FNIRSI-1013D "100MHz" tablet oscilloscope

[tunk]

Hello, a new version of the 1013d oscilloscope came to me.

If you think it's a new version/revision of the PCB,
maybe you could post a high resolution photo of it?

[sigxcpu]

While trying to use @pcprogrammer's firmware did anyone encounter a magenta screen with nothing working?
The firmware backup works fine, SD card reformatting an flashing with the loader and files worked fine.
Recovery ("unflashing" the sector 16) works fine.

Both combinations of the firmware (with and without the splash screen) fail with a full magenta screen, frozen. They both display the splash for a very short time then everything is magenta.

I've attached a picture of the board. This is a Daniu ADS1013D acquired ~2 years ago from banggood, so I guess it is not a "new" board.

[pcprogrammer]

It seems to be the older type pcb but the FPGA does not have the Altera markings, not that it makes a big difference though.

I know others here have the scope with the BNC connectors sticking out like on your scope, but I don't know if they tried the new firmware.

Can you post the firmware you extracted with the firmware backup program, so I can compare it with the versions I have and see if there is a difference that could explain why the new firmware is not working?

The one without the splash screen is not tested, as described in the readme on the repository site.

Make sure you are using this file fnirsi_1013d.bin.  (https://github.com/pecostm32/FNIRSI_1013D_Firmware/blob/main/fnirsi_1013d_scope/dist/Debug/GNU_ARM-Linux/fnirsi_1013d.bin)

The additional configuration files are only needed when the display is shifted or the touch panel gives the wrong coordinates. (X or Y swapped or X and Y swapped)

[sigxcpu]

I've attached the TP file, too.

LE: It worked! I've used that specific fnirsi_1013d.bin you provided link for. I don't know what version of that file I was using before (the md5 sum was different). I was 100% sure I downloaded that one.
LE2: X is swapped, Y is fine (both standard and shifted). I tried tp_xy_swap sector but now X is fine and Y is swapped.

[pcprogrammer]

In the readme there is also an explanation about the configuration file. You just need to change one of the values and the touch panel will work fine.

See this file: https://github.com/pecostm32/FNIRSI_1013D_Firmware/blob/main/configuration_file.txt

Just change the last byte of the sequence to back to 0xFF and y will be fine to.

[salavat]

In the readme there is also an explanation about the configuration file.

Hello, I need some help)). Tried to upload your firmware. The most difficult part for me (mac user) was to format SD card properly, I tried various options - run gparted on ubuntu (did not work), using partition manager on windows (cannot recognise scope at all), etc, etc.

After playing around with formatting scope SD card on mac, I got 'SD card error" while booting the scope. FNIRSI logo appears at the beginning. I made a backup of the scope per your instructions on github page.

What should I do?)

[pcprogrammer]

I think others have successfully formatted the SD card with an apple mac.

Since your scope no longer boots, it can't be used as a PC coupled SD card reader/writer, so you have to open it up and take the SD card out and use a different SD card reader/writer to format the card.

You can also buy another SD card and stick it in the scope. Most likely it will already be formatted as needed. The scope will then boot the original firmware, provided you did not do things to modify the FLASH memory.

I only have experience with non virtual machine based Linux Mint in regards to playing with the scope. One important thing I found during development is the need for the un-mounting of the SD card partition(s) before using dd. Not doing so let to unpredicted results.

[salavat]

Thank you very much, that helped!

I am still want to use your firmware - what happens if I transfer firmware on just ordinary formatted card - will it work?
Do you know mac terminal command line parameters (diskutil) formatting sd card on scope as required? I searched for info, but could not find howto...

[pcprogrammer]

Most factory formatted SD cards have the free space needed before the partition to store the new firmware, so, I guess, yes you could use a new card.

Can't help you with the mac tools for formatting disks. Have never used modern mac's.

[salavat]

Most factory formatted SD cards have the free space needed before the partition to store the new firmware, so, I guess, yes you could use a new card.

Can't help you with the mac tools for formatting disks. Have never used modern mac's.

