Wireless Communication

2 posts

toss3 min readCurated summary

It Almost Ended Up Ugly - The Making of Toss Front 2

Toss redesigned its Front 2 payment terminal by addressing real-world usability problems rather than settling for technically workable solutions. The redesign moved NFC to the front, made the card reader field-replaceable, and reworked the internal structure to simplify removal. The result was a smaller, cleaner device that improved both customer experience and repairability. ## Moving NFC to the Front - The first-generation terminal placed NFC on the right side because other components interfered with the signal. - This was inconvenient in narrow retail spaces, where users had little room to tap cards or phones. - Several alternatives were tested: - Moving the card reader upward made card insertion awkward and strained users’ wrists. - Enlarging the top made the vertically oriented terminal look excessively long and displaced the camera, complicating barcode and face-payment use. - Placing NFC around the camera caused interference, producing camera shake and reducing recognition accuracy. - The team reframed the problem by asking whether the display’s metal backing could be replaced. - A customized plastic backing allowed NFC signals to pass through while reinforced glass preserved the display’s rigidity. - Despite higher manufacturing complexity and cost, the design was successfully mass-produced, enabling reliable front-facing NFC without sacrificing appearance. ## Designing a Replaceable Card Reader - The first-generation card reader was integrated into the main body, so failures required repairing or replacing the entire terminal. - Repairs took more than a week on average, forcing stores to use backup devices and distributors to maintain extra inventory. - Front 2 introduced a docked, replaceable card reader designed for easy on-site replacement. - A USB-C connector was selected because users already understand how to connect and disconnect it. - The connector provided stable attachment without exposing additional brackets or mechanisms, preserving the product’s clean appearance. ## Making Removal Simple - Once the reader used USB-C, the team needed a way to remove it without adding buttons, levers, or protruding parts. - The simplest approach was to insert the reader from the front and push it out from behind, but existing power and network connections blocked the necessary space. - Instead of adding another mechanism, the team redesigned the internal layout from scratch. - The circuit board and connectors were tilted toward the top of the device, requiring redesigned and inverted cable components. - This created enough room to remove the reader without tools. - The revised layout also made the cables easier to see and connect. ## Results of Front 2 - Front-facing NFC made payments more natural on crowded counters. - The USB-C dock reduced the difficulty of replacing a failed card reader. - The terminal became smaller while retaining its visual simplicity and design quality. - Front 2 surpassed the first generation’s sales immediately after launch, while previous customer complaints shifted toward positive feedback. ## Building Quality Through Persistent Questions - The article argues that product quality comes from repeatedly challenging an acceptable technical solution. - The team focused on finding answers that were right for users and the overall product experience, not merely answers that functioned. - For similar design problems, the recommended questions are: - Can everyone use the design easily, including in edge cases? - What is the fundamental problem? - Is the current solution truly the best one? - If not, can the problem and solution direction be redefined? The practical lesson is to keep revisiting the problem until the solution is not only feasible, but genuinely appropriate for users.

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datadog3 min readCurated summary

The Old Datadog and the Sea

Wouter de Bie describes upgrading his 1992 Hunter Legend sailboat, *Second Wind*, into a connected, data-driven vessel. His goals were to unify onboard instruments, improve safety with vessel tracking, add accurate wind measurements, and collect data for later analysis. The central solution was an NMEA 2000 network, which allowed compatible devices to share data and power over a single backbone. ## Building a Unified Instrument Network - The boat originally had a depth sounder, speedometer, autopilot, chartplotter, and GPS, but the systems were not centrally connected. - The existing Raymarine equipment used SeatalkNG, which is compatible with NMEA 2000 despite having different cables and connectors. - The older speed and depth displays used NMEA 0183 rather than NMEA 2000. - Instead of adding protocol converters, Wouter replaced the older displays with new NMEA 2000-compatible instruments. - Once connected to the backbone, speed and depth data appeared on the chartplotter. ## Why NMEA 2000 Was Chosen - NMEA 2000 is similar to the CAN bus used in automobiles. - Devices connect to a shared backbone and broadcast small data messages for other equipment to consume. - The network operates at 250 kbit/s, which is sufficient for marine instruments. - Its cables carry both power and data, reducing wiring complexity. - Most marine electronics vendors support the standard. ## Improving Safety with AIS - Wouter added an Automatic Identification System (AIS) transponder to detect nearby vessels. - AIS broadcasts a vessel’s name, identifier, speed, heading, and coordinates over VHF radio. - The system only detects AIS-equipped vessels within line of sight, but offers a lower-cost alternative to radar. - After installing the transponder and routing its antenna cable to the stern, nearby ships appeared on the chartplotter. - The transponder’s built-in GPS also supplied positioning data to the NMEA 2000 network. ## Adding Wind Measurements - The original wind indicator was only an analog vane, requiring Wouter to look up at the mast and providing no wind-speed measurement. - He purchased a NMEA 2000 wind transducer and cockpit display. - The transducer measures wind angle with a vane and wind speed with a rotor, typically from the top of the mast. - Installation required routing a cable through the mast and boat. - A friend was hoisted up the mast on a calm evening to drill the mounting hole and install the sensor. The project demonstrates how replacing incompatible legacy instruments and connecting modern devices through NMEA 2000 can turn a boat into an integrated safety and analytics platform. Once all sensor data is centralized, it can support both better sailing decisions and longer-term analysis of performance and conditions.

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