Tag Archives: PCB

Wayne Yamaguchi talks home-made PCBs

My buddy Wayne Yamaguchi sent a little update on making printed circuit boards (PCBs) at home. Wayne always was the expert on toner transfer PCBs. This is where you print your Gerber art on a special film. Then you use an iron or a hot roller to transfer the printer toner from the plastic film to the copper-clad PCB material. The printer toner becomes the resist that keeps the acid away from the copper foil. Wayne has also figured out how to use a sponge to rub the ferric chloride on the board, so the copper etches away in seconds, not minutes.

I gave this a brief mention in an article about prototyping years ago. Wayne just keeps on improving this process and I hope to give a complete update soon. Wayne is also the guy that figured out PCB-Pool in Ireland was doing good work, as well as the USA triumvirate, Proto Express in Silicon Valley, Advanced Circuits in Colorado, and Sunstone (PCB123) in Oregon. Lately Wayne has been a fan of OSH Park up in Oregon. They operate like a community, where they take a bunch of PCB orders and panalize them on one substrate, so you can share the cost with a bunch of other people. For Wayne’s small boards, this can be ideal.

wayne-yamaguchi_blinkie-led-flasher

Wayne Yamaguchi holding a PCB he had made by OSH Park. Before stage this he makes his prototypes with toner transfer and acid etch.

So here is Wayne’s latest missive:

“Many of you know I still make my own PCBs at home. I think I just tweaked or ironed out a nagging issue. Sometimes I would lose some toner during the process of putting it on the PCB. Using the GBC laminator I’ve had reasonable success and I finally think that putting the board through once is insufficient to apply pressure across the whole board. I put the board in offset 30 degrees and then a second pass with the board turned offset -30 degrees. Putting the board through the laminator at different angles ensures all of the board gets heated and pressed.

“Here’s a board I made a week ago and now it’s aged and somewhat tarnished. You can see the test patterns in the circuit and one test pattern outside of the circuit board. All test patterns came out. The test pattern has an 8 mil trace, 6 mil trace, 4 mil trace and a 2 mil trace. Of course they all get flattened out during the process, but, the 2mil really had little toner and was surprised how well it came out even if it was flattened.

Wayne-Yamaguchi_home-made-PCB

Wayne Yamaguchi gets down to 2-mil traces with home-made PCBs done with toner transfer and ferric chloride acid etch.

“Rough measurements show the 2mil came out around 3mil and the 4 mil squished out to around 5.5mil and the 8 came out around 11 mil. Typically for prototypes I try and stay with 10mil trace widths.

“This particular prototype yielded some good info and with that info I’ve made a few changes and have sent out for real 2 sided PCB at OSHPark. The OSHPark order came out to a total $4.95. The boards were placed on a panel within a day or so and have been sent out to the fab shop. I might get the boards next week some time.

“The process is a slight derivation from Pulsar, who created this process a long time ago.  Frank at Pulsar is the originator and should get all the credit for the process.”

Well thanks Wayne, many of us still like to whip out a single-piece prototype before going to fab and this is a great way to do it. My only warning, gleaned from personal experience, is to not put any vias under surface mount parts. There are no plated-through holes with these home-made PCBs, so you have to solder a little wire into every via.

Arduboy is an uber-mini game console



A Maker by the name of Kevin has created an uber-mini handheld game console using Atmel’s ATmega328p microcontroller (MCU).

As HackADay’s Brian Benchoff notes, the Arduboy build utilizes a number of unique design techniques.

“The inspiration for this project began when [Kevin] dropped an SMD resistor into a drill hole on a PCB. This resistor fell right through the hole, giving him the idea creating a PCB with milled cutouts made to fit SMD components,” Benchoff explained.

“With a little experimentation, [Kevin] found he could fit a TQFP32 ATmega328p MCU in the Arduino – in a custom square cutout. [Additional] components – including a CR2016 battery and OLED display- use the same trick. The rest of the design involved taking Adafruit and Sparkfun breakout boards, modifying the individual circuits until something broke.”

Kevin’s unconventional PCB design approach ultimately resulted in a handheld game console that measures only 1.6 millimeters thick – and boasts capacitive touch sensors for controls.

