Category Archives: project logs

Handheld 2.4 GHz Spectrum analyzer

Here is a 2.4GHz spectrum analyzer Miguel built into a Nokia 3410 case. His design is based on the CYWM6935 2.4 GHz radio module. It’s controlled by the ATMega8 microcontroller. This project scans the 2.4 GHz range and displays the bands currently used on an LCD. The really cool thing about this project is that […]

PSOC3 custom board development

We wrote about Kmmankad effort to build a custom PSOC3 development board. After the initial design, he consulted Cypress engineers about his board. They advised him how-to improve his design. Here are the latest revisions: Added additional vias between the top and bottom layers to improve return paths. Crystal routing improved(Capacitors on same side,traces shorter). […]

Current sensing with the Arduino

Luca made an Amp-meter using the ACS712 current sensor, and the Arduino. The ACS712 is a fully integrated, hall effect based, linear current sensor. It converts the current that passes through its input pins to a proportional voltage on an output pin. He connected the output pin to an analog pin of his Arduino, and […]

Clock source for the EasyDriver

Henrik designed and built an adjustable clock source for the EasyDriver that maintains the same motor speed over a range of step resolutions. It adjusts the driving frequency depending on the resolution of steps the EasyDriver makes per input pulse. EasyDriver is a stepper motor driver that moves the motor one preselected step for every […]

I2C controlled 4X4 RGB LED matrix

Mashiara designed an I2C controlled 4×4 RGB LED matrix. He uses 3 PCA9635 I2C-to-PWM drivers with 16 PWM outputs. Each IC controls a different basic color of the LEDs. The up-side to this design is that all of the drivers are on-board, and only control signals are needed to manipulate the matrix. The down side […]

DIY ultrasonic range finder

Zipppys123 is building a DIY ultrasonic range finder based on this design. Once it’s externally triggered a PIC12C508 is used to generate generate the ultrasonic pulse, and measure its echo. The ultrasonic pulse is amplified using a MAX232 TTL-to-RS-232 level converter, while the echo is amplified and demodulated using two op-amps and comparators. Via the […]

Switch AC appliances remotely with cellular control

Ezflyr built an AC relay switch that receives commands over the cellular phone network. An ADH8066 quad-band GSM cellular module handles the communication, while a PIC18F2550 controls the relays and reads temperature sensors. The goal of this project is to remotely switch heaters on his aircraft, which requires a few hours of preheating before a […]

Near field communication TRF7970A breakout board

Benjamin wanted to use the Bus Pirate with various near field communication protocols, so he designed this breakout board for the TRF7970A NFC chip. It has a 13.56Mhz on-board antenna, and a optional SMA antenna connector. Other devices can also interface with this board, all the IO pins of the IC are brought to a […]

Open source soldering iron driver update

Arhi has been busy debugging noise from PTC type soldering iron sensors. The problem was the sensor’s sensitivity to the current used as a bias. If the current used is greater or less then 1mA the sensor picks up too much noise. In the latest revision of the Soldering iron driver both PTC and TC […]

Wireless home energy monitor

Here is a project that allows you to keep track of your household power consumption over a wireless connection. Jone’s energy monitor project counts electricity meter‘s indicator pulses, which the electrical distribution company uses to bill you. Once it reads 5 minutes worth of consumption data, it is broadcast to a web server over a […]

nedoCPU-32: Breakout board for PIC32s in DIP packages

Shaos is making a breakout board for PIC32 microcontrollers in DIP through hole packages. He based his design on his previous project the nedoCPU-16, a breakout for the PIC16F870 uCs. There is a 3.3v power supply onboard along with all the bypass capacitors required for the PIC32 to function properly. As an added feature he […]

Reflow soldering toaster oven

Frank wrote an instructable about a solder reflow oven made from a toaster: As I get more serious into my electronics hobby, I need to work with more SMD components. Some component packages are very difficult or impossible to solder with a traditional soldering iron. To solve this problem, I decided to hack a toaster […]

High precision decade frequency generator

Jbeale designed a high precision decade frequency generator based on a 26Mhz ovenized oscillator with stability of +-1 part-per-billion, or +-0.0000001%. The generator is controlled with a PIC16f1823 microcontroller, which provides interface and frequency division. Firmware, PCB and schematic are uploaded on his site. He also provided a link to Tom V.B. impressive site that […]

Through-hole development board for 18-pin PIC microcontrollers

Raj made an all through-hole development board for 8bit PIC microcontrollers. Feature list is quite impressive: An ICSP header to connect PIC16F1847 to PICkit3 On-board voltage regulator (+5 V) A HD44780 based character LCD display 8 LEDs to read the status of output pins 6 Tact switches for providing inputs A potentiometer for providing analog […]