Trigger programming with its build-in pushbutton. The solution I came up with was to add a tiny USB keyboard circuit to the pen`s interface. One method to have the pushbutton trigger a programming command would have been to add a microchip to the pen`s interface and connect it to the PC using a USB to serial converter. The microcontroller could then sent some
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data to the PC every time the button is pushed. However, that would also required a script on the PC side to check whether the pen was sending data. What I wanted was a universal interface, which could be used to program any type of microcontroller, which wouldn`t require any scripts or drivers. What I came up with was to add an USB keyboard interface to the pen. In order to make the pen work no matter which command needs to be executed to program a chip, I decided it would send the arrow up keystroke followed by an enter. That way, I can just type the programming command (e. g. "make flash") once in a terminal window and pressing the programming pen`s button afterwards will make the same command execute. I did not want to increase the size of the programming adapter, so my build space was extremely limited. I found V-USB, a software USB driver for Atmel AVR chips. That website contains a lot of links to example projects, one of which is a self-calibrating ATTiny45 USB keyboard interface. The ATTiny45 is a small 8 pin chip which just fit in the space I had available on the pen`s interface. Due to the self-calibrating code, it did not require an external crystal, which is normally needed due to frequency precision requirements of the USB interface. Basically, that project was a perfect starting poattachments_refint and someone had already done most of the work for me. Excellent! The circuit I put together is shown in the...
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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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....
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