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PIC32MX1 and PIC32MX2 are the families of microcontrollers recently introduced by Microchip. These are the cropped down members of PIC32MX3/4/5/6/7 MCUs with lesser power (40MIPS) and lower number of pins. The chips host the same M4K core but with smaller program and data memories.
This all free, open source, very small (1.5″x2.0″) and simple board is an attempt to introduce a ready to use board for easy prototyping. It has a small SOIC-28 PIC32MX1 MCU. SOIC-28 is chosen because it’s easier to solder. The breakout pins can be soldered with standard 0.1″ male/female header to be easily used with veroboard or breadboard. Diptrace source files, a schematic in PDF format and Gerbers are there to download.

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In the world of embedded systems designing, there are some main design objectives which are desired by client as well as design house. These are almost universal:

• The design meets the user requirements
• The end-product is low-cost
• Minimum time in development process
• Minimum development cost

To meet these requirements in current competitive environment, the designer must be smart enough. There are several techniques which effectively reduce time and cost of development while managing to fulfill all user requirements.

1. Lock the requirements before starting the design: carefully read-out the exact client requirements. It often happens that non-technical managers take the requirements from client and pass on to the designer. When the designer comes up with the final prototype, he comes to know that client was looking for something else, huh! This has happened to me several times. So if management doesn’t mind, try to interact with the client at the very early stage of project to get the exact picture.
2. Re-use previous designs: Try to reuse what you already have and used in other designs. You better know the pros and cons of your previous designs and try to the best options you have. This may include schematic parts, the components and layout libraries etc.
3. Use available and tested firmware components: Often firmware libraries are available for every vendor of main MCU that you are going to use. If there are no exclusive requirements otherwise, use the available code. It is tested and trusted.
4. At least initial design should be on a tested hardware:  This may be a development kit or a PCB of previous design (Keep the royalty thing in mind haan..). Now a days, demo kits are cheap, tailor-able to some extent and have some great features. If you don’t have kit(s), you can also take help from reference design of the vendor. Every vendor has ref-designs of almost all hot topic in industry. Like Zigbee is a hot field today and every vendor like TI, Atmel, Microchip etc. have their demo boards and firmware stacks to download and develop upon.

There may be other things besides mentioned above, what is your experience?

Many embedded geeks think that what will be their future if they invest time, effort and money in PIC32 family of microcontrollers from Microchip. Will their investment be secured, for instance, those choosing ARM Cortex-M3 based MCUs like those offered from TI, NXP, ST etc. The ARM users are confident that their experience will bring fruits when they will upgrade towards Cortex-R and Cortex-A series of relatively high end processors. One thing is also being observed that after these power MCUs, one often tends to go for MPUs (application processors) rather than staying at MCUs. While MIPS M4k/14k and are designed for general purpose embedded and deep embedded applications, especially for MCUs, up above them are mostly MPU rather than MCUs.

An interesting thing to note is that Microchip has licensed MIPS M14k and M14Kc core families for their future offerings so it seems obvious that they are committed to this architecture and will bring more powerful MCUs based on it.

Anyways, here are some the vendors which offer general purpose MPUs based on MIPS processor cores.

Ingenic Semiconductor’s MIPS32 based XBurst series: From JZ4750 to JZ4770 they are offering 360MHz to 1GHz clock speeds. These chips are very power efficient with power consumption down to 0.05 mW/MHz and with performance upto 2.5 DMIPS/MHz performances; amazing! JZ series has been successfully used in many tablets including Cruz tab. Ingenic has been a very successful story for MIPS. They are offering tools for WinCE, Linux and Android.

Toshiba TX39 and TX49 Series: TX39 is MIPS32 based while TX49 is MIPS64 based product. The clock speed ranges from 200MHz to 660MHz. The products are targeted towards digital entertainment and multimedia applications.

NetLogic’s Alchemy series: The processor family is targeted towards ultra low power embedded microprocessor applications. From Au1000 to Au1380, they provide varying degree of speed vs power performance. The good thing about alchemy series is that they offer built-in MCU-like peripheral set including GPIO, 10/100 Ethernet Controllers, USB Device and Host, UARTs, IrDA Controller (SIR, MIR and FIR), AC-97 Controller, I2S Controller, SSI Controllers and LCD Controller. This chiefly brings them closer to MCU features with MPU capabilities and tool sets.

 SiS’s Android-based SoCs: SiS681 integrates a 32 bit 576 MHz microprocessor with 32KB/16KB L1 I/D- cache size, 32 bit 1.3GHz DDRIII memory subsystem up to 512MB, 266MHz 2D graphic engine, x8 NAND Flash & SD/MMC interfaces, and 10/100 Ethernet Medium Access Controller.

SiS691 is featuring Open GL ES2.0/1.0 3D graphic engine, 3DStereoscopic display engine supporting 50/60Hz Pattern Retarder type of 3D LCD panels, VP6, WebM VP8 and Multi-View Coding (MVC) video format support as part of SiS Universal Video Decoder (UVD), dual channel DDR3-1333 memory controller, MIPS-based CPU as well as 400MHz audio DSP processor.

PMC-Sierra: The processor solutions are offered with Standalone processors pin-compatible and software upgradeable from250 MHz to 1 GHz, Low standby and operating power (as low as 100 mW and 1 W, respectively), Integrated processors up to 1 GHz with standard interfaces like PCI,GigE, DDR SDRAM, EJTAG, and built-in IPSEC security, Wide support from Third-Party Development Partners. PMC-Sierra’s market is networking devices.

