Product Overview

Have you ever seen electronic boards hanging on a single wire? If not, check out the amusing image of TrigoPi boards hanged on a wire. Seriously though, if you are familiar with the 1-wire bus protocol, you’ll appreciate the elegance and simplicity of this approach.

TrigoPi’s ECOM-USB1W is a USB to 1-wire adapter board (see Figure 2) that enables a PC host to control a 1-wire interface. It acts as a master on the 1-wire bus, capable of communicating with and manipulating a wide range of 1-wire devices such as temperature sensors, airflow sensors, barometric pressure sensors, and more (see Figure 5).

Technical Highlights

The ECOM-USB1W incorporates advanced 1-wire features such as Active Pull-Up and Strong Pull-Up implemented with an external MOSFET transistor. These features significantly enhance the robustness and speed of the 1-wire bus compared to traditional passive pull-ups.

Active pull-up accelerates the rising edge of the bus voltage by providing a controlled current source during signal recovery, reducing signal distortion and improving communication reliability, especially on longer or heavily loaded buses. Strong pull-up supplies a higher current to power devices during energy-intensive operations such as temperature conversions or EEPROM writes, ensuring proper device function without communication errors.

The adapter also supports an optional auxiliary voltage input to increase the 1-wire network’s power robustness. It can reliably operate with or without this auxiliary input, providing flexibility for different network sizes and power demands. Protection features include over-voltage protection, reverse polarity voltage protection, and electrostatic discharge (ESD) protection on the data line (DQ). The design also ensures excellent impedance matching on the DQ line, minimizing signal reflections and enabling stable operation across multiple network devices.

Integration & Applications

The ECOM-USB1W works seamlessly with the TrigoPi USB1W SDK (see Figure 4), which encapsulates basic 1-wire functionalities (L0) as well as advanced feature sets (L1) tailored for applications using TrigoPi’s 1-wire products, including temperature and airflow sensors.

Typical applications include distributed environmental monitoring in industrial plants, HVAC systems, data centers, and cold chain logistics. The 1-wire bus’s simplicity allows multiple sensor boards to be “hanged on a wire,” minimizing wiring complexity and installation costs while enabling scalable sensor networks.

Variants & Support

The ECOM-USB1W can operate with or without the auxiliary input voltage, adapting to different network power requirements. Built-in protections and superb impedance matching ensure reliable communication across various network topologies and device counts. TrigoPi offers design-in support and qualification services to facilitate integration and ensure robust operation in demanding industrial environments.

Safety & Reliability Notes

To maintain reliable 1-wire network operation, proper wiring topology and cable selection are essential. Linear or daisy-chain wiring with minimal stubs is recommended to reduce signal reflections. Shielded twisted-pair cables help mitigate electromagnetic interference in noisy industrial environments. The active and strong pull-up features significantly extend reliable network length and device count compared to passive pull-ups alone.

Over-voltage and reverse polarity protections safeguard the adapter and devices from wiring errors, but careful installation and grounding remain critical. The adapter’s impedance matching and ESD protections further enhance system robustness.

Implementation Tips

• Use shielded twisted-pair cabling to reduce noise and crosstalk.
• Adopt linear bus topologies with short, minimal stubs.
• Enable active pull-up mode for longer cables or many devices.
• Use auxiliary voltage input for networks with high device count or power-hungry sensors.
• Verify device addressing and timing with the TrigoPi USB1W SDK diagnostic tools.
• Ensure proper grounding and avoid routing cables near high-power equipment.

Call to Action

If you are designing sensor networks that require reliable, scalable, and easy-to-integrate 1-wire bus control, the TrigoPi ECOM-USB1W adapter combined with the USB1W SDK offers a professional-grade solution. We refined this approach at TrigoPi in real projects—reach out if you’d like to see how it applies to your case or to request datasheets, evaluation kits, or design support.

References

• https://resources.altium.com/p/7-serial-communications-protocols-1-wire
• https://www.analog.com/en/resources/technical-articles/guide-to-1wire-communication.html
• https://www.sika-usa.com/sika-blog-us/sensors-for-temperature-and-humidity-with-1-wirer-bus-interface/
• https://www.allaboutcircuits.com/technical-articles/low-pin-count-serial-communication-introduction-to-the-1-wire-bus/
• https://controlbyweb.com/x406/
• https://www.analog.com/en/resources/technical-articles/how-to-power-the-extended-features-of-1wire-devices.html
• https://www.analog.com/en/resources/technical-articles/choosing-right-1-wire-master-for-embedded-applications.html
• https://www.analog.com/en/resources/technical-articles/configurations-of-1wire-timing-of-the-ds2480b.html
• https://www.analog.com/en/resources/app-notes/reading-and-writing-1wirereg-devices-through-serial-interfaces.html