Today I write about a new project I have been thinking about the last few days. I call it "Raspberry Pi Embedded Lab Bench"!
Now the reasons why I want to build this are many, but the biggest is that I don't have any space in my apartment for a "real" lab bench/table and because of this I hardly ever work with any of my projects, but this project will change that!
My line of thinking is that if I gather the basic parts needed for a "lab bench" in one place, including the computer, and make everything in a small size and easily movable, it will be mentally easier for me to continue working on projects than it is now when I must gather the instruments I need and when I'm done I have to put them back in the storage. For me at least this is a mental obstacle that I have to get over before I start do any serious work.
Anyway, lets talk about the more interesting part of this project, the hardware.
The heart in this project is of course a Raspberry Pi 3 (rPi3). The reason I choose the Raspberry Pi 3 SBC is mainly because I have one collecting dust and that the SPI and I2C interface are functioning out of the box, another reason that I found a articel on Adafruits blog how you can program ARM microcontrollers directly with the rPi3 without using a third party programmer. (See this post on Adafruit how to use OpenOCD on the rPi3: https://learn.adafruit.com/programming-microcontrollers-using-openocd-on-raspberry-pi/overview).
The image below shows the rPi3, power brick and two Buck DC/DC converter that will power this "Lab Bench".
Everything will be powered by the old laptop charger brick (19 V, 3 A). I will use two cheap Buck DC/DC Modules, one to deliver 5V @ 4A to the rPi3 and the other one is a variable DC/DC that will be used as a "Lab PSU". The rPi3 have a 3.3V output on the pin header as a bonus.
The output voltage for the "Lab PSU" is controlled with a 50k potentiometer, in a later revision of the project I will use a digital potentiometer to control the voltage directly from the rPi. I will also measure the current with a module called INA219 (https://www.adafruit.com/product/904).
All this will be attached to a MDF or a similar board together with one or two breadboards, I also have to break out the SPI/I2C and UART pins from the rPi3 header so they are easy to find and use.
That's about it! Thanks for reading and if you have any questions or suggestions feel free to comment below.
Happy tinkering!
