Wednesday, December 16, 2009

PIC16F84 based Hexapod Robot

PIC16F84 based Hexapod Robot
This Hexapod Robot created by Mike Smyth. It uses 12 R/C servos for actuators. The 6 that raise and lower the legs are Hobbico CS-72 1/4 scale and the 6 that move the legs forward and backward are several brands of standard 1/10 scale servos (all are similar the Futaba S3003). The total robot weight is a little over 5lbs and the payload capacity is around 5lbs additional. The vertical travel of the legs is 1 7/8". Overall length and width is 13" X 11". When crouching, it's 5.5" tall. When standing up there is 3.5" of ground clearance under the body.


There are actually two PIC16F84's on the hexapod. The main processor contains all of the walking code and generates positioning pulses for all 12 servos. Twelve of the 13 I/O lines are used for switch inputs - one on the bottom of each foot and a contact sensor in the front of each leg. The servo pulses are output sequentially on the last I/O line. All the second processor does is de-multiplex the pulses from the main processor and send them to the appropriate servo

R/C Transmitter Range Tester

electronic circuit project - R/C Transmitter Range Tester
This project suitable for people who like with the transmitter system. It's an electronic analog project. You don't have to programming the IC to build it. The function of this electronic project is to measure the RF power being radiated from a transmitting antenna.

Among the Amateur Radio fraternity, a device such as the one described here would otherwise be known as a Field Strength Meter (FSM). Its main purpose would be to check that RF power is being radiated from a transmitting antenna. Some FSMs are tuneable across a wide range of frequencies, which allows the device to work with different transmitters and antennae - usually from HF to VHF and beyond. A difference with this unit is that it is only sensitive to those signals in the R/C section of the radio spectrum. The on-board trimmer allows you to tweak for maximum signal strength of your frequency of choice, whether it be 27MHz AM, or 40MHz FM.

In order to read the received signal strength, such a unit would ordinarily employ a mechanical analogue meter. The unit described here differs in that it uses four super-bright LEDs. The benefit of this is that it allows you to read the display from a distance - even in bright sunlight.

Tuesday, December 15, 2009

AVR Shark Tag Project

microcontroller project animal tag

The goal of this project was to develop a shark tag working bench-top microcontroller platform. It is to be used for on-animal, in-situ data logging applications involving sharks and potentially other large pelagic.

The project used the Atmel Mega32 microcontroller to develop the core platform and functionality of a data archival tag. The project use temperature and pressure as sensor variable. The tasks ranged from logging sensor data to developing a simple user interface that requires only the addition of a laptop and a custom RS232 serial cable in the field.

It used an off-the-shelf SD (Secure Digital) card using flash memory for large capacity multi-read/write data storage. The microcontroller’s ADCs (analog to digital converters) were used to convert analog voltages produced by select sensors into digital format.

XBOX Controller

XBOX Controller Controller
What is this? It's a system that will allow basically anything that can talk udp to control an Xbox. Why would you want to do this? I have no idea. I have my reasons, maybe you have some too. How this works: The XBOX buttons are physically pressed by arms (stiff wire) attached to servos that are controlled by a Basic Stamp 2. The BS2 is controlled by a gumstix over a serial port. The gumstix talks udp and accepts commands. So if you want to control an xbox, you basically have to talk a simple udp protocol to the gumstix.

xbc-c-controller
For this I tried 2 controllers, a PSP and a Nintendo DS. The udp protocol is simple. Build a message with the status of your controller, and the system takes care of moving the physical fingers on the xbox controller. The protocol is as follows: '!!' for start of message, and '##' for end of message. The juice of the message is a 1 character button identifier, followed by a 1 byte state. 1 means the button is pressed and 0 means button is not pressed. Here is a sample message:

The message should be self explanatory. So the controller (in this case the psp or nds) polls inputs every so often and then dumps the state. I had it all working at every 100ms, but then something happened - not sure what - so I backed it down to every 250ms. The bottle neck is on the BS2, and to keep things consistant, I just kept all polling intervals the same.

