Great Scott Gadgets is on Mastodon! You’ll get a lot of the same information as you get on our other social media profiles, but if Mastodon is your platform preference, we now have you covered.

The July recipient for the Great Scott Gadgets Free Stuff Program is Joona. Joona plans to use the YARD Stick One we are sending him to develop and test radios. He will be writing documentation and creating tutorials on his projects.

Note: This is a crosspost of a Cynthion update on Crowd Supply: https://www.crowdsupply.com/great-scott-gadgets/cynthion/updates/cynthion-delivery-timeline-update

Hello, campaign backers and other supporters of Cynthion and Great Scott Gadgets! In this update, we hoped to tell you that manufacturing was in progress and that we were getting close to delivering the first Cynthions to you. Unfortunately, we have encountered more delays while getting the hardware ready to go to manufacturing.

The first delay was caused by another component availability barrier, which is now solved. After our last hardware update, we placed an order with our contract manufacturer for the additional components added to the Cynthion hardware design in r0.6. At the time of engineering r0.6, all of the new components added in this major revision were widely available, and we had no indications that there would be issues acquiring them. However, when we received the BOM quote for these additional components from our contract manufacturer, we learned that the power monitor part we had planned to use, PAC1954T-E/J6CX, was no longer in stock, and the quoted lead time was 20 weeks. Focused on getting the product delivered to you on time, we ordered a substitute part right away, and our engineering team immediately got to work on another hardware revision to instead use a PAC1954 package that was in stock, PAC1954T-E/4MX. This revision was relatively minor, but we did have to order another round of prototypes for verification and testing. Each time we order and test a new round of prototypes, the process takes 3-4 weeks. We named this new Cynthion revision r1.1.0 and went to an independent test lab for the necessary pre-compliance testing before ordering the production PCBs.

Before going to manufacturing or putting Cynthion on the market, we must certify that the final product conforms with applicable regulations and standards in all the countries we will be shipping to. One of the important standards Cynthion must comply with is electromagnetic compatibility (EMC). Cynthion’s compliance with EMC includes two components: emissions and immunity. Emissions compliance means that the Cynthion won’t emit electromagnetic interference (EMI) that can adversely affect other devices in its environment, and immunity compliance ensures that the Cynthion itself won’t be affected by electrostatic discharge (ESD). So far, we have had two rounds of testing in an independent EMC testing lab, each evaluating Cynthion on the emissions and immunity standards we’ve identified as applicable to Cynthion. In the first round of testing, Cynthion passed neither emissions nor immunity tests. By the second round, a couple of weeks later, the engineering team had solved the immunity problems, and Cynthion passed with flying colors– no such luck with the emissions portion of the test.

Since then, we have worked very hard to solve the EMC emissions issues with Cynthion. The engineering team identified software and gateware modifications that significantly reduced emissions and also found some small hardware changes that helped. Although great progress was made in a short period of time, it became apparent that a new hardware revision (r1.2.0) would be required to test modifications that we think will clear the final hurdle. As of today, we are waiting for another round of prototypes to be delivered so that we can test the new revision, and we hope that these will be the pre-manufacturing prototypes that will successfully pass EMC at the lab.

Although it is only possible to precisely estimate when Cynthion will ship once we have solved the emissions issues and manufacturing is underway, you will see that the expected delivery date for Cynthion fulfillment has changed to January 31st, 2024, which is our best estimate. In this new proposed timeline, we allow ourselves another month to resolve the EMC emissions issues and pass pre-compliance testing. After that, we estimate that manufacturing and quality control testing will take about three months, and we are allowing another two months for logistics and fulfillment. We will have a better idea of whether this timeline is realistic or not after the next round of EMC pre-compliance testing at the independent lab, and we will be sure to update you again if things change again with the timeline. In the meantime, we assure you that delivering Cynthion to you is our priority, and thank you for your patience as we continue to work hard to accomplish this goal we have been working towards for so long. Please accept our apologies for not updating you as often as we’d like to. The engineers who are best equipped to write these updates are very busy working on getting Cynthion to you as soon as possible!

The June recipient for the Great Scott Gadgets Free Stuff Program is Daniel. Dan is planning to use the HackRF One we are sending him to run workshops in his school and with his amateur radio group. He will also be creating videos with his new HackRF One on his YouTube channel “Radio Dan ZL2DTL”. Please welcome Radio Dan to the software-defined radio community!

The May recipient for the Great Scott Gadgets Free Stuff Program is the UCLA IEEE Wireless, RF, and Analog Project (WRAP). Participants in this club have the opportunity to learn hands-on radio engineering skills by designing, building, and testing a 2-way radio system capable of operating in the 100s of MHz. Through this project, students can learn digital and analog radio techniques like implementing filters and a mixer from discrete diodes and using coils for up/downconversion. WRAP asked for a HackRF One to aid in debugging wireless links, where they will use the HackRF One both as a modulated waveform generator for receiver testing and a real-time spectrum analyzer for transmitter and device debugging. We really look forward to seeing their end projects.

