I have been reading Miller & Ranum’s e-book on Python/Algorithms. (A superb book which is also free online.) While looking through their chapter on Algorithm Analysis, I took their idea of using the Python
timeit methods a bit forward to create a simple plotting scheme using
I am working on a “weather monitor” project that involves a Raspberry Pi taking to a DHT11 Humidity and Temperature sensor and serving up the collected data as a graph, over a web page. So, I wanted to first get an idea about how this sensor works.
The DHT11 is designed to work with a microcontroller, but we can coax it to send data with a simple circuit, as shown above.
I have been looking at prototyping with some ARM Cortex M4 chips, and many of them use a 48 pin LQFP packaging. Sadly, I haven’t been able to find a decent 48 LQFP to DIP adapter PCB in India. The only one I saw was expensive and designed in a crazy way (4 sets of orthogonal pins) which made it useless for breadboard prototyping. So I decide to create one of my own.
I just got the batch of ATtiny85s I ordered for some pals at a local Maker group. I have articles here on ATtiny84, but not on this chip. So here are some quick notes on getting started with the ATtiny85.
The first thing you need to program the chip is an AVR programmer. I am using a Pocket AVR Programmer from Sparkfun. But you can buy much cheaper programmers. Look for USBtiny programmers – in India you can get one of these for about Rs. 350 from ebay.in.
My friend asked me the following yesterday:
“Is it possible to make the build script at my company flash some lights when it fails?”
I gave her some suggestions which involved the usual suspects – Python and Arduino. Now it’s all up to you, I said. But soon, I started fidgeting, and I can’t help it. I need to try this myself.
I am feeling a little nostalgic. So I rebuilt one of the first circuits I put together when I started messing around with circuits in eighth grade. It’s a very simple beginner project, and might appeal to your child – real or inner!
I want a pan/tilt scheme for the camera of my Raspberry Pi based home monitor robot. But rather than use a pan/tilt bracket with two servos, I thought I could simplify things by using one servo for titling the camera and using the robot chassis swivel to pan the camera.
I am working on a Raspberry Pi based robot, and recently acquired a Dagu chassis and a Dagu Mini Driver for this project. As soon as I had the mini driver hooked up and the wheels starts turning, I felt an irresistible urge to put an ultrasonic sensor on the chassis and have it roam around by itself.
Here’s a short post on communicating with the raspberry from your phone’s browser.
Our goal is to turn an LED connected to the Pi on and off, by accessing a web page on the phone’s browser. Both the phone and the Pi are on the local WiFi network.
I wanted to design a circuit to generate a nice digital pulse (for input to a microcontroller or the Raspberry Pi) every time an LDR is quickly obscured from ambient light – like for instance, when you pass your hand over it. I didn’t want to use the popular solution of reading the analog values, and processing it on the microcontroller (averaging, finding peaks, etc.), because this will take up valuable processing time, and I want to avoid lag as much as possible, by offloading this work to hardware.
So here are 3 attempts that I made, and the results.