Build Your Own RF Lab: Scalar Network Analyzer

Whitney Knitter writes on Hackster about a simple scalar network analyzer that can be controlled by a Raspberry Pi for measuring the frequency response of filters and networks:

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Build Your Own RF Lab: Scalar Network Analyzer

With the popularity of wireless applications having become such a staple in the hobbyist community, the need for RF testing capabilities in the hobbyist realm has also increased. Anyone familiar with traditional RF test equipment knows that it is expensive. But challenges like this are what bring out the engineering creativity in this community. Steven Merrifield designed and laid out his own simple scalar network analyzer (SNA) using just a few IC chips. SNAs are handy for testing the frequency response of filters or networks.

A scalar network analyzer is used to test the amplitude of a device’s frequency response by outputting a sine wave sweeping over a certain frequency range (bandwidth) then measuring the amplitude of each incremental output frequency.

Thus if you directly connect the sine wave output of an SNA to its measurement input, then it will read a flat line of the same amplitude for each incremental output frequency of the sweep:

When a device is connected to the SNA, the amplitude of the sine wave at each frequency after going through the device will reflect the device’s frequency response over that bandwidth.

Merrifield’s design accomplishes an SNA’s functionality via implementation of a DDS Synthesizer chip, an ADC, and a logarithmic amplifier chip. The AD9850 DDS is responsible for outputting the sweeping sine wave while the AD8307 logarithmic amplifier conditions the signal input into the SNA for the log of the signal’s envelope before passing it on to the ADC for digitizing. A second AD8307 also conditions the output of the DDS and outputs it to a second channel of the ADC so that it can be used in software for compensation of any variations on the DDS’s output due to the effects of various loads of devices being tested.

The ADC outputs its digital measurements via an I2C interface to a GPIO header that matches the Raspberry Pi’s GPIO header pinout, but any desired MCU or FPGA could be used. The source code Merrifield wrote is in C, making it easy for porting across different platforms.

Check out Merrifield’s project logs here. He linked his PCB layout on OSH Park if you’re interested in ordering it and putting one of these together for your own lab!

Build Your Own RF Lab: Scalar Network Analyzer

DipDuino: Arduino-compatible slim as a DIP

AtomSoft has designed this Arduino-compatible board that’s as slim as a DIP chip:

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dipDuino Is an Arduino-Compatible Board That’s as Slim as a DIP Chip

Take up fewer rows on your breadboard with this ATmega328P-based board.

One reason the Arduino Nano became a popular form factor is that it fits onto a breadboard. The compact size is nice but makes the board a bit larger in the width dimension. To solve that issue, AtomSoftTech designed the dipDuino as an Arduino-compatible as narrow as a DIP package.

dipDuino has the same ATmega328P found in the other 8-bit Arduino boards like the Uno and Nano, however measures just 0.37 x 1.82 in (9.3 x 46.26 mm) in size. Its DIP package compatibility comes from the pin row to pin row pitch at 0.3 in (7.62mm).

The DIP-compatible form factor has all of the same pins found on those other boards: 13 digital, five analog, VCC, RESET, and GND. The silkscreen labels A4 and A5 as SDA and SCL since they have a shared function (same as the Uno and Nano).

The ATmega328P SMD packages have two extra analog inputs available that the DIP-style package does not. (This difference is why boards like the Pro Mini and Nano have A6 and A7.) Even though dipDuino has an SMD AVR chip, it does not break out the extra analog pins.

DipDuino: Arduino-compatible slim as a DIP

MappyDot Distance Measurement Badge

SensorDots created this standalone wearable badge that will show people how far away they are so they don’t accidentally run into you:
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MappyDot Distance Measurement Badge

This project will show you how to create a standalone application with the MappyDot Plus working as an I2C master with an I2C 7 segment display. This example can also be adapted for use with a wide range of different client I2C devices for standalone applications.

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Once you have assembled the 7 segment display, you can now hook everything up as per the schematics below. Provided your battery supply outputs a voltage between 2.8 and 5 volts, you don’t need to use a voltage regulator to supply this project. Using 4xAA 1.2v rechargable NiMH batteries is perfect for this setup. If using 1.5V alkaline batteries, you should consider using a voltage regulator (or a diode with a large voltage drop) or opt for only 3xAA alkaline batteries.