The app on the gumstix consists of 2 threads. One listens for udp commands and the other babbles out the serial port at 38.4k. The serial thread wakes up every 250 ms and sends the status of all buttons to the BS2. The status is stored in global variables that are updated by the udp thread whenever the controller sends an update.

The serial protocol to the BS2 is simple. A 'A' signifies a start of message followed by 8 bytes of status for each of the buttons currently supported. The PIC decodes this message and tells the servos to respond accordingly.
xbc-c-pic.

Sunday, December 13, 2009

PICkit 2 Starter Kit


Features:
  • Low Pin Count demo board supporting 8/14/20-pin mid range PIC microcontrollers.
  • 20-pin PIC16F690 Midrange microcontroller. Note: Requires the AC162061 ICD Header and AC164110 adapter to debug.
  • A series of 12 Lessons on assembly programming that cover I/O, A/D converters, timers, interrupts, and data tables (All source code files are provided)
  • Getting Started in PICBASIC PRO tutorial on developing and debugging in BASIC with a FREE microEngineering Labs PICBASIC PRO™ Demo Compiler (contained on the PICkit 2 CD)
  • HI-TECH PICC™ LITE C Compiler with MPLAB IDE.
MPLAB Integrated Development Environment (IDE) is a free, integrated toolset for the development of embedded applications employing Microchip's PIC and dsPIC microcontrollers. MPLAB IDE runs as a 32-bit application on MS Windows, is easy to use and includes a host of free software components for fast application development and super-charged debugging. MPLAB IDE also serves as a single, unified graphical user interface for additional Microchip and third party software and hardware development tools. Moving between tools is a snap, and upgrading from the free software simulator to hardware debug and programming tools is done in a flash because MPLAB IDE has the same user interface for all tools.

Energy Efficient AMD Processors Reach Retail


AMD announced that their new Athlon processors were built for energy efficiecy. AMD said the processors would cut the power requirements of desktop processors by over one-third, boosting the performance-per-watt process. Basically, the processors will reduce power consumption in active and idle states. We featured AMD previously for their green energy initatives, and because they are reducing the lead contained in their chips.

Now, the new AMD processors, the Athlon 64, Athlon 64 X2 and Sempron processors are currently available in several stores in Japan.

A number of stores in Japan have begun to sell energy efficient versions of AMD Athlon 64 X2 3800+ and 4200+ models, which consume 65W, down from typical 89W thermal design power (TDP).

In terms of energy consumption, laptop computers consume much less power, and they run on DC voltage — an advantage for off-grid users.

Continuous Microchips Glucose Monitoring Shows Promise


Popular Science is reporting on the work of MicroCHIPS, a Bedford, Massachusetts firm that's designing under-skin implantable devices to measure chemicals and deliver drugs. The exciting news is that the firm will be performing clinical trials next year on its glucose detecting microchip, a device that has apparently shown positive results when studied on animals.

From the company technology page:

MicroCHIPS' technology is based on proprietary reservoir arrays that are used to store and protect chemical sensors or potent drugs within the body for long periods of time. These arrays are designed for compatibility with preprogrammed microprocessors, wireless telemetry, or sensor feedback loops to provide active control. Individual device reservoirs can be opened on demand or on a predetermined schedule to precisely control drug release or sensor activation.

Our reservoir-based platform can also be used in passive control systems without microprocessors or power sources. MicroCHIPS' passive systems are designed to release or expose their contents based on the controlled degradation of polymeric matrices over time. These systems form the basis for miniature insertable devices that provide maximum flexibility for device placement.

Samsung ships 8GB microchips

Memory is getting smaller and smaller by the month. Samsung has announced shipment of 8GB microcards that can be used in portable devices such as cellphones and even in external memory adapters for a huge boost in storage. The day will come when traditional portable HDs will be phased out in favor of the more versatile flash drives which you can use anywhere - since there are no moving parts.