Products > Test Equipment
New bench scope - Fnirsi 1014D, 7", 1GSa/s
Kean:
"R1" marking could be CJ3401 P-Ch MOSFET 30V 4.2A
https://lcsc.com/product-detail/MOSFETs_Changjiang-Electronics-Tech-CJ-CJ3401_C13799.html
dmitrkov:
https://www.s-manuals.com/smd/r1
joseph4511:
yes its a p channel mosfet, 5v across drain to source
pcprogrammer:
Hi Yusef,
I thought up another test to see if it is possible to load the first bit of the DRAM.
Use sunxi-fel to set the display engine to use the first part of the DRAM:
--- Code: ---sudo ./sunxi-fel writel 0x01E60850 0x00000000
sudo ./sunxi-fel writel 0x01E60860 0x00000004
--- End code ---
Then load the attached image data to the memory with:
--- Code: ---sudo ./sunxi-fel -p write 0x80000000 scope_image.bin.txt
--- End code ---
You should see the image building on the screen while it loads.
I also found the reason why the screen flickers when the boot with FEL option is used. The FPGA controls the brightness of the screen with PWM. For this to work the FPGA needs a clock, and that is what is missing. The F1C100s has to initialize the clock synthesizer for this. I'm still looking through the original code to find where this is done.
Another thing I discovered is that the GD32E230 is used to control the power. It generates a hold signal to keep the P-FET active. When the power button is pushed again it is signaled by the GD32E230 and it then releases this hold signal.
Most of the schematic is similar to the 1013D. One difference is that the MCU and FPGA use a separate 3V3 power source. Have done quite a bit already but still need to do the GD32E230 part, which is new since the 1013D just has a touch panel.
pcprogrammer:
Schematics are done.
Did not check the capacitors and only gave them an identifier. Also not in a nice logical order since I used the 1013D schematics as a starting point.
There are some changes compared to the 1013D but nothing major. The FPGA connections changed a bit and the power supply setup is different. The analog input is mostly the same. They used 3,3V for the opamps instead of the 2,5V used in the 1013D.
The buttons on the front panel are scanned in a 6x6 matrix, but they did not use diodes so no usage of multiple buttons at once. No need for it so no problem. The rotary encoders all have separate connections on the GD32E230.
A bit of a shame that they did not add a battery and an extra diode and made use of the RTC that sits in the GD32E230. Would have given the saved files a proper time stamp. Due to the fact that the resistor networks used for rotary encoders are sourced from the GD32E230 3,3V supply it is a bit harder to make a modification. It would drain the battery at a higher rate then needed.
I'm going to rename the 1013D hack repository and upload the 1014D material there.
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