So what’s next for the Arduboy? Well, Kevin says he wants to release the design files and source code under a fully open source license and launch a crowd sourcing campaign.

“I also would like to sell [Arduboy] kits on my site and on Tindie,” Kevin wrote on the project’s page.

“[Plus], I would like to design the board with four layers and place the circuit traces entirely on the board interior. This would allow for test points to be placed in standard ISCP and FTDI configuration, eliminating the need for an otherwise custom bed-of-nails programming interface.”

Interested in learning more about the Arduboy? You can check out the project’s official site here.

Istvan Novak on power integrity

A couple years ago my pal Bob Thomas over at Apple told me how Istvan Novak over at Sun Microsystems figured out a clever way to keep RF from radiating out the edge of the board. For years, engineers have put power and ground planes or two ground planes on the top and bottom of the board, so it makes an enclosure, a metal can that keeps the signal traces inside from radiating. Those same engineers noticed that when the edges of the boards were open, RF would leak out of the edges and cause problems with signal integrity, power integrity and EMC (electromagnetic compatibility).

Istvan-Novak_DesignCon-2014

Istvan Novak, here at the DesignCon show in 2014, figured out you should stitch resistors or RCs around the edge of a PCB so the RF would die when it hits it’s characteristic impedance.

So these same engineers would stitch hundreds of vias between the top and bottom ground planes, all around the edge of the PCB (printed circuit board). If they had a top-side power plane instead of two ground planes, they would stitch hundreds of decoupling caps all around the edge of the board.

Istvan figured out a problem with this scheme. See, if you have a via or a decoupling cap at the edge of the board, that looks like a dead short. Remember that RF reflects off a dead short. So what would happen is that the RF radiating out of the signal traces would hit the vias and then bounce back inside the board and wreak even more havoc with signal integrity.

Istvan figured out that you don’t want to just stitch vias, you want to figure out the characteristic impedance of the two planes, which you can think of as a big fat transmission line. Then you stitch resistors all around the edge of the board. When the RF hits the resistors, it dies with no reflections, since it just hit its characteristic impedance. If you have a power and ground plane, you leave the decoupling caps, but add a resistor in series to each cap. That way there is no dc power loss from all the resistors. Istvan patented this at Sun, but he insists he is not the sole person to see this. He mentioned several people that have also worked on this problem.

All this bouncing RF also raises hell with your power integrity. See, Bob Thomas described the RF radiating out of the board edge. When I mentioned Istvan’s trick to Howard Johnson, the famous signal integrity consultant, he said that what was going on is that the power planes were resonating and the resistors were adding damping. OK, but I knew my pal Bob is no slouch, and what he described seemed to be right.

howard-johnson

Howard Johnson, shown here in repose at his Signal Hill Ranch in Washington State sees the RC stitching as stopping power plane oscillation.

Bob-Thomas_Cisco_Apple_HP

Bob Thomas, a pal from my HP consulting days back in the 90s, was at Cisco when he told me Istvan’s trick.

Accordingly I arranged to meet with Istvan at the DesignCon show here in Silicon Valley. He was part of a panel discussion run by my old pal Martin Rowe, over at EDN and EETimes. So after the panel I put Istvan on the spot. Who was right, my brilliant pal Bob Thomas, who says it was killing leaking RF, or brilliant consultant Howard Johnson, who said it stopped the planes from oscillating?

Istvan smiled and said “They are both right!” He explained that if RF is pumping out the edge of the board or hitting a dead short and bouncing back inside, well then the planes are oscillating, they are intimately related. I really love this signal integrity stuff, or in this case, power integrity. Istvan also pointed out that these days you need so many power planes, you don’t get one big plane you can stitch all around the edge. For this he says you bring the power and ground planes close together, and close means like a 1-mil (0.001 inch) spacing. That raises the capacitance up and makes the transmission line formed by the plans lossy, which keeps them from oscillating and radiating RF.

