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
Wednesday, December 16, 2009
PIC16F84 based Hexapod Robot
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
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.
Tuesday, December 15, 2009
AVR Shark Tag Project
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
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.
Energy Efficient AMD Processors Reach Retail
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
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.