IDX-PRO+VDI

[dfbowers]

Hi
I am interested for this nice project specially about VDI section. Many thanks.
However I have a big problem about PIC micro controller 16F88 or 16F690. Unfortunately in my country, not any of these chips could be found!
Can you suggest me any solution? I think VDI may be reprogrammed with ATMEGA chips that are very common, or at least for another common PIC micro.
Thanks

It can be done easily. Maybe use an Arduino UNO to program an ATMEGA328P?

http://www.geotech1.com/forums/showthread.php?18958-Arduino-based-VDI!&p=147090#post147090

[hamidrt]

Thank you dfbowers
Of course I can find many atmega ics. But I need a specific hex file or source code for this project! It seems that vdi is different. Are these 2 project the same? Which of them may be better?

[dfbowers]

Thank you dfbowers
Of course I can find many atmega ics. But I need a specific hex file or source code for this project! It seems that vdi is different. Are these 2 project the same? Which of them may be better?

Can you be a little more "specific" about what specific hex file you are looking for? Experiment #1 does the same thing.. calculates the arctan between the two channels. If you have an Arduino, just load it and away you go.. It runs just fine on an Arduino Micro too - The same size as a stick chewing gum. The only thing I am missing are a pair of op amps to isolate the Arduino, although it works just fine by itself.

[hamidrt]

OK dfbowers. In fact I have not Arduino Micro but I can program a ATMEGA from source code. I see you provide some source code in C language. I hope to compile it by CodeVision for Atmega8 with some changes in pin configuration and use TL072 for X,Y input.
You are right. VDI is only a math calculation on phases. So I should do it myself with your source. Is it true?
Also, I see video of your project in youtube. Great job! Specially about name of metals that appeared on lcd.
Thanks

[dfbowers]

The nice thing is that you can easily change parameters, especially with sampling. My next step was to add a few subroutines to average coil sweeps to improve accuracy even more. I have done some actual field testing and the only drawback is that the lcd is difficult to see in sunlight. It would be nice to see someone take the whole experiment to the next level.
Don..

[spookyspy]

Well, I'm experimenting with a pic processor to calculate the VDI by direct sampling of the signal. Thus not using the x/y. My goal is to use only the TX and RX part and do all the logic in the processor. So discrimination and all other logic will be in the software. As far for now i'm able to calculate the fase and signal strength. On my youtube video http://youtu.be/c-W6HwcI-Ec you can see the raw results. Notice some fluttering but thats because i'm using a pc based signal processor with a unamplified signal straight into the pic. Some opamps needed here to push the signal up to 5 volts or so. Sampling was the hard part, all other logic is just programming the software. to be continued.

[eduardo1979]

Well, I'm experimenting with a pic processor to calculate the VDI by direct sampling of the signal. Thus not using the x/y. My goal is to use only the TX and RX part and do all the logic in the processor. So discrimination and all other logic will be in the software. As far for now i'm able to calculate the fase and signal strength. On my youtube video http://youtu.be/c-W6HwcI-Ec you can see the raw results. Notice some fluttering but thats because i'm using a pc based signal processor with a unamplified signal straight into the pic. Some opamps needed here to push the signal up to 5 volts or so. Sampling was the hard part, all other logic is just programming the software. to be continued.

Very interesting! I wish you much success with your project. Greetings, Eduardo.

[Nicolas]

Well, I'm experimenting with a pic processor to calculate the VDI by direct sampling of the signal. Thus not using the x/y. My goal is to use only the TX and RX part and do all the logic in the processor. So discrimination and all other logic will be in the software. As far for now i'm able to calculate the fase and signal strength. On my youtube video http://youtu.be/c-W6HwcI-Ec you can see the raw results. Notice some fluttering but thats because i'm using a pc based signal processor with a unamplified signal straight into the pic. Some opamps needed here to push the signal up to 5 volts or so. Sampling was the hard part, all other logic is just programming the software. to be continued.

Hi Spookyspy

Nice job ..can you put that in Geotech forum my congratulation

[jap]

Hi spookyspy
-Good work,,,,try to use Proteus 7.10 will help you a lot in completing the project and the possibility of experiment and modification.
best time
j.

[Daxxin]

Just finish to etch idx pcb ..made 2 boards ..i have printed from WhitesIDX.lay file it was the correct version? i seen some differences with
silverdog schematic.

[joop]

I just finished building the IDX-PRO using the PCB from silverdog's shop. I discovered 2 small bugs on the silkscreen. There are 2 BC547's drawn on the component side which replace the BC237 in the original schematic. Q2, part of the oscillator has E and C swapped but the transistor housing is correct. Q3, just before the last audio stage has the correct E, B and C but the housing has been rotated 180 degrees.

Here's my finished build. Next I plan to start on the VDI.

[joop]

By the way, anyone know how to adjust VR3 (phase)?

[reiv]

Post #178, by the way those type of cappacitors it is not good choice, better will be MKT type.

[joop]

Thanks, will give it a try. The MKT I have are 7.5 mm pitch and the board needs 5 mm. Guess I will need to drill some extra holes.

[reiv]

IDX PCB is max minimalize, soe in some places I think there will be no space to put 7.5mm caps even You drill another holes, maybe simplest way is to buy 5mm they are not soe expensive.