MappyDot Distance Measurement Badge

BadgeLove meetup in SF on October 18

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Hackster.io is hosting a BadgeLove meetup in San Francisco on Friday, October 18th:

Have you ever created a badge? Are you currently working on a badge? You are invited as a guest of honor to Hackster’s BadgeLove! Meetup. We want to take an evening to appreciate the hardware heroes who do the often thankless and frequently futile task of creating PCB artwork, shitty add-ons, and PCB badges. 

We are excited to toast the winners of last winter’s BadgeLove! contest on Hackster. Come in person, record a video or join via YouTube Live, and show us what you’ve built.

Screenshot from 2019-10-12 12-49-53

 

BadgeLove meetup in SF on October 18

Designing a PCB Ornament

Liz from Blitz City DIY wrote about the process of designing a PCB ornament:

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Designing a PCB Ornament

As the holidays approached this year, I felt a need to create a DIY gift for my family and friends. I struggled at first to find a medium. Should I 3D print something? Should I knit? But then it hit me: everyone loves blinky LEDs and I want to keep getting better at PCB design. I’ll do a PCB ornament!

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If you don’t have a traditional electronics background PCB design can seem scary, overwhelming and something that’s meant for more experienced people that have “real skills”. If you start simple and slowly add-in new methods and design features to your boards you’ll soon realize it isn’t so scary and that much like everything else in life it just takes practice and patience to learn. And once you have your first project on a custom PCB instead of a piece of perf board you’ll be hooked.

Designing a PCB Ornament

BadgeLove contest on Hackster.io

We are excited to announce this new contest with Hackster.io and Autodesk:

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BadgeLove!

BadgeLove by Hackster: The Blinkiest Badge Challenge on Earth! 

Win up to $5,000+ in prizes!

#BadgeLife is the new electronic graffiti. This form of art is in a league of its own, first popularized by DEFCON hackers, now boasts serious technical sophistication, a wicked artistic flair, peppered with political, cryptography, social, cultural and comical narratives, flashing LEDs and screens with add-ons galore.

You are invited to join our first, and certainly not last, BadgeLove challenge, sponsored by OSH ParkAutodesk EAGLE & Fusion 360, and Hackster.

Share your unique design with 700,000+ Hacksters and we will reward badge fanatics for their beautiful, weird, cool contributions.

BadgeLove contest on Hackster.io

New Charmware PCBs by Alex Glow

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Alex Glow from Hackster posted an update on the Charmware modular tech jewelry system:

New Charmware PCBs from OSH Park! (Pt. 1)

Sweet, a package from OSH Park! Time for an unboxing! Plus, see how to upload and order your own boards.

New Charmware PCBs from OSH Park! (Pt. 2)

Visit Hackster.io for more information on the project:

Charmware // Modular Tech Jewelry System

These mini PCB beads (PCBeads?) help you build wearable electronic circuits!

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New Charmware PCBs by Alex Glow

Google Android Things Meetup

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Hackster.io is organizing a Google Android Things Meetup in San Francisco on Thursday, January 18th:

Android Things Meetup (with Google)

Thursday, Jan 18, 2018, 6:00 PM

HAX San Francisco
479 Jessie Street San Francisco, CA

12 Hacksters Attending

GOOGLE AND HACKSTER PRESENT: Android Things – San Francisco: bit.ly/sf-thingsGoogle and Hackster have teamed up to host a night dedicated to Google’s Android Things in downtown San Francisco.Make sure to visit the Eventbrite page to register and save your spot for this event! bit.ly/sf-thingsHave you ever wanted to design and develop your own p…

Check out this Meetup →

Be sure to register on the Eventbrite page:

Google Android Things Meetup

Have you ever wanted to design and develop your own products? Android Things lets you build professional, mass-market products on a trusted platform without previous knowledge of embedded system design. With an easy-to-use software development platform based on Android Studio and access to the Android SDK you’ll be on your way to developing the next big IoT product.

Wayne Piekarski, a Developer Advocate from Google will be showcasing the capabilities of Android Things and how you can get started building your product with this platform.

Here’s a talk with Wayne Piekarski earlier this year at Google I/O:

From Prototype to Production Devices with Android Things (Google I/O ’17)

 

Google Android Things Meetup

OSHWi Octopus Badge by Gustavo Reynaga

Alex Glow of Hackster.io takes a look at the OSHWi octopus badge designed by Gustavo Reynaga:

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The design files and source code are available on GitHub:

hulkco/oshwi_2017

GReynaga has shared the board on OSH Park:

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Oshwi Badge HACKSTER Version Rev 1

 

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Order from OSH Park

OSHWi Octopus Badge by Gustavo Reynaga