Best of all, Istvan was nice enough to write me a follow up note:

“To get the basics about terminating planes, you can specifically look at “Reducing Simultaneous Switching Noise on Power Planes by Dissipative Edge Termination,” EPEP’98, October 25-27, 1998. I just realize that there is no link any more from my webpage to this paper, but you can get from this direct link:

http://www.electrical-integrity.com/Paper_download_files/EPEP98_DET.pdf

“As I mentioned during our brief chat, this paper and the subsequent patents, were not the first on the subject. One earlier paper is referenced in my EPEP98 conference paper as:

“G. Lei, R. Techentin, B. Gilbert, “Power distribution noise suppression using transmission line termination techniques,” Proceedings of the 5th Topical Meeting on the Electrical Performance of Electrical Packaging, October 28-30, 1996, pp. 100-102.”

“If you Google the plane termination subject, you will find other papers and other patents as well. One other thing worth mentioning: like every new solution, these inventions have their optimum time when they are needed and it makes sense to use them.

“The plane termination technique was very useful in the late 90s and early 2000s when many boards had large contiguous power and ground planes, prone to strong resonances. However, as system density continues to grow, we are now forced to chop up the power plane layers into many smaller puddles. Under these circumstances using edge termination becomes less attractive. If resonances are still making problems, a better way of using very thin laminates. See for instance:

http://www.electrical-integrity.com/Paper_download_files/DC02_HP-TF2.pdf

So thanks to Istvan, and Bob Thomas and Howard Johnson for making our power integrity more solid and reliable. I have a video about this as PCB202, and will back link to that as soon as it is posted.

ezLCD GPU and Arduino Uno on a single PCB

EarthMake has debuted the arLCD (Version 2.0) at Atmel’s official CES 2014 booth (MP25958). EarthMake founder Randy Schafer describes the $89 device as a smart 3.5″ color touchscreen LCD Arduino combo board that brings easy-to-program, smartphone-like user interfaces to the Maker Community.

“Release 2.0 is endorsed by Arduino by being part of the Arduino At Heart program,” Schafer explained. “It also includes firmware enhancements that free up shield pins, adds a second hardware serial port and [offers] an in-circuit programmer, freeing up 512 bytes of sketch memory.”

According to Schafer, the platform will allow Makers to more easily design products equipped with a smartphone-like graphical interface. Indeed, with the arLCD Arduino Library and the Arduino Shield I/O, DIY Makers can create 3D printer controllers, robot interfaces, home automation controllers, wireless sensors and even kinetic art.

“With over 300 I/O shields compatible with the arLCD covering every wireless, I/O, and protocol standard embedded systems, development is like building with blocks,” said Schafer. “Macros and GUI widgets allow users to build a user interface prototype fast – within hours, not days.”

Key arLCD tech specs include a 3.5 inch, 320 x 240 resolution, 65K colors, 250 nit brightness LCD with integrated resistive touchscreen. Additional features? A 16-bit GPU, 4 megabytes of flash memory and USB 2.0. The arLCD – which operates from 6 to 9 volts – draws less than 200mA and provides a -20 to 60°C operating temperature range.

“This is a full featured, ‘smart’ ezLCD GPU with the Arduino Uno (ATmega328) on the same PCB,” said Richard Obermeyer, Vice President of Engineering at EarthMake.

“The arLCD flash drive give users the ability to simply copy fonts and bitmaps to the arLCD from a PC via USB, [while] the Arduino IDE [facilitates] rapid product development with Windows, Linux and OSX operating systems.”

AVR ATtiny10 runs LED blinker for 6 months

Check out our new AVR site. In celebration, I want to tell you about a neat project. My buddy Wayne Yamaguchi had a whole bunch of tiny coin cells left over from a project. So he whipped up a little AVR blinker using an AVR ATtiny10. The one he gave me flashes every two seconds and is quite bright. Wayne’s design intent was to put this inside a phosphor-coated globe and have a UV LED charge up the phosphors every few seconds. For this round he is just using a white LED, but you can see “UV” on the silkscreen. Wayne has done some quick calculations and it looks like if you slow it down to one 3mA flash every 8 seconds it should last for 6 months. Wayne’s trick it to take the AVR out of active mode and put it to sleep, and use the Watch Dog Timer to wake it up, flash the LED and then go back to sleep. Wayne describes the ATtiny10 project here.

