In the process of working on a robot project, I needed to draw up an Arduino hole pattern and outline in CAD as part of the design. I figured others could use a similar drawing — after some polishing up, I had this Arduino hole dimension drawing (PDF).
Arduino hole dimension drawing – [Link]
Dave builds this intriguing agriculture robot. Are a swarm of robots like this the future of farming? [via]
Prospero is the working prototype of an Autonomous Micro Planter (AMP) that uses a combination of swarm and game theory and is the first of four steps. It is meant to be deployed as a group or “swarm”. The other three steps involve autonomous robots that tend the crops, harvest them, and finally one robot that can plant, tend, and harvest–autonomously transitioning from one phase to another.
Prospero, a Robotic Farmer – [Link]
The objective of the project is to create a low-cost, tropicalized, and rugged sensor that is capable of testing the impurities in water. [via]
Water Purity Measurement Using Polysensor – [Link]
You might find yourself needing a low power H bridge for driving a motor like I once did. The 555 IC can drive a load up to 200mA, source or sink, which might make is usable as a driver, if one can control the output as desired.
555 / 556 H bridge – [Link]
A certain knock at the door may tell you if the person behind it is the one expected or just somebody else. Each knock on the door itself cannot tell you too much, it can be lighter or stronger and that’s all about it, there’s no information on pitch here. But a certain sequence of knocks can be an actual secret code. The secret knock is encoded in the actual timings of the knocks, the time between each knock creating a distinguished pattern.
Secret knock detector with 555 – [Link]
One of the applications of 555 timers is a class D amplifier. In its most simplistic form it can be built with a single 555 and the 200mA current capability is enough to drive a small speaker, making it a good replacement for a low power amplifier. But I wanted more; I wanted to use it to build an amplifier that had enough power to allow listening to music in a small room. Adding a high power stage to a classical 555 class D amplifier was too easy, so I decided to build my own high power 555.
555 class D amplifier - [Link]