Note: This is a crosspost of a Cynthion update on Crowd Supply: https://www.crowdsupply.com/great-scott-gadgets/cynthion/updates/updated-cynthion-enclosure

About a year ago, we announced an FPGA substitution on the Cynthion project due to supply chain issues. Since then, the Great Scott Gadgets team has redesigned and enlarged the Cynthion board to accommodate the larger FPGA, and Timon has adapted the enclosure to fit the larger board.

The updated Cynthion enclosure measures 60 mm (2.36 inches) in width, 72 mm (2.83 inches) in length, and 15 mm (.59 inches) in height. The weight of the enclosure with a Cynthion inside and all hardware, comes to 99.5 grams. In comparison to the previous enclosure, the new one is 8 mm wider, 7 mm longer, 1 mm taller, and 3.5 grams lighter due to extra milling for Pmod connectors and other small changes.

Once I received the 3D model files from Timon, I got to work designing the final graphics for the Cynthion enclosure, which are shown in the image below.

In this image, the black lines are the edges of the enclosure, connector holes, and hardware holes. The blue text and images are the graphics and labels that will be etched into the case. Once etched, these graphics will appear white-grey in colour. A rendering of the case is below:

The differences from our early enclosure design include a complete change in graphics on the top of the case, moving the port labels to the edges, adding labels for the Pmods, and a debossed (not etched!) Great Scott Gadgets logo on the back.

The April recipient for the Great Scott Gadgets Free Stuff Program is Adnane. Adnane is a software development and cybersecurity student in SoliCode School in Tangier, Morocco. He is always looking for new tools and technologies to enhance his learning and explore new avenues in the field. Adnane is planning to use his HackRF One to learn more about wireless security testing, digital signal analysis, and software-defined radio. He will share his knowledge and skills in the SoliCode Cybersecurity Club. Good luck and have fun!

The Great Scott Gadgets team is thrilled to announce our newest research and development project: a Universal Radio Test Instrument (URTI). We have decided to call this project URTI as a working title. With the support of ARDC in partnership with TAPR, we aim to develop an open-source SDR platform with an unparalleled set of radio investigation and experimentation functions in one versatile device. URTI will offer radio amateurs, researchers, educators, and professionals an affordable, compact RF test tool that could be used in place of multiple expensive pieces of traditional radio test equipment.

Design and Functionality

Our goal for URTI is to design a single hardware platform capable of serving as many popular types of one-port or two-port RF test instruments. We plan to build a directional coupler into a wideband, full-duplex SDR platform to enable URTI to function as a:

• spectrum analyzer
• vector network analyzer
• vector signal generator
• vector signal analyzer
• antenna analyzer
• power meter
• frequency counter
• full-duplex SDR transceiver

Incorporating these test equipment functions into a compact form factor with a handheld user interface will make URTI portable and convenient to use in the field. We also plan to develop a lower-cost variant that will provide the same test equipment functions but as a computer peripheral device without the handheld user interface, making the tool more accessible for every budget.

Development Plans

The Great Scott Gadgets engineering team will develop URTI in eight overlapping phases. These phases will include:

• Mainboard component selection and sub-circuit evaluation
• Initial mainboard hardware design
• User interface board component and sub-circuit evaluation
• Mainboard firmware and gateware development
• Host software development to enable use of the mainboard as a USB peripheral
• Final mainboard prototype design
• User interface board hardware design
• Handheld user interface firmware development

Once we have a complete and fully documented final design, we plan to assemble and distribute 50 prototypes of the USB peripheral version and 50 prototypes of the handheld version to select beta testers to promote feedback and community involvement. We have already started working on the first phase of development: mainboard component selection and sub-circuit evaluation. Our priority is selecting components that are widely available and cost-effective so the completed design can remain relevant and accessible for as long as possible.

All phases of the URTI project will be published concurrently with development in public repositories within the Great Scott Gadgets organization on GitHub. In keeping with Great Scott Gadgets’ commitment to putting open-source tools into the hands of innovative people, we will publish all hardware, software, firmware, and documentation for URTI under open-source licenses, making these resources available to all. You can view our current progress on URTI in the lab notes repository on GitHub.

Thank Yous and Getting Involved

We are excited to bring the URTI project to life over the coming year, and we hope it will transform how people experiment with radio. We thank ARDC and TAPR for supporting this project and contributing financial resources to make it happen!

We would love to hear your feedback on this project and invite you to join us on our Discord server to chat about this or other Great Scott Gadgets projects.

The March recipient for the Great Scott Gadgets Free Stuff Program is Jan. Jan is the author and maintainer of RadioLib, an open-source library for embedded devices controlling various wireless radio modules like SX1276, CC1101 or RF69.

We are sending Jan a HackRF One to aid in the development of RadioLib. Until now, Jan has been doing development using an RTL dongle. The lack of TX ability, and other issues, have made the dongle a bit less than practical. We hope the HackRF One helps, and we look forward to watching this project continue to evolve!

Note: This is a crosspost of a Cynthion update on Crowd Supply: https://www.crowdsupply.com/great-scott-gadgets/cynthion/updates/cynthion-hardware-design-update.

We’ve completed the Cynthion r0.6 design! As mentioned in previous updates we needed to modify the design to accommodate new components due to supply chain issues. In this revision additional changes were made to resolve some problems beta testers identified with both power input and power output.

