Here’s a demo of the MMA7455L 3-axis accelerometer in SPI mode using the Bus Pirate. The MMA7455L has:
- 2/4/8g selectable measurement range
- 10bit or 8bit output
- force and pulse detection with interrupt
- I2C and SPI interface
Get the MMA7455L breakout board for $15 at Seeed Studio
MMA7455L 3-axis accelerometer - [Link]
This project is a DIY metal hunting robot that uses a Parallax microcontroller to hunt down metal objects while avoiding bumping into objects. [via]
To avoid any collision with other objects (such as furniture), the robot uses an ultrasonic range detector (radar) as well as 2 side infrared range detectors. The radar, placed on top of the robot, searches the area infront of the moving robot for obstacles. If one is located within close proximity (30cm), the radar scans the area (rotates with the use of a motor) for any other possible paths which contain no obstacles within range. The 2 side IR range sensors make sure that if something misses the range of the radar, a side collision won’t occur.
DIY Metal Hunting Robot - [Link]
This project shows how to add an autofire button to your mouse. To achieve that “Peter Skaarup’s” used a PIC 10F200 along with a momentary push switch and a transistor. When the autofire button is pressed the microcontroller drives the transistor to short the left mouse button about 17 times per second. Check how this is done on the link below. [via]
Autofire Mouse Button – [Link]
HSETI1 PCB is a small and simple application board for Atmel AT89C2051 microprocessor. It has an 89C2051 CPU, 8 driver outputs (e.g. LEDs, relays), a speaker output, a light sensor input, 3 extra inputs, optional serial port, small simple PCB.
HSETI1 PCB: An 89C2051 CPU, 8 driver outputs – [Link]
Ben Krasnow has designed and built a joystick that contains no electronic parts — only fiberoptics. The motion is sensed via quadrature encoding, and the signal processing is handled by an arduino microcontroller. In his video he explains how this joystick works, how the transmitters sends the light, how it is encoded into axis position and how an Arduino reads this position. Watch his video.
Fiberoptic joystick with quadrature encoders and arduino - [Link]
This project shows how to interface a rotary encoder to PIC 18F1220 and an LCD. The numbers on the LCD counts up and down according to the scroll of the encoder. Check how this is done on the link below.
Interfacing rotary encoders to PIC - [Link]
TI has released the datasheets on their new MSP430G2xxx chips.
The MSP430G2x32 and MSP430G2x02 series of microcontrollers are ultra-low-power mixed signal microcontrollers with built-in 16-bit timers, and up to 16 I/O touch sense enabled pins and built-in communication capability using the universal serial communication interface. The MSP430G2x32 series have a 10-bit A/D converter.Typical applications include low-cost sensor systems that capture analog signals, convert them to digital values, and then process the data for display or for transmission to a host system.
New TI MSP430G2xxx chips on the way - [Link]
This device allows solar cell arrays to be connected to either conventional lead-acid, sealed lead-acid, or lithium storage batteries without fear of overcharging. It allows two different electrical loads to be driven from the batteries at two different charge states to maximise power usage efficiency.
Photovoltaic Solar Battery Regulator and Load Controller – [Link]