Ultra Low Power Microcontroller With A Supercapacitor

This post is a follow-up to this blogs FRAM (ferroelectric random-access memory) post in June, and takes a look at a recently-introduced Texas Instruments (TI) FRAM LaunchPad development platform, as well as how to use FRAM effectively in a particular use case.

TI MSP-EXP430FR5969

First the FRAM development platform. It appears from a post on 43oh.com that the MSP430 ULP (ultra low power) FRAM board, MSP-EXP430FR5969, was soft-launched in February 2014, then rolled out with more fanfare and distributor partners in June 2014, per the Australian post, "element14 offers ultra-low power with Texas Instruments LaunchPad dev kit," and a number of other similar new product posts. The Australian post above says,

"Embedded FRAM, a non-volatile memory known for high endurance and high speed write access, together with ultra low power makes the MSP430 development platform suited for a wide variety of applications ranging from metering, wearable electronics, consumer electronics and the Internet of Things (IoT) to industrial and remote sensors, home automation and energy harvesting. The new development kit includes TIs new EnergyTrace++ technology, the worlds first debug system that enables developers to analyse power consumption down to 5nA resolution in real-time for each peripheral...Key features include MSP430 ULP FRAM technology-based 16-bit MSP430FR5969 MCU; 64KB FRAM/ 2KB SRAM; 16-Bit RISC architecture up to 8-MHz FRAM access/ 16MHz system clock speed; 5x Timer Blocks; Analogue: 16Ch 12-Bit differential ADC, 16Ch Comparator; Digital: AES256, CRC, DMA, HW MPY32; 20 pin LaunchPad standard leveraging the BoosterPack ecosystem. Various components including on-board eZ-FET emulation for programming, debugging and energy measurements have been provided in the evaluation kit for a fast start; on-board buttons and LEDs on the board enable quick integration of a simple user interface in addition to a SuperCap allowing standalone applications without an external power supply."

MSP430FR5969 LaunchPad Power Domain Block Diagram

The part that especially interests me is the SuperCap that enables a minimal level of operation without an external power supply (and without a battery?). Enabling MCUs to operate without external power sources was the topic of an earlier post on this blog, "Microcontrollers: Batteries Not Included. Or Needed." That post discussed getting the MCUs power from small energy harvesting devices. It would be nice if a supercapacitor turns out to be another no-batteries-needed option for MCUs. The boards Users Guide shows the power domain block diagram to the left and says, "The board is designed to support five different power scenarios. The board can be powered by eZ-FET or JTAG debugger, external power, BoosterPack power, or standalone super cap power." A bit of online research is needed, it appears, for me to totally understand just how much the MSP-EXP430FR5969 board can do using just the 100 mF capacitor and no external power. If Google and I cant figure that out, Ill check with Ed Smith to get my answer!

If youre interested in the MSP430FR5969 microcontroller (MCU) that powers the above development platform, consider reading the Electronics Weekly article, "Exploring FRAM microcontroller-based design – Texas Instruments." The graphic at the right from that article shows how flexible the memory configurations are in that MCU. Here are a few more resources to help you learn more about the MCU and its platform:

1. MSP430FRxx MCU overview page on TIs site.
2. MSP-EXP430FR5969 LaunchPad Evaluation Kit page on TIs site.
3. Overview of MSP430 Ultra-Low-Power MCUs PDF on TIs site.
4. MSP-EXP430FR5969 LaunchPad Development Kit Users Guide PDF on TIs site.
5. 6-part video tutorial on YouTube for the MSP-EXP430FR5969.