ATtiny10-blinker_Yamaguchi_finger

This flasher works 6 months off a CR1220 lithium cell. Using the ATtiny watchdog timer is the secret to such miniscule power consumption.

It’s interesting to note that Wayne started out with a MCU from an Atmel competitor and found it unsuitable. As many other friends have noted about these other MCUs, Wayne said, “…a lot more coding had to be done to get the job accomplished.” He also ran into limitations where he had to do a work-around in the competitor’s chip. Another friend has commented that competing MCUs can often do one thing well, but when it needs to do two tasks, even simple ones, there are real headaches. That is why they love AVR chips. AVRs were “invented” as a complete modern architecture. Once you know one chip, it’s easy to move around to others in the AVR family, even the AVR 32-bit chips.

The only reason Wayne did not start with the AVR is that he thought he could not keep his obsolete Studio 4 install, which he knows and trusts, and still program the ATtiny10. I asked around, and my Atmel pals told me that everything Wayne would need is in the Atmel Software Framework (ASF). Sure enough that lead Wayne to a solution, and he had his ATtiny10s working under Studio 4. I kept telling Wayne to just upgrade to Studio 6, which will let you program AVR-32 and our ARM-based MCUs as well as all the 8-bit AVRs. Wayne did not want to risk changing environments, since he has several existing products that he changes and customizes and supports with Studio 4. My friends say the answer there is to just run virtual computers with VM Ware or Virtual Box. You can have Studio 4 on one Windows install and Studio 6 on another. Or you can set restore points and go back and forth between the two Studios on one install.

ATtiny10-blinker_Yamaguchi_prototype

Wayne Yamaguchi uses toner-transfer and a homemade acid bath to make prototypes in an hour.

Another interesting thing in Wayne’s blog linked above is a picture he has of the prototype. At first blush it looks like he used a router like a LPKF machine to do the board. But if you look closely, you can see some un-etched copper at the edges. Wayne uses toner transfer and a ferric chloride tank to make his own PCBs in a couple hours. The reason they look like routed boards is that Wayne is smart enough to generate the Gerbers this way so that he uses the minimum amount of ferric chloride to etch the copper. Why etch off big areas if you don’ have to? He outlines this technique in an article about prototyping I wrote a few years ago.

Now wayne did the prototype raw-copper PCB in a day to get started, but he wanted a nicer board for development (see pics and below). For this he turned to OSH Park up in Oregon. He panalized the boards as you can see from the break-away tabs on the edge. The bottom line is each PCB ended up costing him a dollar. I think he was out 20 bucks for the order and got 18 boards. OSH Park collects orders for small lots and puts them all onto a 18×24 panel used in the PCB fab industry. I like the looks of the boards since you get a silkscreen and soldermask. Don’t think, “Its just a prototype, I don’t need a silk or soldermask.” It’s you the one soldering on the board and a silkscreen tells you what goes where. It’s you re-soldering stuff and hand-soldering stuff and the soldermask is a blessing, especially with tiny parts. You want your prototype to be as close to production as possible. OSH Park panelizes two-layer boards every other day and gets a four-layer panel together every four days. You might wait a bit, but I have heard of several happy customers. For small boards like the Blinkie, they make great sense. For anything more serious I will stick with Proto-Express, right here in Silicon Valley. They do 4-mil spacing, can do 24oz copper (not at the same time!) and once your board is perfect, they have a partner in China to do high-volume for cheap. Three standard 2-layer boards in 4 days for about $90 and three 4-layer boards for $150 or so. And that is silk both sides if I remember right.

In addition to the info on his blog post linked above, Wayne sent me an email with the information about the flasher. He uses Evernote to store his notes as he does a project, so below are his notes to himself. I put in current Digi-Key pricing.

Wayne-Yamaguchi_Blinkie-LED-flasher

Wayne Yamaguchi shows the Blinkie flasher he designed.

