Author Archives: R-B

Elecrow launches Crowbits: Electronic Blocks for STEM Education

With the grand success of CROWPI2, an all-in-one portable Raspberry Pi Laptop development platform, Elecrow has now come up with Crowbits: easy-to-use electronic building blocks for young inventors. Crowbits include more than 80 modules that can be easily snapped through built-in magnets to create projects. It also incorporates a graphical programming software -Letsocde, where users can simply drag and drop blocks to develop applications.

Crowbits: easy-to-use electronic building blocks for young inventors

Meet CrowPi2: An all-in-one portable Raspberry Pi laptop for STEAM learning and rapid prototyping

When it comes to STEAM (Science, technology, engineering, art and math) education, the Raspberry Pi is perhaps the most affordable, powerful, and versatile learning tool for all ages and skill levels. The versatility of this little computer comes from its incredible interconnectivity feature that offers direct connection of sensors and electromechanical components, thereby allowing the users to learn embedded hardware and programming in a very simple and engaging way. Since it first came out in 2012, the Raspberry Pi has been the most adventurous tool of teachers in the classroom to foster learning, awareness of computer programming, and extend the computer capabilities to multiple domains of education. The best way to learn Raspberry Pi is by doing projects. There are tons of starter kits available in the market for Raspberry Pi to satisfy both the programming and hardware needs. Elecrow’s has just announced a kickstarter campaign for their latest CrowPi2, which is an unique development platform combining the power of the Raspberry Pi computer with a bunch of sensors, displays, and software applications in a form of portable laptop suitable for easy learning and rapid prototyping.

CrowPi2: An all-in-one laptop and prototyping device based on Raspberry Pi

For more details on the introduction pricing and onboard features of CrowPi2, visit the Kickstarter page.

Acme traffic light restoration

The Southern California Transportation Museum is one of the largest private transportation museums in the United States. We are privileged to have among our artifacts a set of Acme traffic lights. This type of traffic signal was deployed in the Los Angeles area in the 1920s and 1930s. This was the time when every city was experimenting with different types of traffic signals. Later the Automobile Club convinced everyone to adopt the three-light signal they use today. During the brief time they were in use, the ACME traffic light became the favorite of the Hollywood cartoonist so, that’s why you see them all over the movies. It’s the one with the arm and lights. The arms were used during the day since lights used electricity and electricity cost money. Then, at night the lights were used because, logically, you couldn’t see the arm.

The museum has one of the original ACME signal controllers – but it has a fatal design flaw, it thinks that it’s running a traffic signal. That means it will run it all day and night, wearing out the motors. So, the museum decided to replace the old controller with a new one consisting of a Raspberry Pi and a 16-channel relay module. The relay module was chosen because in the past it had provided reliable service in the museum’s signal garden. Also, because it is incredibly easy to program.

Acme controller

Acme traffic light controller

The Raspberry Pi and the relay board must work in a somewhat harsh environment. The museum moved to Perris, CA because the hot dry climate is good for the  artifacts. However, the climate is not good for the electronic parts. Most of the components sit in a cast iron box, painted black, with no ventilation, in a semi-desert. We are not certain of how hot it gets inside, but the 3d printed hinges we implemented in the box melted. Fortunately, all of the other parts are still working properly.

Now, you might be wondering why it takes so many relays to control one signal. The ACME traffic light is not a simple signal. There are arms, lights, and a bell. So, the relays are for:

  1. Red Light
  2. Green Light
  3. Yellow Light
  4. Motor power
  5. Motor direction
  6. Bell
  7. Fold (Keeps the arms from extending when returning them to the housing.)

And everything must be doubled because we have two signal heads.

Some additional relays were needed since the arm motor works by shorting two wires and applying power to a third. To change direction, you change which wires are shorted and which gets power. This would have been possible with two relays on the 16-channel board, but in this configuration, it would be possible for a software glitch to damage the motor. To ensure that would not happen we used a DPDT relay which provided a hardware interlock. Also, the motor, fold magnet, and bell all use big A/C coils. When these are turned off they generate a huge electric pulse. This does nasty things to the Raspberry Pi. (Funny enough the board has no problem.) To get around this problem three zero crossing solid state relays were added. By turning off the coils when no voltage is present you avoid the pulse problem.

Railroad equipment is designed to last a long time. The last railroad relay I used had an inspection sticker on it of 1910 (that’s when it was taken out of service, not when it was made). I don’t know if the new parts will last as long, but so far, the new parts have been very reliable in a challenging environment.

Watch the demo video below:

Author of the project: Eduardo Martinez

Seeed Fusion OPL Enables Complete PCB Manufacture and Assembly in One Week at Low Cost

What is the Seeed OPL?

The Seeed Fusion Open Parts Library or OPL is a tailored catalog of over 600 carefully selected components available for use in Seeed Fusion’s PCB assembly service. From capacitors and connectors to ICs and displays, these parts are always in-stock and guaranteed to be cheaper than externally sourced parts. By using these components in Seeed’s PCBA service, you will save time and money and at great convenience.

