Garage Monitor Has an Extra Arduino

[Jody] wanted to know when his garage door was open. He details his setup which uses a temperature sensor read by an Arduino to send over XBee radio to a computer running a Windows Service. We have seen this twice before, and is noteworthy as a lesson. The XBee radios have the ability to read analog data, relay digital signals, and a lot more. This means the Arduino is completely unnecessary. For example, the Tweet-a-Watt uses two of an XBee’s ADCs to measure voltage and current in a Kill-a-Watt power meter. Programming an XBee is really simple, with the help of tutorials from SparkFun and Adafruit. A bit of programming and soldering should get [Jody] back his Arduino. We hope this note will help you find more creative uses of XBees without microcontrollers.

[Via Make]

Inventing robot athletes

The human body is an amazing instrument from an engineering standpoint. Replicating just one part of it proves extremely difficult but these athletic legs show a lot of promise. This is the work of a Japanese researcher named [Ryuma Niiyama]. He’s been working on the design for years, and is now using pneumatic actuators to mimic the muscles in a human leg. The lower portion of the leg uses a spring mechanism that resembles some running prosthetics currently in use. These serve as a spring to store energy and reuse it by bouncing against the ground. He’s trying to teach his robot to use these legs; taking it through a learning process necessary to use the thigh actuators for locomotion and balance. We were surprised at how life-like the motion in the video after the break is. Even when falling down the movements are very life-like.  We thought the movements of Little Dog were real enough to be creepy, and this robot may be close enough to our own mannerisms to fall into the uncanny valley.

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Make your own minimalist AVR ISP

Giving a programmer is a great way to get people started in microcontrollers so If you want a cheap simple AVR programmer this might just be what you’re looking for. It combines the V-USB firmware, USBtiny software, a few resistors, and some zener diodes. An interesting trick using this programmer is if your trying to program another 8 pin ATtiny you can use some tape to isolate the USB data pins and then piggyback the target ATtiny on the programmer.

Unfortunately in order to flash the ATtiny for your programmer you need a working programmer so it’s somewhat of a catch-22.  Make sure your careful when setting the fuse bits because it will use the reset pin making it hard to reprogram without additional programming hardware. AVRs in general are a great way to start using microcontrollers so if your interested give out tutorials a go. You’ll find some tips to get started in addition to information about using an Arduino, or a DAPA cable to flash the firmware to this chip.

My RepRap is bigger than yours

This 3D printer build is a thing of beauty. It prints in ABS plastic on quite a large base. The platform provides all of the X and Y movement, making the gantry stationary except for the Z axis. it is possible to print parts up to about 15″x15″ by 13″ high. The gray hose snaking down around the right side of the print head is a fume extractor, keeping the air clear around the PID controlled head, and heated base. Judging from the example items this prints with fantastic accuracy.

[via Make]

AVR HV Rescue Shield 2

[Jeff Keyzer] has a new version of the HV Rescue Shield available. This tool allows you to use an Arduino to reset the fuse bits on AVR microcontrollers. This is necessary if you make a mistake and disable the reset pin, or choose the incorrect clock settings (this will probably happen to you at some point). In order to bring the chip back to life you’ll need to use High Voltage Programming. The last version of the shield only worked with High Voltage Parallel Programming (HVPP) but this rendition can also use High Voltage Serial Programming (HVSP) for 8-pin chips that don’t have enough inputs for parallel communications.

As we talked about in our AVR Programming Tutorials this is no replacement for a high-end programmer like the STK500 or an AVR Dragon, but if you already have an Arduino a kit will only cost you $20 (or you can etch and build it yourself). We would have liked to see a breakout header for the HVP signals for off-board use. The absence of a breakout header doesn’t preclude this, but since you need the on board boost converter for the 12V signals, and because this shield can’t be used with a breadboard due to pin spacing, it’s hard to patch into signals for non-DIP use. We also think some clever firmware hacking and this could be used for HV programming, like we needed for that LED light bulb.