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  • lloydsteve0 commented on GreatScottLab's instructable DIY Digital Spirit Level1 year ago
    DIY Digital Spirit Level

    Research, why ask this here?

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  • lloydsteve0 commented on bcb10's instructable ATTiny EMF Detector1 year ago
    ATTiny EMF Detector

    I don't think that is very likely. The main reason lamps fail is excessive heat. That could be the result of excess voltage but that is not really likely either. More likely is lamps that are too powerful for the fitting, or poor quality fittings. Either way, if there is insufficient ventilation the lamps will become too hot and fail prematurely.Another reason lamps fail is turning them on an off too often, the thermally induced heating and contracting of the filament causes too much stress. Maybe your mother is trying to save power by switching on when entering a room and off when leaving. A false economy in some instances. Best is to replace with LED lamps as the old ones fail.

    I think this would be better if you feed the antenna to pin 2 via a diode and use a potential divider to feed sufficient DC to the open end of the antenna to slightly forward bias the diode, and put a small capacitor across the input resistor. That way it will be more like an AM Radio detector. As it is you will have AC noise appearing at pin 2, but you are measuring a DC value randomly depending on how long it takes to measure the analog signal. (Typically 100micro seconds on a 16MHz clocked Arduino ). This means a lot of reads are with a negative value yielding zero and will not be included in the result thus affecting your average.Also I don't know what your clock frequency is on the ATTiny. If it is at 1MHz then the analogRead will take much longer. And, since that command is runni...

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    I think this would be better if you feed the antenna to pin 2 via a diode and use a potential divider to feed sufficient DC to the open end of the antenna to slightly forward bias the diode, and put a small capacitor across the input resistor. That way it will be more like an AM Radio detector. As it is you will have AC noise appearing at pin 2, but you are measuring a DC value randomly depending on how long it takes to measure the analog signal. (Typically 100micro seconds on a 16MHz clocked Arduino ). This means a lot of reads are with a negative value yielding zero and will not be included in the result thus affecting your average.Also I don't know what your clock frequency is on the ATTiny. If it is at 1MHz then the analogRead will take much longer. And, since that command is running inside loop() the other commands there will add to the cycle time between reads. You might consider setting the ADC to run freely and generate an interrupt on each conversion. You can then read the ADCH and ADCL registers (or just ADCH if you left shift the results and only require 8 bit resolution - see ADLAR bit explanation in datasheet) to get your measurement.Since the capacitor I mentioned and the input resistor form a low pass filter you can choose what frequency range is of interest to some extent but moreover you could do away with your average calculation and just directly light the LEDS according to the DC voltage on pin 2.

    Your parts list states 100 Ohm resistor but the breadboard schematic shows 100k and the actual breadboard and protoboard devices appear to have 3M9. A high value seems appropriate, but what worked for you in what situation?

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  • lloydsteve0 commented on bcb10's instructable ATTiny EMF Detector1 year ago