FNIRSI-1013D "100MHz" tablet oscilloscope

[Atlan]

Autoset for channel 1 if in DC mode with offset. Try the functionality. v0.018f only test

[tokar]

https://youtu.be/nsCt2JHbD0g

Thanks for the work you've done. This is much closer to the original firmware. But the dynamic range is small, or the switching points need to be shifted. I'll post later how it should be.

[tokar]

For clarity, I will start with the previous version.
https://youtu.be/T1aCo7WfnYU

All modified versions, from 0005 to 0017d, do not work with signals with a DC offset. Here are some examples:
1. Set the gain to 50mV/div. We apply a sine wave without DC offset, and increase the signal to the limit. We press auto set, and we get a gain of 100 mV/div, and an oscilloscope without limitation. We increase the signal again to the limit. We press auto set, and we get a gain of 200 mV/div, and an oscilloscope without limitation. And so on, that’s how it should work.
2. Enter the DC offset (1:05) to limit the sine from above. Click auto set and get a gain of 100mV/div!!! (was 1v/div), and oscillogram with limitation. I remove the DC offset (1:53). Press auto set and get a gain of 1v/div. And this is the situation at any gain.                                                                           
I suspect that they were too clever with the ADC transformations. It turns out that the measurement of the signal value for working out an auto set does not occur in a complex manner (AC + DC), but only according to the “residues” from the sine limit. Since in AC mode everything works as it should.                                                                       
                                     

[tokar]

In this video, the behavior of the original FNIRSI 1013d firmware under similar conditions, as in the video, post above. The correct operation of the auto set function and the choice of channel gain are clearly visible.

https://youtu.be/CyLg-Wa5yF4

[Atlan]

You brought the error or request for a problem in DC mode. After the release of version 0.017d (that's why no one solved it in previous versions)

I started working on it from version 0.018. Current BETA version for use v0.018g (dc shift applied to ch1 and ch2 channels)

There was already talk about the fact that the old programmer introduced a software shift of the signal.
Therefore, the signal shift due to DC offset is currently solved purely by software. And that's why it has a limited dynamic range.
Therefore, the change of the color of the signal to red is supplemented if there is a limitation of the signal due to exceeding the range of the AD converter.

It's a beta version, so I don't solve some calculation imperfections such as the 50 trigger, and not aligning to the center of the grid

[Atlan]

Can someone measure voltages in DC and AC 50(60)Hz mode.  With the implementation of the check with a multimeter, for example (aneng8002) or another somewhat accurate one.  It would be appropriate if it was at least 4 oscilloscopes.  2 old 2 new versions.  Measurement on both channels separately.  On the range of 100mV, 200mV, 500mV, 1V, 2.5v and 5V.  Use the following voltages for measurement: 50mV, 100mV, 250mV, 500mV; 1.25V; 2.5V.  Do not forget to calibrate the oscilloscope and the probe in 1x mode before measuring. 

Well thank you. 

Would you be interested in an expanded menu of channels for choosing a specific sensitivity value?  It will be just small buttons.

P.S. HAPPY AND MERRY CHRISTMAS.

[tokar]

I only have a simple Chinese analog generator that produces a sine wave of only 2.3V RMS (VPP = 6.6V). I can’t set the voltage and frequency accurately, the error is 0.1-0.2V, 0.1-0.2Hz. If it suits you, I can make a video. Or take a photo?
And questions arise:
1. Specify the firmware versions (old, new) that should be used for measurements.
2. Is the 50 mV range not needed?
3. Which input mode (AC or DC) should I choose when measuring AC?
4. What is the measurement order? Example: select the 5V range, and sequentially apply a signal of 50, 100, 250, 500mV, 1.25V, 2.5V, until a limitation appears. Then we move to the 2.5V range and repeat the signal.

[Atlan]

1.software version from 0.006 to 0.0.18j are all the same.
2.50mV is produced by the software
3.Let's simplify it, measure voltage in DC mode
4.
Range 100mV measured voltage 50mV,
range 200mV measured voltage 100mV,
range 500mV measured voltage 250mV,
range of 1V measured voltage 500mV,
range 2.5V measured voltage 1.25V,
range 5V measured voltage 2.5V.

All you need is a 3V power source and some potentiometer and a precise measuring device on which the voltage is set, for example 50mV, then the measured voltage is described from the oscilloscope, for example 47mV

Just write the values on the forum.
50mV - the oscilloscope showed 47mV ......

