Any microcontroller in the ATmegaXX8 family should work, though if you`re going to go to the trouble of building this, spending a few tens of cents on extra flash memory seems like a prudent idea. A DIP socket is, strictly speaking, optional, but not having it is a genuinely bad idea. (Update: a 28-pin DIP socket is a bit of an oddball size. If
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you don`t have one handy, you can substitute a 20-pin socket plus an 8-pin socket. ) The 20pF caps are for loading the crystal. The cheap dipped ceramic kind work fine. You might be able to get away with 22pF if that`s what you have on hand (but make sure they match!). If you pick a different crystal speed, check the specs to find the right loading capacitor value. The crystal can be 12, 15, 16 or 20MHz. (Make sure you get one with at least five significant digits, e. g. 12. 000. ) You might also be able to substitute a three-pin crystal oscillator for the crystal and loading caps. The Zener diodes are there to clamp the USB D+ and D- voltages to 3. 6V (rather than the native 5V) when the AVR is driving the data lines. Most modern USB hosts deal with 5V on the data lines just fine, but some older ones do not. Not just any 3. 6V Zener diode will do; the high-current ones switch too slowly and distort the USB waveform too much. Get the 1N5227B rated for 20mA Zener current. The pushbutton switch is for reset. It`s totally optional, but convenient. Use any junk-box normally-open switch you like. (I salvaged mine from a broken stereo receiver. ) The breakaway header should fit the kind of jumper you see on computer motherboards and hard disks. The jumper is there to let you select if the bootloader or application runs when power is first applied. You could use an SPST toggle switch instead if you like. The least expensive...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
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The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
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In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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