Issues Found During Beta Testing

Power input issues: When you plug Cynthion into a host computer, it is expected that Cynthion powers up and that the host computer will recognize that a device has been attached. Our beta testers found a couple of situations in which those things would not happen reliably. These scenarios were caused by a confirmed issue with excessive reverse leakage through a diode and a suspected issue with loading of the CC pins on the USB Type-C connectors.

Power output issues: Cynthion can pass power from a host computer (either the control host or a target host) through to a target device. Although this worked reliably, there was a problem that caused excessive power consumption and another problem that could theoretically damage a component on Cynthion.

Rethinking Power Distribution

As we investigated various power input and output issues over the past year or so, we sketched solutions planned for r0.6. When it came time to design r0.6, however, we realized that those solutions were insufficient.

Additionally, we realized that older versions of Cynthion were vulnerable to damage from high voltage input on any of the USB Type-C connectors. Originally designed with Micro-B connectors, Cynthion was later updated with Type-C connectors, introducing a much greater probability of accidental high voltage.

Micro-B connectors are intended to carry 5 V power, but Type-C connectors were designed to support up to 20 V, later extended to 48 V. USB hosts and power supplies are supposed to supply only 5 V unless the device asks for a higher voltage, but a noncompliant implementation could supply up to 20 V without negotiation.

Partly out of concern for overvoltage, we had implemented very limited Power Delivery (PD) capabilities in previous hardware revisions, minimizing the probability of input voltages higher than 5 V. However, our PD implementation may have contributed to other problems, and it did nothing to protect Cynthion from overvoltage from a noncompliant power supply.

We decided to completely rethink both power input and power output. After multiple rounds of design, simulation, and test, we’re happy to report that Cynthion’s capabilities are better than ever before!

image caption: a prototype board, essentially a Cynthion with everything removed except power distribution and monitoring

What’s New in r0.6

The USB ports are now renamed:

• CONTROL is the primary port for control of Cynthion. Both the FPGA and the on-board debugger are now controlled over this port, so a second connection to the control host is no longer required.

• TARGET C connects to a target host.

• TARGET A connects to a target device and is directly connected to TARGET C, passing through data signals and allowing USB analysis.

• AUX is an auxiliary port that can be used for various purposes, including MitM or as a secondary control port for development.

Cynthion now supports power passthrough up to 20 V, the highest voltage allowed in PD’s Standard Power Range (SPR). Power can now pass through to the AUX port in addition to the TARGET ports. PD’s Extended Power Range (EPR) is not supported.

A 5 V power supply is still required on either CONTROL or AUX to power Cynthion itself, but the hardware now allows the user to select which port to use if 5 V supplies are available on both ports. Overvoltage protection automatically shuts off either input if it exceeds 5.5 V.

Power input and power passthrough are now two separate functions, no longer entangled with one another. All power output is strictly passthrough, not an output of an internal supply rail. Overvoltage shutoff of an input does not affect passthrough. There is no longer a diode drop reducing passthrough voltage.

All four ports now feature voltage and current monitoring, allowing Cynthion to measure passthrough power as well as its own power usage. The power monitoring capability can be used to implement flexible overvoltage, overcurrent, or reverse current protection for external hosts or devices, though with a slower response time than Cynthion’s internal overvoltage protection.

TARGET C and AUX now each have a Type-C controller implementing bidirectional PD communication on the CC pins. This significant improvement in PD capabilities was made possible in part by the power distribution redesign. The Type-C controller additionally allows VCONN output that can be used, for example, to power electronically marked cables.

A new USER button provides input to the FPGA, allowing direct interaction with gateware running on Cynthion.

The Pmod connectors are moved to the same edge of the board making Cynthion compatible with dual Pmods. A new mezzanine connector provides additional expansion capability.

Cynthion is now physically larger. The PCB dimensions increased from 48x48 mm to 56x56 mm. This will accommodate future revisions with physically larger FPGA packages or other components. During the r0.6 design phase we unexpectedly received some delayed components which we will use in the first production to reduce risk, but we need room to allow future use of alternative parts purchased during the shortage.

New mounting holes in the corners allow the PCB to be firmly fastened to an enclosure. 3D render of Cynthion r0.6

Next Steps

Prototypes of Cynthion r0.6 have been assembled, and we are testing them now. We anticipate one more hardware revision before production, but we expect it to include only minor updates. Initial testing of r0.6 is going very well, probably because we already prototyped smaller sections of it separately.

Taylor and Martin are now working hard on designing a test jig and software for factory testing. Much of this work couldn’t be done until the r0.6 redesign was complete, but we are now making rapid progress.

Timon has already completed an update of the enclosure design for new form factor, and we will have samples made very soon. Once we have samples that pass inspection we’ll be able to design packaging.

All of these steps will take time, and they were delayed by the r0.6 redesign effort. As a result, we expect to begin shipping LUNA in August 2023 instead of June 2023, but we think the many improvements in the latest revision will be worth the wait. We’re thrilled to be making steady progress after many months of waiting and wondering about component availability.

We greatly appreciate your patience and continued support!