If you have ever played around with macro photography, you’ll know how hard it is to get a focused image of something that isn’t two-dimensional. For virtually every 3D object, you’ll have to deal with the depth of field – the small region where things are actually in focus. [David] came up with a neat homebrew solution for making sure everything in his macro photos is in focus using a discarded flatbed scanner and a Raspberry Pi.
[David]’s technique relies on focus stacking. Basically, [David] takes dozens of images of the same object, moving the camera closer by a fraction of an inch before snapping each frame. These pictures are stitched together with CombineZ, a piece of software used for extending the depth of field in images.
The hardware part of the build is a Raspberry Pi hooked up to a stepper motor driver and the shutter button of [David]’s camera. By attaching his camera to the carriage of a flatbed scanner, [David] can inch his camera ever closer to his object of study while grabbing the images for CombineZ.
The results are impressive, and would be nearly impossible to replicate any other way without tens of thousands of dollars in camera equipment.
[Stephen] picked up a Raspberry Pi to do a little hardware hacking and add a blinking LED to the many feathers in his software development hat. He picked up an analog to digital converter and a temperature sensor that would serve him well in a few projects he wanted to put together, including a weather station and a small Pi-controlled home brewing setup. He ended up not liking Python, and didn’t like the C-ness of wiringPi. He’s a scientist, so he’s most comfortable with R and Matlab. Of course, playing around with a R and a Raspberry Pi means replicating his sensor-reading code in R.
[Stephen] put together a neat little package that will allow him to read his sensors over an SPI bus with his Raspberry Pi. Yes, this functionality can easily be duplicated with Python, but if you’re looking to generate beautiful graphs, or just do a whole lot of statistics on something, R is the tool you need.
It’s a cool project, even if it is only measuring the temperature. Using R for the nerd cred isn’t bad, either.
If you’ve picked up one of those really cool STM32 ARM dev boards, you’ve probably poked around looking for a good toolchain. No fear, then, because [Matt] has your back. He put together a template for the ARM Cortex-M4 powered STM32 board.
[Matt] had been using a template for the STM32 F4 we’d covered before, but found the implementation a bit lacking. Wanting to exploit the functionality of his fancy STM32 F3 board, [Matt] took the F0 template whipped up by our very own [Mike S] and got it to work with the newer, fancier dev board.
There are a few bonuses to using [Matt]’s template; the ARM chip in the F3 Discovery board has a hardware floating-point unit that is inaccessible using the Code Sourcery G++: Lite Edition toolchain. [Matt]’s use of gcc-arm-embedded allows access to the hardware FPU, a great benefit for a great board.