The Amp Hour

Robert Fennis joins Chris to demystify the black magic of RF and talk about his open-source, Python-based 3D electromagnetic solver, EMerge. They discuss why simulation is like building a pyramid of knowledge, how silk screen can completely de-tune a patch antenna, and Robert’s quest to build the “IKEA of FEM solvers” so hardware developers everywhere can simulate their designs without relying on insanely expensive proprietary software.

Dave and Chris celebrate 16 years of the show (1st episode was August 10th, 2010) by launching a brand-new static website featuring searchable transcripts and a “pissed-old amber” SVG scope with a working focus knob–and links to merch!. They also discuss Dave’s new employee, 10 cent RISC-V debuggers, and why naming your startup after an un-Googleable Australian cryptid is a bad move

Dr Greg Charvat, CTO and co-founder of Teradar, joins Chris for a 5th appearance on The Amp Hour to talk about how terahertz frequency radar will revolutionize the automotive space and far outstrips the capabilities of LIDAR and Blobbology

Alex Haro, CEO of Hubble, joins Chris to talk about building a network of terrestrial and space (!) based Bluetooth infrastructure to track low power devices across the globe, without a data plan or a GPS module onboard.

Welcome Alex Haro, CEO of Hubble

Chris welcomes Alex Haro, co-founder and CEO of Hubble, to discuss the ambitious task of connecting billions of Bluetooth devices directly to space

The “banner level spec”: Hubble enables any off-the-shelf Bluetooth chip to communicate with low Earth orbit satellites using a software-only firmware update

Alex describes the system as a global “Find My” for enterprise that also handles sensor readings and arbitrary data

Addressing the “Bluetooth in space” skepticism: Alex explains that while the standard is optimized for high-fidelity audio, the chips can be repurposed to emit a custom software-defined waveform in the 2.4 GHz band

The true innovation is on the satellite side: massive antenna arrays with thousands of elements perform advanced digital beamforming to pick up weak signals (0-20 dBm) from hundreds of kilometers away

The “Dinner Table Analogy”: Traditional networks “yell” to be heard, but Hubble has the device talk slower (lower bit rate) and enunciate (error correction) while the satellite uses thousands of “microphones” to isolate a single voice

Why Bluetooth instead of LoRa? Hubble co-founder and CTO of Ben Wild, is the architect of Amazon Sidewalk. He chose Bluetooth because it is globally ubiquitous and the 2.4 GHz band is unlicensed worldwide

Technical trade-off: While LoRa uses spread spectrum chirps, 2.4 GHz allows for much smaller antenna arrays on the satellites compared to the 900 MHz band

The hybrid network approach: Devices use the same SDK to communicate via a crowdsourced terrestrial network (apps and gateways) or directly to satellites when out of range

Constellation roadmap: Hubble currently has four production satellites in orbit (covering the globe twice daily) and aims for 64 satellites by 2029 for continuous real-time coverage

Removing the GPS chip: By using Angle of Arrival (AoA) on the satellite, Hubble can determine a device’s location to within tens of meters, reducing BOM costs and power consumption

Future “Reverse GPS”: Once multiple satellites are overhead, Hubble can combine AoA with Time of Flight (ToF) measurements for even higher accuracy

Network capacity: Each 10km satellite beam can handle roughly 100,000 simultaneous devices before hitting saturation, with terrestrial gateways offloading density in major metros

Dealing with the “grumpy engineer”: Alex discusses lowering friction for developers by investing in the Zephyr Project and partnering with Texas Instruments to pre-flash the Hubble stack on Bluetooth SOCs

Stack coexistence: The Hubble SDK allows the radio to time-slice, maintaining a standard Bluetooth connection to a phone while sending satellite packets during idle periods

Payload specs: Data packets are 13 bytes, transmitted at 400 bits per second

Business model: Pricing starts around $2 per device per month and scales down with volume to hit the “price elasticity” needed for tracking billions of assets

Enterprise use cases: From tracking shipping pallets to monitor loss, to cold chain monitoring for pharmaceuticals and agriculture

The SpaceX experience: Alex describes the “visceral” feeling of the double sonic booms from the Falcon 9 landing during their launch party

Find out more at hubble.com (or hub of BLE)