Build primarily as proof of concept and because I found the challenge interresting, this little unit is able to send an ascii string terminated with a CR/LF via a RS232 connection. It`s emulating the transmission of a barcode and can be used with any kind of equipment that is expecting a barcode. I have been a little lazy on this project, as I hav
Click here to download the full size of the above Circuit.
e based it on the arduino serial V2 layout. This is also the reason I don`t have a neat schematic to show. But I have the reference schematic from the arduino board. And my handdrawn notes on the wiring and keypad. Please note that I have replaced the transistor version of the TTL to RS232 circuit with a MAX232 chip. This makes a more stable signal for the RS232 communication. Oh, and there is also a connection to pin1 on the SUB-D (not shown on the schematic) for supplying the BAR-X with a 5 volt from the RS232 port. (only available on specific equipment) And finally to make the whole thing work. Here is the sourcecode for the embedded program. Mind you it`s nothing fancy. I tried using some procedures to shorten the code. But it never worked So I took the sequential approach instead. /* * Barcode Emulator V0. 1 * * = * * A pre-defined ASCII code will be send * * using RS232 to a PC or other equipment * * connected via the serial connection. * * A Carriage Return(CR) and * * Line feed (LF) char will be appended. * * = * * Programmed by Rene Rasmussen 2011-09 * * This software released under the GPL * */ #include // define _delay_ms(). // for the delay to work correctly the compiler optimization must be set to -O2 #define UART_BAUD_RATE 9600L #define UART_BAUD_CALC(UART_BAUD_RATE, F_CPU) (F_CPU)/(UART_BAUD_RATE)*16L)-1) // wait ms Milliseconds void delay_ms(uint16_t ms) { uint16_t t; for(t=0; t<=ms; t+) _delay_ms(1); } void...
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....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
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....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
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.....
characters left: