hi there everyone, neeed help with two things please.

1. Where in the states can I get some F1C100s, the ones foun in China take 6 weeks to arrive to Miami!

2. Attached is a picture of the processor schematic showing an USB interface IC. No such IC in my oscilloscope

Thanks in advance

pcprogrammer:
Hi Gustavo,

can't help you with the first thing.

About the second one, you forgot to attach the picture, but I think you misread the schematic. If you are referring to the schematic in the repository, of which I attached the bit with the "USB ic" this is actually the USB connector. Since it is a USB-C connector it has a lot of pins to allow the insertion of the plug in either orientation.

I was thinking about your scope and wonder what caused the problem in the first place. The original firmware has some test code in it that suggests factory testing before packaging. Within this test code there is a bit for testing the touch panel. It involves touching the four corners and the center. It will not continue to normal operation without completion of the tests.

Unless the tests are skipped all together, which can be done by writing a flag in the FLASH memory, it should not have left the factory if it was already defective.

So my advise is to also test the touch panel itself on defects by static measurements and / or using an Arduino, and check the PCB after the F1C100s has been removed on any shorts just to make sure it is only the processor that is defective.

Hope you get it fixed,
Peter

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