Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Use oscilloscope as terminal output

This is another great project that came from dutchtronix. This time oscilloscope is used as text terminal. This seems to be quite practical project. Imagine situation that you need to debug microcontroller code. The easiest way is to use terminal which is usually a computer. But computer isn’t always on your workbench. So why not to use an oscilloscope as terminal?   If you already have the Dutchtronix AVR Oscilloscope Clock, you now also have theDutchtronix AVR Oscilloscope Terminal which works on same hardware, only firmware needs to be uploaded. Terminal is capable to output 12 lines with 20 characters each. It also includes all ASCII character set, automatic scrolling, flashing cursor, multiple baud support, etc. Continue reading

Autopilot for autonomous aerial hobbyist vehicles

The idea of this project was to build DIY autopilot kit that anyone could build and use in their flying models like helicopters.   Autopilot uses two dual axis ADXL202 accelerometers to read 3D acceleration, also it reads attitude, engine stats, position, payload stats. All these readings and control is operated by realtime system OS, which reads each sensor at some predefined rate. This is really quite complex system which seems to be stil under development – but it already gives positive results. Project details are available on sourceforge project page. Continue reading

Acceleration logger with SD flash memory

Ever wandered what forces affect you on a roller coaster? Then build this Accelerometer logger which stores acceleration data to SD memory which can be analyzed later. Acceleration is read using 3-axis LIS3LV02DQ inertial sensor from ST-Microelectronics, a uALFAT from www.ghielectronics.com to manages the SD-card interface, information is displayed on HCMS2915 display. All control is done with PIC16F876 microcontroller. PCB board is mounted to plexiglass, where necessary holes for battery pack and other components are milled. Probably this is really fun thing to take to amusement park with you. Continue reading

Contact-less tachometer counts up to 99kRPM

There may be some situations when it is hard to use a tachometer only because it is impossible to read revolutions per minute mechanically. The only way is to read RPM without touching rotating shaft.   This great design was constructed by Ibrahim Kamal who used an IR signal to transmit and receive it reflected from reflective stripe fixed to rotating shaft. Device is controlled by AT89S52 microcontroller which counts reflected pulses and displays value on LCD. RPM counting algorithm uses last three times between pulses and this way constantly gives instant RPM value. RPM meter consists of two parts: microcontroller board and IR proximity sensor connected to microcontroller board via simple 4 wire cable. Project files are available for download in a single zip. Continue reading

PIC18F2550 based harmonic distortion meter

This simple device, designed by Wichit Sirichote, measures the quality of AC voltage. The device measures 3rd harmonic which is used to find the distortion value comparing to fundamental frequency.   Device calculates DFT of signal which is captured via step down isolation transformer and 10-bit ADC. Testing showed that clean sine wave gives less than 0.5% of distortion, while square wave gives about 33%. Project description includes detailed measurement theory outline and practical examples as well. Project is built on test board which was developed for general purposes. Source code is available for download. Continue reading

Interfacing RFM12 transceiver module

RFM12 is a transmitter and receiver module in single board. It can be powered by using 2.2V to 5.4. it makes ideal module for embedded systems. Module communicates via SPI interface.   Wigbert Picht and Dirk Milewski have made simple Atmega8 tesboard, where RFM12 module is soldered as SMD element and can be configured with jumpers. There can be any sensors connected to this board like temperature. Schematic and sample Bascom AVR program are available for download. Continue reading