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This article shows you how to to build your own a simple ECG device & heart monitoring system. The signal from the body is being amplified, filtered to remove the noise, sampled by an Analog to Digital converter and then sent to your computer through RS232.This project use the famous instrumentation amplifiers device from Analog Devices(AD620). [via]
Heart monitoring device - [Link]
This is a really nice drum machine that utilizes DIP switches to control the drum beats. Those types of switches are hard to manipulate, but I imagine you could easily replace them with an easier to use 2 or 3 position toggle switch.
The two dip switches work in tandem so that each 1/8th note can have four possibilities (two bits) worth). If the position on the right switch is 0 and the position on the left switch is 0, then nothing is played. If the setup is 1 and 0, then a kick sample is played. If the setup is 0 and 1, then a snare sample is played. If the setup is 1 and 1, then a hi-hat sample is played. [via]
Arduino drum machine - [Link]
This is a simple design that interfaces a PIC 16F877 microcontroller to the USB bus using the FTDI FT245 USB FIFO device. It has been designed using a simple single sided PCB with only one surface mount device, the USB chip itself. All schematics, PCB layouts and software will be available for download. [via]
PIC USB interface - [Link]
This is a 24 bit I/O card designed to work with the parallel/printer port of an Amiga or PC. It uses the Intel 82C55 I/O chip to facilitate this.The device has 2 address lines, a chip select, read and write strobe. The parallel ports of the Amiga and PC have a limited (3) number of control lines, even then at different pin-outs, at least the 8 data pins line up! Remembering that the 8086 bus was multiplexed, inspired my solution, use 2 data pins with latches for the address and one control signal to control them. I then use an inverter to create /RD and /WR from another control line and the final control pin to control the chip select. [via]
Build 24 bit parallel port I/O card - [Link]
This adapter is connected to expansion bus same as joysticks adapters, giving us the possibility of connecting an standard keyboard, type AT or PS/2. (Old keyboards 94-keys are unuseful). This heart of the adapter is a microcontroller PIC 16F84. This PIC should be programmed before insertion on the board ( a few steps forward will be explained how to program it). Once the PIC be programmed an inserted, is ready for working, and you don’t need to open nor load anything in your Spectrum. [via]
IMAR-3 PC-KEYBOARD ADAPTER - [Link]
Although i linked to some DIY tutorials on printed circuit board making in the past, i decided to write my own tutorial to cover all the bits and pieces so that any beginner with no knowledge can obtain a PCB using the photo etching method. Lets start with the tools and materials i used:
DIY Printed Circuit Board Using Photo Etching Method - [Link]
The experimenter’s pot is a solid state potentiometer using Dallas semiconductors DS1869 and Nationals LM78L05 two electrolytic capacitor two small push button switch and two optional Molex connector. this project is very useful especially in finding the right value of resistor in your experiments, you can attach this circuit to your next project that uses a pot or trimmer cause there are three types of DS1869 these are:
- DS1869-10 which is 10K
- DS1869-50 a 50K version
- DS1869-100 the 100K version
The experimenter’s pot – Digital Potentiometer - [Link]
This is PIC based Programmable LED design by DrSkippy27 but the original design is Alex Weber who is Instructables meber which built a great programmable LED based on the AVR chip. This simple project is fun and it provides a great building block for playing with collective behaviors. [via]
PIC-based Programmable LED - [Link]
This is the circuit which inputs the control voltage which was created by the turning of the motor in PIC. The input voltage to PIC is converted by A/D converter. Changed voltage is used for the PWM function of the CCP to control the motor drive. At the circuit this time, a small motor is used as the generator to detect the number of rotations of the motor. The input voltage (the control voltage) to PIC is changed by the fluctuation of the number of rotations of the motor. [via]
DC motor speed controller - [Link]
It’s based on an AT90S2313 and a Dallas DS1621 Digital Thermometer. The temperature is displayed on a dual 7-segment display, and two buttons are used for setting parameters. A high current relay switches the heating element. The Dallas DS1621 chip interfaces to the 2313 using a I2C interface. This is a 2 wire bidirectional bus with a speed up to 400 kbps.Up to 8 DS1621 devices can be connected on the same I2C bus. [via]
AVR based Temperature Controller - [Link]
