DLO-138 OScope

What are you developing?
mausi_mick
Posts: 148
Joined: Fri Aug 12, 2016 1:40 pm

Re: DLO-138 OScope

Post by mausi_mick » Thu Nov 02, 2017 3:14 am

Hi rexnanet,

I have modified the program, now the offset by changing gain is ok. The noise - I think - is from the preamp without compensation. I need some picoFarad ...



[url]https://youtu.be/vbiXGKW42pU/url]

mausi_mick
Posts: 148
Joined: Fri Aug 12, 2016 1:40 pm

Re: DLO-138 OScope

Post by mausi_mick » Sat Nov 04, 2017 5:13 pm

I have the preamps modified, here a picture:

DLO138_ILI9341_SPI_Preamps_with_TL072_and_MCP6S91.JPG
DLO138_ILI9341_SPI_Preamps_with_TL072_and_MCP6S91.JPG (44.07 KiB) Viewed 269 times

mausi_mick
Posts: 148
Joined: Fri Aug 12, 2016 1:40 pm

Re: DLO-138 OScope

Post by mausi_mick » Tue Nov 07, 2017 7:02 pm

now the second preamp is nearly ready, I changed the TL072 in the first stage with the MCP6022 (R.R) because supply-voltage is only 5V.
The noise is from not perfect shielding . ?

DLO138_ILI9341_SPI_DualPreamp_MCP6022_MCP6S91.JPG
DLO138_ILI9341_SPI_DualPreamp_MCP6022_MCP6S91.JPG (45.75 KiB) Viewed 231 times

mausi_mick
Posts: 148
Joined: Fri Aug 12, 2016 1:40 pm

Re: DLO-138 OScope

Post by mausi_mick » Sat Nov 11, 2017 2:16 am

Now I have made a new pcb for the maple-mini in the same size with the 2.8" display includes 5V supply and the MCP4822 DAC.

It is nearly ok, butI have eliminate the DAC beacause I have to change it from 3.3V to 5V like the other devices (PGA's) on SPI-2.

And I have to make something with the trigger ...


A new video: https://youtu.be/3KJTmGfGuTA

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rexnanet
Posts: 205
Joined: Wed Mar 16, 2016 10:34 am

Re: DLO-138 OScope

Post by rexnanet » Sat Nov 11, 2017 8:35 am

Nice work!
3.3V to 5V: why are you mentioning SPI? 3.3V SPI should work with 5V slave if you ignore MISO line.
MCP6022 doesn't have a great BW but should be enough.
Is your trigger done in SW? If so it should be easy.

mausi_mick
Posts: 148
Joined: Fri Aug 12, 2016 1:40 pm

Re: DLO-138 OScope

Post by mausi_mick » Sat Nov 11, 2017 11:08 am

hi rexnanet,
the problem is solved,
It was a "design" error on the pcb-layout, I connected CS to CLK, MOSI to CS and CLK to MOSI of the MCP4822.
Now all is ok and the offset for both channels works. And the encoders work smooth and soft.

Thanks !

mausi_mick
Posts: 148
Joined: Fri Aug 12, 2016 1:40 pm

Re: DLO-138 OScope

Post by mausi_mick » Wed Nov 15, 2017 2:50 pm

Now I have finished the most of the HW and fixed it on the front-panel.

The supply m( USB or 7,5V-12V DC) is on the left side. BTN4 and Reset-Button are on the right above the two encoders.

DLO138_ILI9341_SPI_backside.JPG
DLO138_ILI9341_SPI_backside.JPG (61.74 KiB) Viewed 148 times
DLO138_ILI9341_SPI_front_panel_With encoders.JPG
DLO138_ILI9341_SPI_front_panel_With encoders.JPG (52.58 KiB) Viewed 148 times

mausi_mick
Posts: 148
Joined: Fri Aug 12, 2016 1:40 pm

Re: DLO-138 OScope

Post by mausi_mick » Mon Nov 20, 2017 4:17 pm

Now I have tested an quadencoder on an Namiki motor, the phase difference is 90° :lol:


https://www.youtube.com/watch?v=GXj4ve7 ... e=youtu.be

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