Velleman K8062 3rd party firmware upgrade

Velleman K8062 DIY kit is one of the most successful DMX transmitters sold world-wide, but it is also one of the poorest performers. Velleman uses an antiquated slow speed USB protocol on a device that supports Full Speed USB. A community developed firmware upgrade that offers up to 80x times better performance is currently undergoing […]

7400 competition entry: Bad driver feedback display

Gagandeep built a “bad driver” feedback display. It’s a huge 40X16 LED matrix spanning ~80cm in width, and it’s designed to be placed on the rear windshield of a car. The spacing of 2cm between LEDs is enough to ensure that the driver doesn’t have an obstructed rear view. Using 2 74HC595 8bit serial in […]

7400 competition entry: Homemade 7400

Arup entered his Homemade 7400 into the Open 7400 Logic Competition. A video of it proving his concept is available below. At an earlier post I’ve said that I didn’t have 7400ICs in my drawer. Surprisingly, the local store was saying 74HC00 out of stock. Hence I decided to make my own 7400 IC. 7400 […]

Controllable aquarium moonlight strip

Theatrus build a controllable aquarium moonlight strip. Royal-blue Osram high power surface mount LEDs provide the lighting, and an ATmega88 the control. RS485 port is used for control. All of the design files should be available shortly. Its quite potent (visible with the main 6x80W T5s running). Its easy to mount (a handful of command strips […]

Simple USB DIY Li-ion battery charger circuit

arup shared his USB DIY Li-ion battery charger circuit in the project log forum. The circuit uses both op-amps of an LM358 to control the charging of a single cell lithium ion battery. Charging automatically stops when the battery is full, and it is possible to charge batteries that have gone below the undervoltage limit. Power […]

Do it yourself heart monitor

victzh posted picture of his DIY ECG using an Xprotolab mini-scope/logic analyzer in the project log forum. Some time ago I bought an excellent toy – Xprotolab mini-scope/logic analyzer by Gabriel Anzziani. I touched it signal legs, and immediately saw that it picks up 60Hz through my body. I looked around and found couple of simple and inexpensive ECG […]