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I wonder there are so many things to learn for an embedded systems developer. This field is rapidly changing. What to learn to keep oneself up to date? Generally this industry is segmented into two portions. One the people who which design advanced DLD systems. These usually work on FPGA based SoC designing. Their tools and skills may include learning an IDE like that of Xilinx. The other guys usually used MCUs and microprocessors (like me). They write the firmware for these device and (usually) design the PCB as well. My focus is on the second type of people as this relates to me better.

Here are the things which I think, are necessary to learn:

1. Hands on experience of at least two MCU families. One on the higher end and the other on the lower end. The higher end may be the ARM architecture. The low-end party should be the one which has tiny-miny MCUs like PIC or 8051 or may be AVR. There are times when you don’t need to use the horse power of ARM, so you need a small companion for that.
2. Good PCB design tool like Diptrace (please forgive if you don’t like it). The Altium designer is a complete design suit not just for a single developer but for a whole team to system design, PCB design, software development and mechanical assembly in a single unified tool. Some people still are in love with older tools like OrCAD. I just prefer Diptrace over OrCAD.
3. At least 2 good RTOSs
4. Embedded Linux. Well, you at least need to have know-how of Embedded MPUs like Cortex-M8/9. Linux seems to me, the future and it would be norm to use Linux in most of the designs.

The LM3S811 Breakout board is design with the same spirit of PIC32MX1 Breakout Board to make easy to get started. Stellaris is the microcontroller family initially designed by Luminary Micro (LM). LM was acquired by TI, thanks to the recession of 2009-on-wards. It’s a very promising family. TI has included some other members into family including the floating point LM4F based series. The JTAG connector may seem “too big” but this was to keep it compatible with the actual connectors coming from TI; like this board be used along-with LM3S8962 demo kit and same kit can be used to program this board.

Download Files:

Often I have thoughts where to invest my “pocket money” and more importantly time and effort. The ARM architecture, I think, is the answer. Currently a kit of TI’s LM3S8962 Stellaris series (which was LuminaryMicro when I had bought this demo kit, ahh I can’t forget LuminaryMicro, recession has some unforgettable memories in my mind) rests in front of me and, as always, am “admiring its beauty”. So “why” is the question:

• ARM is well penetrated and it will stay in market for a long time (at least a decade, I think).
• The development tools are everywhere easily available and those are cheap. So you can get started easily.
• Well supported architecture among IC vendors, in-fact, it has become a “fashion” to launch MCU based on Cortex-M3. Look at TI, NXP, ST, EnergyMicro etc. etc… They are “running” hard to catch it.
• ARM is well heard among tech managers so it will increase an engineer’s market value. Somehow I realized that if I want to stay in this field (embedded systems), then I will need to maintain my market value. Otherwise somebody else is always there ready to replace me with lower pay.
• All other advantage which something “in” may have.

So I have decided to “target” this dimension more intensely in the coming times.

3-axis accelerometer

It’s a very simple design based on ADXL335 accelerometer chip from Analog Devices. The PCB has only one layer. The header output is provided for power input and X, Y and Z axis analog voltage representation of respective acceleration. A PDF schematic is also there if somebody is not a Diptrace fan .

Download Files:

I have been designing PCBs for around 8 years now. My first experience was with OrCAD 9.x. OrCAD is very powerful tool and widely used in electronics industry. However, somehow, I was a little tired of it as it seemed to me based on old technology. Working in the schematic capture section was not very easy and layout was even difficult. Components library creation could easily lead me to head scratching.

It was some 3 years back. I was really looking for a software which is easy and just does the job. One day I found Diptrace. I learned it very quickly as it was very easy. The user interface was very intuitive and seems to be a really modern interface built-in “this era”. The PCB layout was also very easy, nothing less nothing extra, just every necessary tools available there. The component and footprint library creation was also very easy. Most importantly the cost of software was affordable. It increased my efficiency and reduced the headache of PCB design.

Diptrace has very good import/export options. One of the great option is Route-> Electra/Specctra Interface-> Export Autoroute DSN and Import Autoroute SES. I use this option for complex designs to export my unrouted board to Specctra, which is a great autoroute tool, route in it and import back the SES file into Diptrace for fine tuning. This is one of the great features of Diptrace I really missed in Eagle.

There are, however, a few things which I wish could be improved.

• First is to improve the 3D viewer section. The graphics rendering should be improved to make it look more closer to the real PCB.
• Diptrace currently does not support built-in 3D object creation, which I think, can be a big bonus.
• The third and last is the back annotation. There come times when we need to design the layout first and schematic later. In this case Diptrace is not going to help you much.

All in all, Diptrace is a very good tool for beginners as well as experienced engineers. It saves times, makes PCB design an enjoyable experience and does the job which you expect from a professional designer.

“This industry is all about change. Those that facilitate change will win. Those that resist will suffer”.

Some days ago I was reading an online article. It was about 8-bit microcontroller market, probably some new series launch by a vendor. Above phrase was basically a comment which I loved so much that I decide to write a post about it. It touched my heart, basically!

Embedded systems is all about change. every now and then a new ASIC, microcontroller family, software, development kit etc. is added. A developer like me always wonders what to do and what to leave. There are so many things to do and an engineer’s resources are so small. Time is also an issue and managing time these days is difficult. But one thing is clear, this is the era of “change or die”. If you will change, you will live; if not, you are a dumb; and “dumb one will always die”.

There are some many fields within Embedded Systems, like MCUs, FPGAs, RF, HF, Control systems, Smart Energy, Power Electronics and bla bla with variety of tools to learn. As the time passes by, the need to change oneself rapidly also increases. Well, it’s a tough field, the Embedded Systems. But we have no option but to update ourselves, have we?

Often a complete embedded design is split into smaller modules for more flexibility. In this way, the system can be upgraded only by upgrading one of its required part. The best practice is to split the design into two major parts:

1. Base board or the carrier board or an expansion board
2. Processor board or plugin module

The base board if often designed with maximum peripherals and IO options to be used in future applications. The common peripherals like Ethernet, USB, RS485; storage like flash, microSD and other options are populated. A common connector interface through headers is provided where the Processor board seats. Here is an example of such a system. A good base board for simple automation and control applications may contain:

1. Ethernet
2. USB
3. Serial such as RS232/485
4. microSD slot
5. Flash memory with an interface like SPI
6. Stereo input/output
7. On-board temperature sensor
8. Power supply unit
9. Joystick
10. A display like LCD, OLED or TFT
11. Clock/calendar chip on I2C bus
12. Some relays
13. Digital and/or analog outputs
14. Output power for IOs like sensors

The processor board, as the name describes, carries the main CPU like a microcontroller and is the brain of the system. The designer can change the processor board as the requirement changes.

The major disadvantage of this kind of scheme  is the production cost as an application may carry un-necessary on-board components. This approach is, though, great for small production, prototyping and for a range of products which shares similar features. For example an industrial controller with variety of options in different versions can be offered to customers. It is easier to maintain for small companies and can relatively easily be modified.

The other idea, which is very different from above one, is to use a back-plane like those used in PLC. The idea is use a common serial bus and connect/attach all the system modules on the very bus. The system modules may include power supply unit, main CPU unit, IO unit, communication module and several others as per requirement. In this way the user can control his cost by selecting appropriate set of modules. This also frees the manufacturer from repetitive system revision, rather the vendor only upgrades, or provide better option than the existing one.