Regular readers may know that I am working on a high resolution video board "Evita" which will enhance even the modest of 8 bit microcontrollers. This is only one small part of the overall project plan - ultimately a series of educational and fun, open source products aimed at teaching and learning.
This is a project done in collaboration with Open Energy Monitor. The plan is to explore smarter ways to utilise very modest amounts of energy to run basic digital infrastructure - such as laptop or tablet, wireless router etc. This might be in countries where the grid is either not available - or intermittent, or on a remote camping trip where conventional power is just not present. It could be used for small scale solar energy systems, micro hydro or any number of battery power control applications.
I am putting together some building blocks for the "Open Inverter" project - which is an attempt to build a simple, low cost open-source low wattage, micro solar inverter. The project explores the interface between power electronics and microprocessor/firmware control. In addition to functioning as an inverter, the aim is also to produce boost converter, buck converter, battery chargers and dc motor drive designs - all using the same kit of parts.
50x50 PCB Format
In order to allow rapid and low cost design developments, I have also devised a new compact pcb format - based on a standard 50mm x 50mm board size. This board incorporates the Arduino style pin headers, plus another couple of connectors to increase its versatility.
The first project for the 50x50 board format was the H-bridge pcb - based on a common H-bridge driver IC and standard TO220 sized N- type mosfets. This board is now being tested - and starting to show promising signs of life, having been tried first this week as a speed controler for a 100W dc motor.
The Open Inverter will also require a microcontroller board - and the first of the planned boards is an 8-bit AVR board based on the ATmega1284P. Combined with a choice of wireless modules (ESP8266, RFM69) and a microSD card - this is a powerful monitoring and control board.
The '1284 board is the first of a planned series of small microcontroller projects - all based on the 50x50 pcb format. Others in the pipeline are the STM32Fxxx range of ARM Cortex processors from ST Microelectronics. I have 50x50 compatible designs for M3, M4 and M7 processors - it's just a matter of getting on and laying them out.
The 1284 is an 8 bit 20MHz part. The oters mentioned are all 32bit - with clock frequencies between 72MHz and 216MHz - which offers a wide scope of performance.
The 50x50 board format is small, neat and cheap to build. Additionally - there's only so much that you can put on a 50 mm square pcb - so a design is often completed within a weekend.
The Cambridge SEM Project
A good friend in the Open Hardware community has recently acquired a Scanning Electron Microscope - by Cambridge Instruments - about 1985 vintage. The basics are all working, so the plan is to produce an add-on video capture and record system - allowing videos to be digitised and stored - hopefully using open source hardware. This will be a major undertaking involving fast video data acquisition, frame stores and a lot of software.
It will not happen all at once, but I have already started looking at video acquisition and fast ADCs, plus the Evita video display board. The plan is again to use the 5050 format pcbs and make the system modular. The project is an excuse - should I need one, to play with a SEM - and also learn a bit about fast data acquisition.
NAND to Tetris (N2T)
This is a very comprehensive course that teaches the basics of building a modern computer system from the ground up. Through a series of self contained study modules - the student learns the heirarchy of digital logic and software systems. For some time I have thought that this course could benefit from having some accompanying hardware - so that the systems can be but for real - so I am currently looking at how FPGA programming in VHDL, verilog can be taught concurrently with the NAND to Tetris course - so the student can build a real computing platform.
This is related to the N2T course above. About 30 years ago, Niklaus Wirth, the creator of Pascal devised a new computing platform, operating system and compiler tools for a language he called Oberon. The platform can now be implemented cheaply (<$100) in an FPGA and could provide an ideal basis for the studying the N2T course above. Moreover, Niklaus Wirth has devised a new FPGA hardware design language called Lola-2 - to run on the Oberon platform. So we are getting close to the point where an open source workstation can be used to create new FPGA designs.
It is hoped that N2T and Project Oberon may be combined in some form to provide a much needed new means of teaching technology to students.
Magnus Karlsson of Saanlima Electronics has just annouced a new FPGA board Pepino - aimed specifically at Project Oberon and instrumentation - such as logic analysers.
I have just ordered one of the Pepino boards with a Spartan 6 LX25 FPGA and 2Mbyte of fast SRAM - watch this space.
Open Source Tools and Equipment
The electronic engineer relies on certain instruments and design tools for his or her everyday work.
For example in the electronics lab, a multimeter (DVM), oscilloscope and logic analyser are often needed. What if these otherwise comple pieces of equipment could be easily created from low cost FPGA or ARM technology, possibly using a $50 7" tablet to display the results. With a modern internet connected tablet, data could be stored in the cloud for further processing or distribution. An experiment done in the lab on one continent could be shared instantaneously with others around the world, with Skype, YouTube and Periscope we have the means to distribute valuable learning experiences to anyone who can access the internet.
Here's the Pepino FPGA board being used as a logic analyser
At the same time as encouraging learning skills by building real hardware, there are equal opportunities for computer science students to create open source software tools which would be invaluable for engineering design. Tools such as 2D and 3D CAD packages, 3D printer file converters, Printed circuit layout tools, circuit simulators and IDE packages for programming the latest chips with code..
I the last 10 years, since Arduino was first created as a teaching aid, we have made great strives with ever increasingly complex systems. We need to find new ways of training and educating people so that they can get the most out of rapidly evolving digital systems, creating a new generation of coders, makers, hackers and engineers.
I can't expect to do everything on this list myself, that is why I am involved with some extremely smart, capable people - experts in their own fields. Hardware, software, firmware, making - the list is wide and varied of the individual skills needed to make great things happen.
If you have read anything above and you would like to know more - or have something along similar lines you may wish to contribute - please feel free to leave a comment, or contact me via email or @monsonite on Twitter or Ken Boak on FB.