FNIRSI-1013D "100MHz" tablet oscilloscope

[pcprogrammer]

@Atlan,

I answer your questions here, as others might find it useful too.

How does FEL mode actually work?

FEL is something of Allwinner technology and build in to (some of the) the MCU's they make. When there is no boot program found on either the SD card or FLASH memory it starts this FEL code. This opens an USB connection with a host and allows for all kind of actions. See https://linux-sunxi.org/Sunxi-tools#sunxi-fel

does it have any advantage over uploading to an sd card?

It certainly does, because with the scope it becomes possible to load the compiled firmware directly to the memory and execute it. This way there is no wear of the SD card, and it allows for a bit faster testing of new development.

The default FEL mode does not allow loading to the DRAM because it does not enable it, but with the starting FEL via the bootloader the DRAM is enabled and therefore allows loading to it.

does it allow reset via PC?

No, you will have to power cycle the scope to reenter the FEL mode. You could add a menu option to the main menu though, that does this for you and with that avoid power cycling.

is a specially compiled firmware required?

No, the binary firmware as it rolls out of the .elf file can be uploaded and executed. For this you need the sunxi-fel tool found here. This one is build by me from the sources I found on the net and is intended for Linux only. Don't forget to set it executable.

I have used this during the development of both the 1013D and the 1014D firmwares. Very easy. Check the instructions in this file.

I load the binary to a non existing address 32 bytes (size of the BROM header) before the start of the memory to have it in the right location for the vectors. The original firmware binary does not need this.

[Atlan]

Why does it work when I have the number 220, but not if I use "variable"?

[pcprogrammer]

Why does it work when I have the number 220, but not if I use "variable"?

That is a very good question to which I have no answer.

Are you sure the variable is set to a correct value?

[Atlan]

Just changing the boot screen.
The time to select the option to start the firmware is approx. 2s, if you touch anywhere on the screen other than the buttons, the reaction time is extended to 9s. Added the remaining time counter.

[engineer.r152]

Good afternoon! In the latest version 0.025c, the screen was displayed with an offset, position correction via Loader LCD/TP Config does not help, it is in an offset position. This problem has been solved before!

[Atlan]

Also the boot screen is shifted?

[pcprogrammer]

When not mistaken the original boot loader loaded the configuration file for the display shift and the touch panel transform, so you probably have to add that again to the new one.

[Atlan]

v0.025d with botloader 0.02 it should be ok. After the first start it will be moved, but after the second it will be OK

[engineer.r152]

yes, the start screen is shifted, but the original firmware is not. I haven't tested the new version yet. Thanks!

[Felipe Lacerda]

v0.025d with botloader 0.02 it should be ok. After the first start it will be moved, but after the second it will be OK

Thanks a lot!
You made it very useful!

Is this difference between channels normal in AD comp?
Calibration seems ok to you?

[engineer.r152]

Now the main firmware and the alternative are displayed correctly, and the bootloader is still shifted.

[Atlan]

ADC comp is a bit high, but I saw that some people have it that way.

152. Try this, boot fw 0.03.
It initializes the display, prints error messages if they exist, loads data for image shift if they are correct, makes changes and displays the main boot menu.

[engineer.r152]

It's okay! Version.003 operates without bias in all modes.