Wayne did this project a couple months ago. What was interesting was how much longer the flasher ran compared to his calculations. We are not sure if this is because the batteries really have more energy when you discharge them this way, or maybe there is some other factor we don’t understand. It’s good news nevertheless. I can tell you the flasher he gave me a couple months ago is still flashing every 2 seconds. Here are Wayne’s notes:

CR2016, CR2032 Battery Info UV Blinker

2016 – 90mAH

2032 – 240mAH

Compute the average current if LED is pulsed 1 sec every 10 minutes.

1 minute = 60 seconds, 10 minutes = 600 seconds.

1 out of 600.  0.17% duty cycle.

If the LED current is 10mA then average is 17uA.

Attiny10 Power down supply current @3V is 4.5uA.

Attiny10 pricing (Sept 17, 2013):

All prices are in US dollars.
Digi-Key Part Number ATTINY10-TSHRCT-ND Price Break Unit Price Extended Price
Quantity Available Digi-Key Stock: 21,464

1

0.69

0.69

Can ship immediately

25

0.576

14.4

Manufacturer Atmel

100

0.464

46.4

1,000

0.4256

425.6

Manufacturer Part Number ATTINY10-TSHR
Description IC MCU 8BIT 1KB FLASH SOT23
Lead Free Status / RoHS Status Lead free / RoHS Compliant

CR1220 battery Energizer Specifications.  Typical Capacity 40mA/Hr.  down to 2V.

$0.90 each at Digi-Key (Panasonic)

The Nichia 310 in the open bag measure 3mA @3V.

Watch Dog Timer table (from ATtiny10 full datasheet):

ATtiny10_WDT_prescale

CR1220 UV Blinker Board as rendered by OSH Park.

Yamaguchi_CR1220_PCB

Here is the PCB layout for the CR1220 battery Blinkie

 Using 3mA for LED current and 40mA/hr battery capacity gives these run-times:

Delay

tiny10current

average LED current

Estimated Run Time

1 sec

4.5uA

30uA

1,159hrs – 48.3days (~1.61 mos)

2 sec

4.5uA

15uA

2,051hrs – 85.47days (~2.84 mos)

4 sec

4.5uA

7.5uA

3,333hrs – 139 days (~4.62 mos)

8 sec

4.5uA

3.75uA

4,848hrs – 202 days  (~6 mos)

0.25 sec

4.5uA

120uA

240hrs – 10.04 days

0.125 sec

4.5uA

240uA

163.6hrs – 6.82 days

64mS

4.5uA

480uA

82hrs – 3.4 days

CR2016 (20mm lithium) UV Blinker Board as rendered by OSH Park.

Yamaguchi_CR2016_PCB

Here is a PCB layout for the Blinkie using the larger CR2016 battery.

Note to self: It appears that the ISPmk2 (in-circuit programmer) does program at 3V or other voltages.  The error message during programming is verification failed.  But, it appears to be programmed correct.

As a side note, future blinkies should have the LED driven from the free pin PB2.

Run-time test: 64ms sec Blinkie.  1220 battery.

6/22/2013 2.975v

6/26/2013 – 2.750V 6:16   (Should have ended today)

6/27/2013 – 2.736V 10:08am

6/28/2013 – 2.728V 2:06pm

7/3/2013 – 2.43V 9:57am

7/4/2013 – no LED.  Could be still running, but, LED is not visible.

Wayne-Yamaguchi_Francis-Lau_Blinkie-LED-flasher

Wayne Yamaguchi (L) explains the LED flasher held by crack protégé Francis Lau. Lunch was at the Pho Kim restaurant in San Jose.

ATtiny10-blinker_Yamaguchi_flash

It took a few tries, but I finally caught the Blinkie flashing when I snapped the picture.

-30-

ATmega256RFR2 powers low-cost Ethernet to wireless gateways: Part 2

Yesterday, Bits & Pieces introduced Atmel’s low-cost gateway (LCGW) reference design, powered by the versatile ATmega256RFR2 and WIZnet W5200. We explored the basics of the platform, including operation and CPU functions. And today we will be taking a closer look at the W5200 chip, memory, power system and antennae.

w5200diagram

As noted in part one of this series, the W5200 chip can best be described as a hardwired TCP/IP embedded Ethernet controller that enables easier internet connection for embedded systems using Serial Peripheral Interface (SPI). W5200 is probably best suited for those users who require Internet connectivity for applications that use a single chip to implement TCP/IP stack, 10/100 Ethernet MAC and PHY.

