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Hi Moodz
Would you be willing to share the source code also..? Reason I am asking is because I have provided extra pin functionality and may wish to use these in the future.
Cheers
I will but just noticed some other housekeeping edits to do. I just need to get a round 2it I only have square ones.
Paul I tried reprogramming the existing 250F by hitting the program button and switching the detector on at the same time and having the detector running then hitting program and all I get is Target Device Not found (Could Not detect Target Voltage VDD) I have tried to PM you but it does not seem to be getting through to you can I give you a ring for instruction.
Paul I tried reprogramming the existing 250F by hitting the program button and switching the detector on at the same time and having the detector running then hitting program and all I get is Target Device Not found (Could Not detect Target Voltage VDD) I have tried to PM you but it does not seem to be getting through to you can I give you a ring for instruction.
Regards, Ian.
Hi Ian .. I program it as follows ...
1. Turn detector ON ( no coil )
2. Connect programmer ( I use Pickit 3 )
3. Program
4. Remove programmer
5. Turn detector off
Paul I tried reprogramming the existing 250F by hitting the program button and switching the detector on at the same time and having the detector running then hitting program and all I get is Target Device Not found (Could Not detect Target Voltage VDD) I have tried to PM you but it does not seem to be getting through to you can I give you a ring for instruction.
I really like the sound, it's very nice. How can I modify the output filter for 64 or 16 Ohm? since most headphones have 32 ohms in each speaker (64 in series or 16 connected in parallel) tnx
I really like the sound, it's very nice. How can I modify the output filter for 64 or 16 Ohm? since most headphones have 32 ohms in each speaker (64 in series or 16 connected in parallel) tnx
UPDATE, I increased the TX time to the full 15us and the warbling has significantly reduced, sensitivity to small nuggets after tuning out ground is better now.
I will need to re-do those graphs.
Tony
I had a detector that warbled alot and another that was rock solid .... even though both had exactly the same components. After about a week of changing components in and out etc ... it turns out that there was stray capacitive coupling from the TX circuit to the linear 7805 regulator. The fix was simply soldering the tab of the 7805 to the shielding ground. This feedback was causing slight variation of the regulated 5 volts hence causing a warble as it would have been modulating the TX current.
This feedback also caused burst oscillation in the TX mosfet on turnoff .... also solved. The heatsink was orginally bolted ... hmm
Change R11 and R16 to 5.6 mH neosid or similiar inductors.
Change c9 and c16 to 10uF electrolytic.
Change R13 to 100k
Change R14 to 100k
Change C4 to 1uF
Change C5 to 1uF
Result = supersmooth audio tone :-)
Easily drives a 4 ohm speaker to 250 mW at full volume ( ... approx ) with V1.2 firmware
moodz
Hi Moodz,
I am just ordering the parts and there seems to be a lack of stock of the INA125UA chips, tried Digikey, Mouser and Element14 but nothing..?
Would you know where I could purchase these from stock..?
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