[tokar]

Range    |       Uin        |     CH1        |     CH2
              |                    |Urms=Uavg | Urms=Uavg
----------------------------------------------------------------
100mv    |   50,11mv   |     54mv      |  54-58mv
----------------------------------------------------------------
200mv    |   100,05mv | 100-108mv |  108mv 
----------------------------------------------------------------
500mv    |   250,1mv   |     250mv    |  250-270mv
----------------------------------------------------------------
   1v       |   500,1mv   |     500mv     |  500mv
----------------------------------------------------------------
  2,5v     |   1,2501v    |1,20 - 1,30v  |  1,20v
----------------------------------------------------------------
   5v       |   2,501v      |      2,5v        |   2,4v
----------------------------------------------------------------

[tokar]

It is not yet clear why, even with the input connector disconnected, the voltmeter shows an offset. 
Moreover, it decreases with increasing sensitivity.
https://youtu.be/OMuJZHylKOM?feature=shared

[Atlan]

The relay is powered by 3V res from the same voltage as the FPGA, AD converters and operational amplifiers.  They have some pickup and when they are turned on and off, the voltage changes, which affects the track.

[tokar]

But on the original fnirsi 1013d, under the same conditions, this effect is not observed.  All voltmeter fields show "0".

[Atlan]

The original firmware ignores the change in 2 or 3 bits.  Try it yourself, take a low voltage source, for example 300mV.  Connect 100k to the potentiometer and connect the oscilloscope to the runner.  And find out that on the range of 100mV DC, the oscilloscope starts to show from a voltage of 35mV.

The original firmware is full of such things, it shows beautiful patterns that do not correspond to reality.  The difference is probably the same as between a painted model and one who gets up in the morning.

[tokar]

First I checked - everything is as you say.  Then I remembered that I had already read about the included digital filters.  Thank you for the clarification.

[Atlan]

Editing of the displayed data from the voltage cursors. added Y1 , Y2 and dY. color-coded for channel 1 and channel 2

Small mistake in v0. 018j, but it should be OK version 0.018k

[Atlan]

tokar: try v0.018l and try to measure the values again to see if the accuracy improves.

[tokar]

Range    |     Uin          |     CH1          |     CH2   
---------------------------------------------------------------
100mv    |   50,11mv   |   48-50mv     |   50mv   
---------------------------------------------------------------
200mv    |   100,05mv |    100mv       |  100mv   
---------------------------------------------------------------
500mv    |   250,0mv   |     260mv       |  260mv   
---------------------------------------------------------------
   1v        |   500,1mv   |  500-520mv  | 500-520mv
---------------------------------------------------------------
  2,5v      |   1,2501v   |      1,15v        |  1,35v   
---------------------------------------------------------------
   5v        |    2,500v    |       2,4v         | 2,6-2,7v 
---------------------------------------------------------------

[Atlan]

Ok, thank you.  I will do the calibration option.  For channel 1 and 2. Calibration at the upper end of the range to reduce the influence of interference.

It will take some time.

[Atlan]

See next

[tokar]

Original solution.  Maybe it will be more convenient than the standard one.  Is this an addition to the main attenuator?  Or will the sidebar be removed in the future?

[Atlan]

The problem with this solution is that you can't see the setting change on the progress.  But for known values ​​of the measured voltage, it will speed up the setting.
There are no plans to remove the sensitivity setting menu.

[tokar]

I just wanted to draw your attention to the fact that there is no need to abandon the side menu. A similar menu was used in DSO112a (Fnirsi, JYE Tech).  Not very comfortable.  Open the menu, select sensitivity, exit to the screen.  And see that you missed.  And repeat everything from the beginning.

[gadak]

Hi, I bought a new version of the oscilloscope, I am posting the file for the touchscreen. When I did backup according to the instructions, a message appeared on the display special touch panel detected.

[Atlan]

  firmware v0.019a quick menu sensitivity



display special touch panel detected. If a flood programmer appeared here, he would answer you as soon as possible. Try to be patient. He reads it here sometimes.

Have you tried opening your firmware backup in the loader program and checking the values in the touchscreen tab?
I have never done it, and as always everything at my own risk.

[pcprogrammer]

Hi, I bought a new version of the oscilloscope, I am posting the file for the touchscreen. When I did backup according to the instructions, a message appeared on the display special touch panel detected.

Thanks for uploading the file, and welcome to the forum.

Hope you enjoy your new scope.

Edit: @Atlan. gadak used the flash firmware backup program I wrote and it signaled that he has a scope with the touch panel configuration I was after when I did the reverse engineering and new software development. I, at the time, f'ed up my second scope that has the same touch panel.

Since the first release of the new firmware that is loaded onto the SD card, the touch panel configuration is no longer written to the touch panel. In case of reversed touch coordinates the other hidden configuration file can be modified, like one of your pictures shows a program for I guess.