Indeed, the W5200 is composed of a fully hardwired market-proven TCP/IP stack and an integrated Ethernet MAC and PHY. Hardwired TCP/IP stack supports TCP, UDP, IPv4, ICMP, ARP, IGMP and PPPoE – which has been proven in various applications for many years. W5200 employs a 32KB internal buffer as its data communication memory. By using W5200, users can implement the Ethernet application they need by using a simple socket program instead of handling a complex Ethernet Controller.

On the memory side, the LCGW is designed with two external memory devices onboard. More specifically, the Atmel AT24MAC402 2-Kbit TWI EEPROM is intended for persistent storage of EUI-48 or EUI-64 addresses. This device can be used to store MAC addresses, credentials, calibration data, manifests and security keys.

The AT24MAC EEPROM also has a hardwired address of 0x0, while the LCGW includes an Atmel AT45DB642 4-Mbit SPI flash memory for in-the-field upgrades, web-site storage, logs, electronic data sheets (TEDS) or general purpose scratch pad. Although these two memory devices are useful for gateway and data concentrator applications, they are optional and can be omitted to further reduce BOM cost.

In terms of power, DC power is derived from a USB Dedicated Charging Port (DCP) inlet.

“The LCGW can be powered from common mobile-device chargers or USB ports on Wi-Fi access points or PCs using a USB Micro-B cable. For safety, the power bus is protected by an SMT fuse and ESD/EMI suppression circuitry,” an Atmel engineering rep told Bits & Pieces. “USB supplies 5VDC, while a linear buck-regulator supplies the 3.3VDC rail for the CMOS devices. Connector J5 exposes the 5VDC and 3.3VDC rails for testing. The Power-Good indicator, D1, will light if both 5VDC and 3.3VDC are present. Additional low-voltage rails are regulated and filtered by the Ethernet sub-system.”

The engineering rep also noted that the the RF front end of the LCGW antenna is designed for low-cost and high efficiency.

“That is why a PCB dipole antenna was chosen – because it does not require an external balun or specialized RF components which add cost. Plus, the relatively large area of this dipole design significantly increases the effective area and antenna aperture,” the engineering rep continued. “Larger antenna aperture dramatically improves receiver efficiency, sensitivity and range. This dipole antenna offers performance superior to chip antennas for receiving weak signals from remote nodes in marginal conditions. This antenna design is on par with high-performance external monopole antennas at a fraction of the cost.”

In addition, the antenna radiation pattern of the LCGW is moderately directional. This can be used to advantage by adjusting the orientation to bring in weak signals. Conversely, conductive objects and obstructions can be placed in the null zones to reduce adverse effects. It should be emphasized, though, that the un-populated PCB area around the antenna is essential to sustain a strong electric field, which radiates from both sides of the PCB, top and bottom. As such, it is important to avoid placing conductors, labels or stickers in this area.

Interested in learning more about Atmel’s low-cost gateway reference design? Be sure to check back tomorrow for part three of our in-depth look at the ATmega256RFR2-powered LCGW.

One Atmel ATtiny13A drives seven-segment LED displays

As the folks at Hack A Day recently noted, there really is nothing like the classic (and comforting) red glow of a red seven segment display.

And that is probably why a Maker by the name of “Five Volts” wanted to get his hands on a few ancient segmented displays. Unfortunately, controlling even one took up way too many microcontroller pins. The solution? Use a shift register.

“The principle is to control the display with four wires: vcc, ground, shift in clock [and] data in. To get a simple module, I developed a tiny PCB to plug in the LED display and at the back of it the shift register with current limitation resistors,” Five Volts wrote in a blog post.

“The challenge is to fit all these components on such small area, and to get these modules stackable. Then, it allows building a one to N seven segments display.”

Essentially, Five Volts uses a single ATtiny13 to control a total of six 7-segment displays.

“Each display is mounted on a hand-etched board, with a shift register and a handful of resistors soldered to the back,” Hack A Day’s Brian Benchoff explained.