Thanks! One dumb question though)) how do I know that I am using custom firmware?

[pcprogrammer]

That is simple. Underneath the battery symbol you will see a version text and there is an additional top menu item.

See the screen shot here: https://www.eevblog.com/forum/testgear/fnirsi-1013d-100mhz-tablet-oscilloscope/msg4048552/#msg4048552

[cool2000]

Hello,

I added some code for the sd card emulation to the Scope_emulator based on qemu sources:
https://github.com/froloffw7/FNIRSI-1013D-1014D-Hack
And also add AllWinner f1c100s ARM CPU and FNIRSI-1013D hardware support to qemu:
https://github.com/froloffw7/qemu
Qemu emulation is running quite smooth similar to the real device. Some QEMU screenshots here:
https://github.com/froloffw7/Qemu-FNIRSI-1013D-Emulation-Screenshots

[pcprogrammer]

For those interested I'm back on reverse engineering the FPGA.

I have gained some more insights on how the routing in the Anlogic FPGA works and are currently writing code to create a net list based on this new found information. It is a quest for knowledge and not this particular design that I'm after. I do hope that the new found skills will enable me to reverse engineer the Hantek DSO2D15 FPGA design though, which will be far more complex and useful.

Not going to write about it in this thread but any update will be posted here: https://www.eevblog.com/forum/fpga/reverse-engineering-anlogic-al3_10-fpga/

The last post there is a question, but either no one knows an answer or no one cares enough to post a reply.

[illiac4]

This is great. Hope 1031D will get even better.

[marauder]

Hello,
I'm please that I joined this forum and community.
Big big thank you pcprogrammer for making firmware for this scope.
And my question. My 1013d seems to subtract ~1 VDC reading on CH1, no amount of "calibration" or auto set helps, on low voltage readings obviously is more significant.
I've checked pecostm32' analog input schematic and I'm wondering what I should look for to correct this error. I already resoldered virtually everything around analog input, that didn't help.
Do you have any suggestion what to look for? Maybe it is just some resistor picking up reference voltage with incorrect value?
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[pcprogrammer]

Since this is a static difference between the two channels I would advise to measure the voltages going into the ADC and see what the differences are between the two channels.

So measure ANALOG1_ADC_INPUT and ANALOG2_ADC_INPUT and compare them. Then check ADC1_OFFSET and ADC2_OFFSET after the smoothing filters, so on pin 3 of the ADC's.

Also good to know if this behavior is also there with the original firmware?

[marauder]

Thank you pcprogrammer for such fast response.
Yes, the same behavior is with the original firmware.
I'm sitting down soon with tools and do measurements and you know.
Thanks!

[pcprogrammer]

You are welcome.

The fact that it behaves the same with the original firmware shows that it is in the hardware. So best is to compare between the two channels with a DMM.

There is a difference between the OFFSET voltage handling in the original firmware and my firmware. Best use mine when doing the measurements.

Success with your quest

[marauder]

Findings:
1. I understand that ANALOG1_ADC_INPUT and ANALOG2_ADC_INPUT is ANALOG1_AC_DC and ANALOG2_AC_DC on schematic, PIN1 on SSR MOSFET. They are the same, 1.09V
2. There are differences in resistor's values compared to schematic in filter section but that's not important I believe.
3. There are differences on RS8751RF comparators:
- CH1: "+" 1.10V,  "-" 1.02V,  "OUT" 1.13V
- CH2: "+" 1.19V,  "-" 1.23V,  "OUT" 1.23V

That seems like consistent 0.1V difference. Do you think that something in filters messing this up? 

[pcprogrammer]

No you are wrong.

ANALOG1_AC_DC is an output from the FPGA to control the KAQY214STLD "relay" to switch between AC and DC mode.

On the right side of the schematic you can see the signals I pointed to. (See them marked below) These are the outputs of the operational amplifiers.

As long as the resistor values are the same on both channels that won't be the issue.