There are, off-course, many other options but above are the most notable. There are obviously many way-outs after PIC32 but usually MCU geeks are unaware of those. I little research tells the story that there are many “brotherly” MPU vendors of them and the expertise gained after PIC32 MCU will surely bring fruits in the future. What needs to improve is, however, the MIPS marketing strategy. They need to “highlight” their architecture like ARM does; i.e., every chip that carries ARM core inside, ARM is boldly written on it. As far as the performance of cores is concerned, MIPS is not less, if not greater, than ARM rival.

The 32 bit hobbyists? What does it mean. I mean to say the near future generation of hobbyists which will do minor tasks like blinking an LED or displaying some text on LCD on 32 bit microcontrollers. But why 32 bit when there are hell lot of 8 bit and 16 bit MCUs out there? Because 32 bitters will be so common and cheap that every “”micro-aware” guy will choose only these buddies. They are now very power efficient, come with many peripherals and easy to solder “hobbyist friendly” pin packages.

So what are the options?

Many vendors have “jumped into” the band wagon of 32. Everybody is there with there own “unique” offering. However, by features and capabilities they are almost the same.

Vendors like TI, NXP, ST, Atmel are providing solutions with ARM Cortex-M3 based MCUs with Atmel has another option of it AVR32 offering. AVR32 business has not been very successful till date. However the Cortex-M3/4 has just shaken up the MCU industry and it is seen everywhere. Especially, TI’s Stellaris (formly LuminaryMicro) is very impressive.

Microchip came up with a unique solution called PIC32 based on MIPS M4k. Well, MIPS is an old guy but completely unheard in MCU market. It’s great architecture, well penetrated in deep embedded and high end markets like data server, networking devices with established 32 bit AND 64 base. However, Microchip did several smart moves to “encash” its 8 an d16 bit “base” into 32 bit. They kept the same style of coding, same IDE, and same concept of hobbyist friendly MCU with packages down to DIP-28. 32 bitter in DIP-28, amazing! Here is a small comparison of PIC32 and Stellaris series.

However, there are some other vendors with a some difference. Yes, I am talking about Freescale’s ColdFire.

To summarize, there are many other vendors with great 32 bit offerings. Why buy an 8-bitter when almost in the same price, more powerful, easy to solder (as well) and well supported option is there.

So, welcome 32-bitters!

A simple program in C# to send/receive data to PC serial port.

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I had coded CCS PICC IDE for sometime. It’s good IDE and very powerful compiler. Only “drawback” is the money you need to pay for the said tools. Attached is simple serial port routine in PICC.

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Every young boy or girl enters into a technology college or university with some dream, some hope and some inspirations. Some get inspired by their parents or relatives, some from teachers, some of them by the life style and nature of work and some, like me, get impressed by sci-fi movies.

Most of the students think that when they will get out of college/university, they will get good job with high salary, a great career is awaiting for them. This is half true. Though engineers get good jobs and earn well, it needs quite a struggle to get. The get status and get recognized but some time is required for that.

It is very difficult to get a good job right away. Though some very brilliant student get offered, most of the mediocre like me need to search around. So the advice here is that: “Accept what you find”. Start from somewhere and try to learn in the field rather than wasting time for a great job. Use the experience gained as your plus point and mention every bit of it your resume while keep trying for a better job. There is no harm in searching a better job better it is also not a smart thinking  to waste a possible opportunity to get experienced.

During my PCB design experience of around seven years, I have learnt some very simple tips to better PCB design irrespective of the EDA tool used. Here are these:

1. Use existing libraries as much as possible. Why re-invent the wheel, it saves lots of time and helps to market product quickly. Search around and you will find libraries like those hosted on this website.
2. When you design your component library, keep the pin layout as per datasheet. Often the component pin-out arrangement is difference in schematic then the real physical layout. Try to design components according to the real layout. Why? Because when you place components around that component, say an IC, you can easily copy that arrangement in your PCB layout. His will help you to better components placement hence better PCB.
3. Arrange your designed library for good reference. By this you will quickly located the parts and hence re-use the library for your future designs.
4. Arrange components on PCB as in your schematic. What components are near, to say an MCU, keep them close in layout as well. Components like coupling capacitors need to be near the ICs, they are meant to be near. This will reduce the physical length of the traces on PCB. This will also help you to understand where different parts of a “system” are located and help while troubleshooting. In-fact placing components in the PCB layout is the key to PCB design. This is the “soul” of PCB design skill.
5. Use hand-routing as much as possible. CADs are not more intelligent than human mind. Unless it is very difficult, like multi-layer PCB with dozens of ICs, use hand-routing. It will be a much cleaner and neat design at the end.
6. Keep housing of final product in mind when designing layout. Often we design PCB when no housing is decided. But at the end of the day they need to be housed. So keep mounting holes there, and better choose some readily available and simple housing and design around that. It is possible that later-on the same housing gets approved and the re-designing is avoided.

You may be interested to further read: PCB designing, science and art.

The circuit is used in many AC current sensing applications. Basically current is sensed with a 10A current transformer (called CT) and it’s signal is rectified through precision rectifier. The output is DC voltage which is then fed into MCU ADC.

This circuit, along-with voltage sensing circuit, can be used to measure power. For example it may be a part of intelligent power socket which measures the power running through an attached load. The intelligent power socket can shut down (turn off itself) on pre-programmed power outage or current threshold. The power socket may also inform a remote unit about the power status, periodically or upon request.

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The power supply change-over circuit is used where both Mains supply as well as power from rechargeable battery cells are used. The circuit, in normal mode, lets the power to be supplied from Mains to the circuit. When there is no input power, it switches on the supply from battery cells. When the input power resumes, it again cuts down the supply from battery cells and resume charging. Very simple but useful circuit.

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