Modification of software and hardware

OldHunter
Posts: 3
Joined: Sun Jul 08, 2018 9:11 am

Re: Modification of software and hardware

Post by OldHunter »

@toshi
Thank you, was right. Sorry for the mistake.
I had a quick look in the "Command.c " file.
The values for Threshold_High and Threshold_Low explain the missing of the DC selection on the LCD.
0x300 is a value 0f 3*256* /4096*3.3=0.62V and 0x900 gives 1.86V at CPLSEL. The divider with the R17/R18 gives 2.5V (5V/2).
So the mid-position of the coupling switch gives 2.5V and the window is 0.62V-1.8V ???
I wonder how it worked originally ????
Or does the "tmp1 = ADC_Poll(ADC2, 5);" give other result than the raw 12bit ADC value?
Rudolf
Posts: 4
Joined: Thu Oct 12, 2017 5:15 am

Re: Modification of software and hardware

Post by Rudolf »

OldHunter wrote: @Rudolf
You can fix the problem with the "no DC" appearance by changing the R18 resistor
from 10K to 5K6. See Schematic _150analog.pdf near SW1A
Hello OldHunter,
Since firmware version 113-15001-110 the problem with the missing "DC" appearance on the LCD screen is fixed.
Regards, Rudolf
OldHunter
Posts: 3
Joined: Sun Jul 08, 2018 9:11 am

Re: Modification of software and hardware

Post by OldHunter »

Hi Rudolf,
Thanks for the reply.
I insist that this is a bug here, also in the newest firmware from JYE. They should have a look.
But obviously it still works. Why? my guess/explanation ist that something is wrong with the ADC_Poll() function.
The second argument ( ,5) is the number of samples to build an average? i cannot find any description of that function (propably in the closed libraries from JYE).
But i think it does not execute correctly, gives a wrong value, which in turn hides the "wrong" thresholds.
I guess that the R18/R17 divider was fed from 3.3V and at some time it changed to 5V and the divider was not corrected accordingly.
Best Regards
echase
Posts: 4
Joined: Fri Aug 03, 2018 5:49 pm

Re: Modification of software and hardware

Post by echase »

SDC16465.JPG
Have any of the interesting hardware and software mods mentioned here fed into the latest official product? I have just bought the attached and am wondering how many of these mods I could to do. For instance my analogue PCB layout looks different to the photos in Toshi’s ZIP file so maybe JYE have already made some of these reduction of noise mods.

What does the 03DA at the top right of screen mean? Checksum?
alphaseek
Posts: 85
Joined: Thu Jan 19, 2017 5:24 pm

Re: Modification of software and hardware

Post by alphaseek »

I think Toshi's mods apply to a very early version of the Shell, both hardware and software. Some of the software changes have been encorporated. I think the current version doesn't need any mods unless you want to add a battery or internal USB adapter.
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