Well, yes, that is very likely what the program is doing. However the relatively small resistance of R4 will have no effect on the net input voltage because the input impedance of the ATmega is on the order of 10Mohms.
So I return to my original answer/question: Is this for static discharge...
OKokOK You have released my inner pedant... Here's what I believe to be the schematics:
On the left is my reverse engineering of the breadboard. The diode is wrong and the relay power is also wrong. So. I would throw out that book and start over -- BTW what book is it? I hope I don't...
In #1 it may be that the parallel resistor allows some constant current to flow when the transistor is on, since the piezo is basically a capacitor. Without actually trying it I won't assert that it's unnecessary, but an experiment should show.
For #2 my opinion is that the resistor is...
Back to the some batteries run faster question...
It occurred to me that it might be the difference in voltage between, say, zinc and rechargeable (1.5 -> 1.2v).
Also as DrZoid points out, the car may be drawing more current than the battery can provide (c.f. internal resistance...) and thus...
OK, I'll give it a try...
1) AC-DC converter: The voltage rating of any power supply says how many volts it supplies, and is often qualified with the maximum amperage that can be drawn while maintaining that voltage. Most "wall-wart" type converters are not voltage regulated, so the voltage...
I'm not sure your question has been answered, so, to beat a dead horse, here's a schematic for a MOSFET output driver board using a PIC rather than an ATmega controller:
http://www.etantdonnes.com/DOC/USBPIC/doc/USBPIC_trans_schematic.png
See the right side where there are 8 (enhanced) N-channel...
You probably need a pull-up/down resistor on your switch input pin. 10-100K oughta do the trick.
If you already have that in place, then we need a lot more information about your circuit and software.
I think what you are trying to communicate is that you have existing wiring for a two switch light control, whereby a room light can be turned on and off from two locations... Here's a page with two possible schematics for such a beast...
I'm not quite sure what an "ESC" does, even after skimming over the manual. I think it may translate "hobby servo" PWM signals to speed control for larger motors. If that's the case you may only need a variable pulse width oscillator (maybe made from at 555 chip) or commercial hobby servo...
Ah, I see... Yes, you should be able to just enlarge them by the right ratio. The proof will be in the pudding when you compare the same object in multiple photos. But as I said, the relative perspective will be off for objects at different distances.
The beauty of an -- ideal -- pinhole camera is that there is none of that focal length nonsense to obscure the relationship of image to object. The ratio of I-O distances should be the same as the ratio of I-O sizes. So you should be able to move the image plane on your more-distant camera to...
You need to set the ADCON1 register to
adc.h: #define ADC_0ANA_0REF 0b00000111 // ALL DIGITAL I/O (0/0)
to shut off the analog->digital converters so you can use digital I/O.
(Actually, look ADCON1 up in the spec sheet to verify the bit settings,
I get confused by their attempt to make...
You can use your DC meter instead of an LED for the NOx long-period test. You can also use the DC setting to "look at" a higher frequency AC, especially one that swings between 0 and +V, because it will try to average the signal and thus show a lower than +V reading -- if there is any oscillator...
Also as a 555 no-oscillate test you could check the output voltage with both DC and AC settings on a multimeter to see if there is any difference. Zero AC volts and your one-click speaker would indicated that the chip is not oscillating...
The Panasonic 24C411 appears to be a piezo, which means it's mostly capacitive, so you probably don't need a limit resistor at all. But you could experiment to see how loud things get with, say, 100 ohms...