If you want to buy the MSP-EXP430FR5969 kit, Id suggest you consider either direct from TI ($24.00) or from Newark ($24.05). Octopart gives a good look at the price spread and availability of the kit, with costs ranging from TIs $24 up to more than $39 from Arrow. The 43oh post above shows one way manufacturers entice hardware developers to buy newly released components. For $5 extra ($29 for the kit instead of $24), when you ordered the MSP-EXP430FR5969 kit from TI when it first came out, you got both the kit and a "LS013B4DN04

SHARP Memory LCD display...1.35?...96×96 pixels wide...booster PCB has touch capability, with touch strips on either side of the LCD" which retailed for $18. I dont know if $5 for that LCD is a better deal than the small LCD Ed Smith had at the Humboldt Microcontrollers Group meeting last week, but the touch strips would have made it an interesting component with which to experiment. Element14 also has a road kit for the board which includes the same LCD.

The other part of this post was going to be on an ideal use case for the MSP430FR5969 MCUs FRAM. However, I wrote more about the TI development kit than I planned on, and Im being mindful of feedback I got that said (at least some of) my posts were too long. So for people interested in reading about that use case right away, heres a link to the article about the FRAM-MCU application I mentioned at the start of this post. Ill discuss that use case in tomorrows post, and maybe have a couple other examples of good applications for an MCU that doesnt pull much amperage and has FRAM. If you read the FRAM-MCU application article, send me your comments and questions regarding that article -- arcatabob (at) gmail {dott}com. Thanks!

**********

Read More..

Democratize Electronics From Idea To Circuit In Minutes

Squink is a recently launched Kickstarter project which is described as "the personal electronic circuit factory."

It seems like Squink could be of high interest to Humboldt people who frequently prototype new electronics designs, especially ones involving microcontrollers (MCUs). I personally wouldnt need a Squink of my own, but Id love to have access to one. If this Kickstarter campaign hits its funding target of $100,000, every makerspace and hackerspace is going to want a Squink. However, the project appears to be off to a slow start, so I hope the funding pace picks up over the next week or two.

According to the BotFactory website,

"Using inkjet technology, Squink prints conductive ink on a surface to create the traces of the circuit. You can print GERBER RS-274X files or upload PNG, JPG or BMP files...Squink uses the soldermask file generated by your CAD tool to place dots of conductive glue in every connection point where a part is to be connected...Aimed at assembling SMD based circuits, Squink uses vacuum to pick components from a tray. Then it aligns them using computer vision, rotates them according to the "Centroid and Rotation" file created in your CAD tool and places them accurately."

Squink is a simplified printed circuit board (PCB) fab and assembly prototyping tool. However, the TechCrunch post says that the Squink founders arent trying to replace the PCB batch fab companies like OSH Park, or the straightforward PCB fab companies.

"They don’t want Squink to replace the current process of sending projects to manufacturers to build but want it to be a tool for people to test out their ideas immediately, without having to create a delay in the creative process. “We really want to be a stepping stone — try it out really quickly and once you’re ready, then you crank out about 100 boards from a manufacturer..."

The BotFactory blog gives a little more background on the genesis of the Squink concept.

"We were both attending a challenging class on Bio-electronics...you had one semester to design, assemble, and test a basic EEG system (also called a brainwave reader; our version was capable of measuring attention and winking). While the design of the EEG probes on paper and then on a CAD program took a big part of the semester, what was later revealed as the most critical part was the circuit fabrication itself. Out of the 8 teams, only 1 managed to finish on time for the end of the semester. The reason was simply frustrating: it took PCB manufacturers around 7 to 10 days to fabricate and ship all the boards. If you had made even a single mistake in your design, you had to send your design for fabrication again, and you were sure to miss the deadline."

Although the implementation of the concept may seem a bit simplistic to PCB designers who are used to complicated circuits on multi-layer boards with very narrow traces, I expect people using the Squink and similar personal electronic circuit factories to come up with novel and interesting applications over the next few years. I have no doubt that enterprising middle school students who get their hands on a Squink will make money printing off custom circuits for their friends and neighbors. And those same middle school students will later develop a new printing technique, or a new electronic circuit substrate, or some other personal electronic circuit factory concept that no college student or electrical engineer has yet thought of...

What MCU circuit would you print tonight if you had a Squink to play with?

**********

Read More..