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Hi guys,
I have been working on this project for several months and would like your input.
I've written a program driving an AD9851 chip using an Atmega328P uC.
I wrote it to traverse a predetermined frequency range using a rotary encoder. The user has a 5-position selection switch to choose his desired speed in advancing/retarding.
It was kind of tricky because very little useful documentation existed online at the time of my research.
Anyway, I would like your feed back regarding the importance of frequency control on our metal detectors. For instance, advancing the frequency on my SD2100 from it's stock setting unleashes a different animal. In short, the sensitivity increases but at the cost of ground balancing.
I originally experimented with analog switches but they were very cumbersome. The frequency selection of these switches was very narrow. Even though I found some important frequencies determining the best sensitivity/noise ratios given certain hunting grounds, I still did not have the control I'm now able to achieve.
I know other metal detectors use PLL chips like the venerable TLC555. With these other units, have people found any interesting changes in the frequency to increase function? -White's surfmaster comes to mind.
I ask because other models will not benefit from this Mod. In other words, I know some models tune their coils to specific frequencies so changing the operating frequencies will render them useless. VLF units are designed this way?
How important is frequency control? (All comments are appreciated!)
I will release a full schematic and hex if there's enough interest.
Here's a link to my video
Note: I recently ported my code from the Atmega128 testing board shown on the video. The 328P has enough pins to drive my switches/data pins and lcd. However, I'm debating weather to use the Atmega1284P instead. Even though both are available in DIP, the 1284P has more pins (28 pins Vs 40). I'm pin constrained with the 328P, so the 1284P is future proof in case I introduce new features.
Thank you guys
I have been working on this project for several months and would like your input.
I've written a program driving an AD9851 chip using an Atmega328P uC.
I wrote it to traverse a predetermined frequency range using a rotary encoder. The user has a 5-position selection switch to choose his desired speed in advancing/retarding.
It was kind of tricky because very little useful documentation existed online at the time of my research.
Anyway, I would like your feed back regarding the importance of frequency control on our metal detectors. For instance, advancing the frequency on my SD2100 from it's stock setting unleashes a different animal. In short, the sensitivity increases but at the cost of ground balancing.
I originally experimented with analog switches but they were very cumbersome. The frequency selection of these switches was very narrow. Even though I found some important frequencies determining the best sensitivity/noise ratios given certain hunting grounds, I still did not have the control I'm now able to achieve.
I know other metal detectors use PLL chips like the venerable TLC555. With these other units, have people found any interesting changes in the frequency to increase function? -White's surfmaster comes to mind.
I ask because other models will not benefit from this Mod. In other words, I know some models tune their coils to specific frequencies so changing the operating frequencies will render them useless. VLF units are designed this way?
How important is frequency control? (All comments are appreciated!)
I will release a full schematic and hex if there's enough interest.
Here's a link to my video
Note: I recently ported my code from the Atmega128 testing board shown on the video. The 328P has enough pins to drive my switches/data pins and lcd. However, I'm debating weather to use the Atmega1284P instead. Even though both are available in DIP, the 1284P has more pins (28 pins Vs 40). I'm pin constrained with the 328P, so the 1284P is future proof in case I introduce new features.
Thank you guys