Yes, I did the board myself. Just tested it today and found a solder bridge that I made, so that's why it's better to have professionally built PCB's. Then I found out that the 1 meg resistors were all bad (they were brand new, I've never had this happen in my entire life, but it happened). Then, the oscillator started working. With my homemade probe (DD - work in progress), the frequency is about 6.8 KHz, which I may trim down with additional capacitors to the needed frequency. Also, tried the soundcard oscilloscope and it works nicely (my oscilloscope is not available right now), and could null the probe just fine. I have not yet got to the shielding part, which from other users' experience might be a problem. I'll try and wrap it up by the end of the weekend.
As for your courageous endeavor, I applaud you. It is something I myself would try (and probably never finish, as usual), though my MCU's of choice would probably be some ARM M3's. I got used to them. Anyway, have you seen the KROT-2, here on forum. I think the guy did an excellent job with it and I will most certainly build one as soon as I'm finished with IDX. I think it's just great! He used an integrated low power power amp and also generated signal from adc. He used the same IC for speaker power as well. He has implemented a lot other functionalities (changing output frequency for different probes, etc). Perhaps use his ideas on your own design. He used an Atmel xmega, with which I have no experience, so another MCU, such as PIC might be nice.
Anyway, back to the topic. Does anyone have a wiring diagram for the DD coil that shows how it should be connected with the board. I'm mainly interested with shield wiring. Should the point of connection of the two shields be on the PCB or can I connect them together in the coil? Also, one RX wire goes to ground, should I also ground it at the PCB. This has probably been answered many times, but I couldn't find a definitive answer and there seems to be more than one approach on the subject. Are there any tested ones that just work? I'm grateful in advance for any answers I get.
As for your courageous endeavor, I applaud you. It is something I myself would try (and probably never finish, as usual), though my MCU's of choice would probably be some ARM M3's. I got used to them. Anyway, have you seen the KROT-2, here on forum. I think the guy did an excellent job with it and I will most certainly build one as soon as I'm finished with IDX. I think it's just great! He used an integrated low power power amp and also generated signal from adc. He used the same IC for speaker power as well. He has implemented a lot other functionalities (changing output frequency for different probes, etc). Perhaps use his ideas on your own design. He used an Atmel xmega, with which I have no experience, so another MCU, such as PIC might be nice.
Anyway, back to the topic. Does anyone have a wiring diagram for the DD coil that shows how it should be connected with the board. I'm mainly interested with shield wiring. Should the point of connection of the two shields be on the PCB or can I connect them together in the coil? Also, one RX wire goes to ground, should I also ground it at the PCB. This has probably been answered many times, but I couldn't find a definitive answer and there seems to be more than one approach on the subject. Are there any tested ones that just work? I'm grateful in advance for any answers I get.
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