'KROT2-XM' (mole), new project Xmega32

[Tepco]

It is applied normal display 1602 (+5 volts). Specifically to buy a 3.3 volt is not necessary. Components C26, 27, D1, 2, R19, 27 form a negative voltage and allows you to control the contrast of the "menu" of the instrument. Backlight unit, is also included in the "menu".

Perfect, just forgot software contrast adjustment. Also, managed to find one blue Winstar display on some prototype, (very good one, locally cheaply available from http://www.mikroe.com/rs/store/ for about 6E) fits perfectly. I have some old obsolete large displays, leftover from some production run, but they wont work from 3.3V, wont fit physically, writeoff. I made PCB film on Linotronic from original .lay file, DIP version, will try to make board using photo-etching. My friend use PDI programmer, no problem wit that, now just chip to arrive. Locally I cant find any 44pin Xmega, just larger chips. This should work with Atxmega 128A4 too? (just in case I find one) I want to try this in original version first, but having very good experience with old Krot, I expect very good results. Many thanks to author for sharing this project, now this is probably most advanced DIY VLF design I aware of. (not built Quasar, but I will, so I don’t want to make any conclusion). This is great improvement of “technological level” on this forum, still heavily relying on LM339 and 358 and 40xx stuff. At the end, everything will be sorted out in software. Just, I will not be involved, I do write, but just HATE programming for hobby, you will sooner see my vacuum tube design here than any code. Best regard.

[smity]

Do not buy a display on 3.3V! This display operates on 5 volts.

[WM6]

DIP (IC) version PCB

DIP (IC) version PCB of KROT-2 XM

[smity]

That's Mole-2 works in nature ...

[Tepco]

Here is the one, in spirit of original. I will not post any file until i'm not sure everything is working and 100% corrected.

[WM6]

Here is the one, in spirit of original. I will not post any file until i'm not sure everything is working and 100% corrected.

HI smity can you check this errors found by our friend Geo on DIP PCB version in comparison with schematic:

1. R27, at schema is connected to gnd, at pcb is going to 3.3V.
2. Name of C6 and C7 must reversed, but no problem because have the same value.
3. Potentiometer for volume is n't there, but maybe this is solved by software.
4. R26 at pcb (beeper), is not present at schematic too.

[WM6]

Here is the one, in spirit of original. I will not post any file until i'm not sure everything is working and 100% corrected.

Hi Tepco, do you know what are differences between this two ground mark in KROT schematic?



Seems that it is not about analog/digital ground cause opAmp and Xmega have the same ground mark?

[Geo]

The GND with 2 lines is GND line filtered by L=10uH.
Its only my opinion...

[Geo]

S4 at DIP pcb is S3 at schematic
S3 " " " " S4 "
S1 and S2 are OK.
I think that this is not problem....

[Tepco]

I don’t have working unit yet (waiting for chip to arrive) but seems like this: Analog ground about RX input is carefully separated on PCB from rest of the circuit (digital ground), no idea how important this can be, but this is more correct way, I copied it. Switch position is nor important at this point, can be changed if needed. R27 in contrast adjustment most probably goes to 3.3V, this part for software contrast adjustment and negative voltage seems to be added later on schematic, anyway easy to reconnect, may vary with display type too. Volume pot is omitted, fixed resistor divider is used (volume adjustable in software). R26 is good to keep, to unload U4, depending on beeper or speaker type. Issue with C6,7 is OK, looking at datasheet 0.1uF should be enough for given frequency but there is enough room for modification on PCB to fit bit larger (also 200mil) 1uF. Link to Sprint6:


http://www.4shared.com/rar/DIUDIR59/..._04242013.html

[WM6]

Hi smity

where did you get scan of DIP PCB layout in your post #19?

DIP layout in .RAR file in your post #19 are not the same:



Which layout is more correct?

[Geo]

I don’t have working unit yet (waiting for chip to arrive) but seems like this: Analog ground about RX input is carefully separated on PCB from rest of the circuit (digital ground), no idea how important this can be, but this is more correct way, I copied it. Switch position is nor important at this point, can be changed if needed. R27 in contrast adjustment most probably goes to 3.3V, this part for software contrast adjustment and negative voltage seems to be added later on schematic, anyway easy to reconnect, may vary with display type too. Volume pot is omitted, fixed resistor divider is used (volume adjustable in software). R26 is good to keep, to unload U4, depending on beeper or speaker type. Issue with C6,7 is OK, looking at datasheet 0.1uF should be enough for given frequency but there is enough room for modification on PCB to fit bit larger (also 200mil) 1uF. Link to Sprint6:


http://www.4shared.com/rar/DIUDIR59/..._04242013.html

Hi Tepco.
Do you have any crack file for layout6.0???

[Tepco]

Just install it, everything is sorted out.

[6666]

http://www.4shared.com/rar/DIUDIR59/..._04242013.html

What do you click to actually get the file, so far all that site wants to do is download new drivers or want me to sign up ?

[Tepco]

Register, you need to have account to download anything