More Reliable

Components from the OPL are sourced from Seeed’s long-term partners. They are tried and tested in Seeed’s own products and undergo the same strict quality control procedures. And since there is always stock, if one part is defective it can easily be replaced. Arguably this is better than outsourcing from a reliable distributor such as DigiKey since outsourced parts cannot be easily replaced and may have been damaged while traveling halfway across the world.

More Convenient

The Seeed OPL was designed for convenience and simplicity. Seeed partnered with PCB design giants Eagle and KiCad to produce the Seeed OPL component libraries, so you can just download the packages and start designing. The resulting design is guaranteed to be compatible with the Seeed Fusion OPL and PCB Assembly service, so no more wasting hours checking availability and compatibility with suppliers.

There is also plenty to choose from; the Seeed OPL does not just include passive parts but many that are utilized in Seeed products and more. Hand-selected by our engineers, the parts are decided on based on customer popularity and feedback. Most recently, in response to the increasing interest in IoT, we introduced Particle’s popular P0 and P1 Wifi modules into our stock.



Typically, the lead time for PCBA is 25 working days. That is over a month before you can begin testing the design and make amendments if necessary. For some, that is much too long. But by sourcing all parts from the OPL, the lead time can be reduced to as short as one week.

When a PCBA order is placed, Seeed will simultaneously begin PCB manufacture and order the parts. Both the PCBs and parts are needed to begin assembly, assembly itself can be completed from 8 hours when all the materials arrive. The long lead time for standard PCBA is a result of the long import procedures which cannot be rushed. But since the OPL parts are always in stock, using these will effectively reduce the lead time for parts procurement to zero, speeding up PCBA and allowing greater control over the overall lead time.


Since Seeed OPL parts are purchased in bulk from trusted partners, the cost per component is guaranteed to be significantly lower compared to buying them in small handfuls, and you won’t need to worry about delivery costs. These cost savings are passed on directly to customers. What’s more, this month only, Seeed Fusion has waivered the cost of over 400 parts from the OPL, so you can use them completely free, no restrictions applied.

The Seeed Fusion OPL has already helped many of you reach critical deadlines and slash costs, and we hope it can continue to do so. We would love to hear if you have any new additions you would like to see in the OPL or other suggestions regarding any of our services. Please drop us a message at The library and Fusion as a whole is continuously being enhanced thanks to feedback from you.

Don’t forget, Seeed Fusion is currently holding huge Spring sales across PCB and PCBA services. For the last three days, get 10% off PCB orders, $50 off PCBA orders and over 400 OPL completely free!

Watch the factory tour of Seeed Studio:

The 2018 Hackaday Prize has launched

The 2018 Hackaday Prize has been announced. This is the fifth contest of the annual Hackaday Prize series and is jointly sponsored by Digi-Key and Supplyframe. This year’s challenge to the hardware hackers across the globe is to “Build Hope” through open source hardware projects. Over the past 4 years, the Hackaday Prize contest has already given away nearly $1 million to the innovative makers who contributed towards building awesome stuffs to make this world a better place. This year has following 5 themed challenges that run in series:

    • Hardware Design Challenge: 3/12 – 4/23
    • Robotics Module Challenge: 4/23 – 6/4
    • Power Harvesting Challenge: 6/4 – 7/16
    • Human – Computer Interface Challenge: 7/16 – 8/27
    • Musical Instrument Challenge: 8/27 – 10/8

      The Hackaday 2018 Prize has launched

      The Hackaday 2018 Prize has launched

The first round of the competition is the “Open Hardware Design Challenge,” where entrants are encouraged to design the boldest plan they can dream up. Prototypes are not necessary for this challenge – only pictures, charts and theory are required. The Open Hardware Design Challenge kicks off today and runs through April 23.

The remaining rounds are the “Robotics Module Challenge” (April 23-June 4), “Power Harvesting Challenge” (June 4-July 16), “Human-Computer Interface Challenge” (July 16-Aug. 27) and the “Innovative Musical Instrument Challenge” (Aug. 27-Oct. 8).

“We’re excited to partner with Hackaday for another year of challenging inventors to be curious, creative and determined. The Hackaday Prize contest aligns with Digi-Key’s vision to encourage and enable innovation in technology that will solve problems and advance civilization. With the amazing projects we’ve seen in previous years, we can’t wait to see what the entrants create this year, ” said David Sandys, director, Business Ecosystem Development at Digi-Key. 


The top 20 entries from each challenge will win $1,000 and be considered for the Finals Round. The top five finalists, including the Grand Prize winner, will be announced at the Hackaday Superconference taking place Nov. 2-3 in Pasadena, California. The Grand Prize winner will be awarded $50,000 and considered for a residency at the Supplyframe DesignLab in Pasadena, California. The second-, third-, fourth- and fifth-place winners will receive $20,000, $15,000, $10,000 and $5,000, respectively.



In addition to cash prizes, participants will compete throughout the competition for most impressive, outlandish and otherwise notable projects. Although there is no cash value associated with these accomplishments, they do come along with bragging rights. Examples of possible Achievements include the Diva Plavalaguna Achievement (most unexpected musical instrument), the Sonic Screwdriver Achievement (hacks that seemingly do everything) and the Ender’s Achievement (most incredible student submission).

The official rules and other details about the 2018 Hackaday Prize can be found at the Hackaday Prize page.

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