What you call comparator, I call operational amplifier, and that is what it is here. The fact that there is a 0.1V difference between the two channels might be the problem indeed. The ADC measures the difference between the offset voltage on pin 3 and the input signal on pin 2. (See Scope_Data_Acquisition schematic) So measure the voltages on the ADC input pins against ground and report these back. Then it is possible to figure out what is causing the problem.

You are not looking for a 1V difference between the two channels, because the reading from the ADC is scaled in the software. For a zero reading on the display the input on the ADC should be equal to the offset voltage.

[marauder]

Comparator - its actually a Polish name for operational amplifier  so apologize for that.
Found ANALOG1_AC_DC and ANALOG2_AC_DC.
What I noticed is that K1/K6 relay is on or off depends on V/div, and when it is in off state, VRF1 voltage (1.23V) drops on CH1 after the resistor R70 or PIN 2,7 of K1, VRF1 does not drops before R70 (directly on VRF1). This is not happening on CH2.
1. 50mV/div    (K1/K6 off),  ANALOG1_ADC_INPUT 0.67V, ANALOG2_ADC_INPUT 1.23V
2. 100mV/div  (K1/K6 off),  ANALOG1_ADC_INPUT 0.67V, ANALOG2_ADC_INPUT 1.23V
3. 200mV/div  (K1/K6 on),  ANALOG1_ADC_INPUT 0.95V, ANALOG2_ADC_INPUT 1.23V
4. 500mV/div  (K1/K6 off),  ANALOG1_ADC_INPUT 0.99V, ANALOG2_ADC_INPUT 1.23V
5. 1V/div         (K1/K6 on),  ANALOG1_ADC_INPUT 1.11V, ANALOG2_ADC_INPUT 1.23V
6. 2.5V/div      (K1/K6 off),  ANALOG1_ADC_INPUT 1.17V, ANALOG2_ADC_INPUT 1.23V
7. 5V/div         (K1/K6 on),  ANALOG1_ADC_INPUT 1.20V, ANALOG2_ADC_INPUT 1.23V

CH1 looks messy...

[pcprogrammer]

Analog electronics is not really my thing so I don't know how the amplifier works in this setup, but the K1 relay seems to change it from an inverter to an inverting amplifier. (Difference is -1x amplification versus either increasing or decreasing the signal with a variable rate whilst also inverting it)

When K1 is connecting pin 6 with pin 5 R69 is shorted and the offset from VRF1 is disconnected making it an inverter. When pin 6 is connected to pin 7 the feedback loop has R69 in it and the - input of the opamp is set at an offset via R70 to VRF1. The other two relays K2 and K3 select between the different input resistor combinations.

The fact that you see these differences between the two channels shows indeed that channel 1 has a defect. What causes it I don't know. Might be a faulty capacitor, resistor or even the opamp. One way to check if it is the opamp is to swap the two and see if the defect shifts to channel 2.

[marauder]

After the last measurements I started to get the feeling that its the opamp.. you really confirmed that.
I'll order new opamps and replace it on CH1. It will take a few days (delivery, weekend...) and I'll let you know how it went.
Most of all, thank you!
 

[marauder]

Dear @pcprogrammer
I did it! It took a long time because I had to buy OPA356 (OAAI)  opamp from China (local, heavily overpriced seller failed to deliver it), I have replaced opamp doing watchmaker job, and the scope is working like a charm.
Thank you very much for your assistance and help.
Thanks!

[MilesStarr]

This has been a handy little gadget, but I've run into a problem that I don't understand.  Maybe updated firmware would fix this, but before I go opening up the device to do this I wanted to see if anyone else ran into this.  Maybe this isn't addressed in the current firmware changes at all?

The save waveform function seems to work well against the autoscaled calibration.  I took the .wav file, used https://github.com/roberttidey/FNISR1013DScope to dump it into a JSON, and copy it into Excel to figure out the fiddly bits.  Beautiful.

Next I take a saved waveform while I'm looking for pulses on a 1 S/div timescale to then measure the pulse frequency and the data in the JSON doesn't show the pulse I can clearly see that is a few pixels wide on the screen.  So is there anything to be done or just use the obvious answer that this is just the wrong tool for that job.