VDI-RODERICO

[Albdelafar]

waltr and roderico :
I did my PCB of V2.2 mixing the universal display PCB from waltr for my oled display and the VDI from roderico with 3.3V power suply. But somme PIC18 pin's have diff?rent assignement like pin 13 and 14. So did the .hex roderico uploaded for PIC18F26K22 will work on the two configuration or I need to choose one ?
Same I do not understand where to add Q1 on the waltr universal display PCB.
I join the two diagramme here
Univer_Display.pdfvdi-sch-2.2.pdf
Thanks.
Alban

[roderico]

I don't know what it does, can it be used for pulse detectors? How do I connect my machine and why there is no display picture?

pulse induction detectors have a different principle of operation, this only works with vlf detectors

[roderico]

waltr and roderico :
So did the .hex roderico uploaded for PIC18F26K22 will work on the two configuration or I need to choose one ?

PIC18F26K22 firmware only works with the pin configuration of vdi-sch-2.2.pdf, SDD1305 connected as the ST7567, you would need to recompile it from source if you use a different configuration after updating the source code...

[waltr]

waltr and roderico :
I did my PCB of V2.2 mixing the universal display PCB from waltr for my oled display and the VDI from roderico with 3.3V power suply. But somme PIC18 pin's have diff?rent assignement like pin 13 and 14. So did the .hex roderico uploaded for PIC18F26K22 will work on the two configuration or I need to choose one ?
Same I do not understand where to add Q1 on the waltr universal display PCB.
I join the two diagramme here
[ATTACH]50313[/ATTACH][ATTACH]50314[/ATTACH]
Thanks.
Alban

Q1 is not used on an OLED display. This is for Dimming the Backlight of a standard LCD display.
If you need Backlight control then an Q1 and the resistor between pins on J5, labeled 'back light'. Connect Q1's base to a free PIC pin.
Best pin would be PortC1 or PORTC2 since these are the CCP outputs (PWM module). Then move SW1 or 2 to PortC3.

PIC18F26K22 firmware only works with the pin configuration of vdi-sch-2.2.pdf, SDD1305 connected as the ST7567, you would need to recompile it from source if you use a different configuration after updating the source code...

Correct.
I modified the source code to change the Pin-outs.
I designed the universal display board since I have a few projects with different displays that were on protoboards.
I currently have a 2x20 line alpha LCD on one with a PIC16F873 and running as an SPI Slave/display controller, a TFT 400x320 color display with a PIC18F26Q10 on another and the OLED and a PIC18F25K22 on this VDI code.

Easiest thing to do to start is simply wire the OLED display to the Pins Rederico uses with the Hex file. Then you can see if the display works.
Later learn MPLABX and PIC C programming then modify the source code for different pin out.

[Albdelafar]

Ok I will start with roderico's PCB then !! I will just replace MCP604 by two MCP602 I bought them when only one was necessary.
Thanks for your time !!

[Albdelafar]

I did The sprint layout for roderico VDI 3.3V and two MCP602 instead of one MCP604. I added a SIP connector for switches if you want to put them on another board like the screen PCB with a more simple connection. I did the drilling to correspond to my IDX PCB to permit an easyest integration too.If someone could verify that there is no mistakes on PCB will be cool. Do not forget I'm new on this type of exercise. If it's good I will put the Gerber here for both IDX and 3.3V VDI.Thanks

[roderico]

in principle it looks fine, however IMO is not a good idea to share C8 between U1 and U2, you should add a decoupling capacitor for each MCP602 and place them close to pin 8, check again U1, U2 connections just in case

[waltr]

Looked over the layout Albdelafar and beside what Rederico said I didn't see anything majorly wrong.

Hint: I have many times soldered a by-pass cap to the power pins on the bottom of the PCB. This way the cap is directly on the power pins. The way you have C8 it has a long trace to connect and this does not help kill high frequency noise or provide good by-pass of power to the op-amps.

[oden]

thank you Roderico

[roderico]

when using MCP604 (or two MCP602) the input is in phase with the output, but 180 phase shift when using only the MCP602, so the trigger channel should be the opposite, i.e. if trigger channel was set on the rising edge in v2.1 then you would need to change it to the fallen edge for best performance, this can be seen in the scope view, the attached picture shows MCP604 version triggering on the rising edge of channel X this might be more stable but for weak signals it might be better to trigger on the fallen edge instead

[roderico]

I forgot to fix a rounding error in time base that causes last 8 values not to be shown in scope view in v2.2, I have rebuilt glcd firmwares but not changed version number since it is a minor bug and no update is needed but the fix is included in v2.2

[Albdelafar]

Thanks for advices and for this fix roderico !!
Do you think I can put C8 like this on the bottom side like waltr said ?

You use ceramic capacitor for by-pass right ?

[roderico]

of course, waltr explained it better than me and he also has a working SDD1305/3.3V version, multilayer ceramic capacitors for C7 and C8 would work fine, see picture of v2.1 as an example https://www.geotech1.com/forums/atta...8&d=1562773837 , you can also make some room to place C8 capacitors close to power pins

[waltr]

Thanks for advices and for this fix roderico !!
Do you think I can put C8 like this on the bottom side like waltr said ?
[ATTACH]50343[/ATTACH]
You use ceramic capacitor for by-pass right ?

Ceramic caps-yes.
I was not thinking of adding holes with the caps on the bottom. Nice idea.
I was thinking of simply soldering the caps to the op-amp pins that extend through the pcb. I like your idea.
The caps can be bent over to lay onto the pcb reduce the height below the pcb.

Having the caps directly on the op-amp pins is best as it reduces the amount of trace length which would add resistance and inductance.

[waltr]

I forgot to fix a rounding error in time base that causes last 8 values not to be shown in scope view in v2.2, I have rebuilt glcd firmwares but not changed version number since it is a minor bug and no update is needed but the fix is included in v2.2

Is this bug in the 2.2b2 code?
And if yes which code module?