“By having the microcontroller shift bits down the line, [Volts] created an extremely easy to interface 6-digit segment display – and the entire device can [even] be expanded.”

Interested in learning more? Both the board files and schematics are available here.

Designing a board management controller with Atmel’s SAM D20 MCU

A board management controller (BMC) is a platform that monitors the physical state of an enclosure or system using physical sensors.  The sensors track a number of critical variables including humidity, temperature, power-supply voltage, fan speed, communications parameters and operating system functions.

Unsurprisingly, a BMC typically operates independently of the main system (out of band). Key design considerations of a board management controller include connectivity; multiple serial interfaces to communicate with various sensors and administrative terminal; low-power operation in low power mode to protect against system as well power outages; and continuous operation during system outages for uninterrupted system management. atmelboardcontrollersamd20

A number of Atmel hardware components can be used to design a board management controller, including the SAM D20 ARM Cortex-M0+ (ARM) based MCU, the SHA204 Authentication IC (for security), 30TS temperature sensor and AT24/AT25 Serial EEPROM.

“The SAM D20 offers versatile connectivity options, low-power operation and a high level of integration to reduce BOM cost. Indeed, there are 6 SERCOM modules, each configurable as USART, I2C or SPI for sensors and terminal communication, thereby facilitating smaller packages and easier PCB layout,” Atmel engineer Bob Martin told Bits & Pieces. “Meanwhile, integrated 12-bit 300ksps ADC with gain stage removes the need for external components to monitor local battery voltage, as low-power operation ensures protection against system/power outages.”

Martin also noted that Atmel’s SAM D20 ensures high reliability even under system outages, with the platform featuring integrated 32-bit Cyclic Redundancy Check (CRC) of Flash, EEPROM emulation, as well as SRAM and integrated memory BIST (MBIST) to execute production testing of internal memories.

On the software side, the SAM D20 offers users access to an expansive array of tools and comprehensive ecosystem including Atmel Studio 6 (free IDE with compiler), Atmel’s Software Framework (ASF) with free SW libraries of production-ready source code. There is also the Atmel Gallery and the SAMD20 Xplained Pro Kit which boasts a built-in programmer and debugger with connectors for expansion wings.

Additional information about Atmel’s SAMD 20 MCU can be found here.

Up close and personal with Protostack’s ATmega32 Development Kit

Protostack has introduced a development kit for Atmel’s ATmega32 MCU. The kit – which measures 5″ x 3.7″ (127 x 93.98mm) – is made of 1.6mm FR4 and boasts clean routed edges.

As expected, Protostack’s ATmega32 dev kit conforms to the full size protostack form factor, allowing it to be stacked with other full size and half size protostack boards. The silicon also includes a 40 pin AVR development board, ATmega32A-PU microcontroller and power supply components.

Recently, the folks at TronixStuff had a chance to review the kit and came away with a positive impression overall.

“As you can see from the images below, there’s plenty of prototyping space and power/GND rails. The [packaged] parts allow you to add a power supply, polyfuse, smoothing capacitors for the power, programmer socket, external 16 MHz crystal, a DC socket, IC socket, a lonely LED and the ATmega32A (which is a lower-power version of the ATmega32),” the TronixStuff crew explained.

“You can download the user guide from the product page, which details the board layout, schematic and so on. When soldering the parts in, just start with the smallest-profile parts first and work your way up. There’s a few clever design points, such as power regulator – there’s four holes so you can use both ‘in-GND-output’ and ‘GND-output-input’ types.”

In addition, says TronixStuff, the layout of the prototyping areas resemble that of a solderless breadboard with the power/GND rails snaking all around – so transferring projects won’t be difficult at all. Plus, if you need to connect the AVcc to Vcc, the components and board space are included for a low-pass filter.

“It’s a solid kit, the PCB is solid as a rock, and it worked. However it could really have used some spacers or small rubber feet to keep the board off the bench. Otherwise the kit is excellent, and offers a great prototyping area to work with your projects,” TronixStuff concluded.

Interested? The ATMEGA32A Development Kit can be purchased here on ProtoStack for $23.