Axe the Overpriced Sensors

If you put a rail on it, it is going to blow your budget. That is the reality when it comes to the rack mountable computing equipment that fills up data centers. In all fairness, these systems tend to be equipped with specialized hardware and redundant components that (mostly) justify the cost. But what if you just want to do something that should be simple — like keeping an eye on the temperature of the server room? In all likelihood, you will only have a selection of very expensive enterprise-grade options, loaded with unnecessary features, to choose between.

Openviro Axe PoE is an open source temperature monitor for servers and rack mount equipment that aims to do one just thing, and do it well — on a budget.

Most servers contain internal temperature sensors, but these readings are often inaccurate due to heat generated by internal components. Additionally, many enterprise-grade sensors only provide temperature data in 1°C increments, which limits their usefulness for tracking gradual environmental changes.

The Openviro Axe PoE solves these issues by utilizing a Bosch BME280 environmental sensor, capable of delivering temperature readings with an accuracy of ±0.5°C and a fidelity of 0.01°C. This precision enables IT professionals to monitor environmental trends in real time, helping to prevent overheating-related failures before they occur.

Unlike traditional systems, the Openviro Axe PoE allows users to deploy multiple temperature probes to track both intake and exhaust temperatures within a rack, ensuring a more comprehensive view of airflow and heat distribution.

The Openviro Axe PoE is built around the Raspberry Pi RP2040 microcontroller and is designed to easily integrate into existing network environments. It supports SNMP v1 and v2c for straightforward device management, with SNMP v3 support currently in beta. Since the device is configured via a direct serial console, there is no need for SSH or a web-based interface, reducing potential security vulnerabilities.

To further simplify deployment, the sensor probes are housed in compact enclosures with embedded magnets, allowing them to be easily mounted within a server rack. They connect to the main unit — the "brain" of the system — via standard RJ12 6P6C cables, which are both affordable and easy to replace.

Unlike many commercial solutions, Openviro Axe PoE is open source, allowing users to modify and improve its firmware. The project’s developers plan to release the firmware on GitHub following the conclusion of their funding campaign, further fostering community-driven enhancements.

The Crowd Supply campaign has not launched just yet, but you can sign up to be among the first to receive updates. Prices for the units have not yet been announced, but it is expected to be very cost-effective, and considering the low-cost hardware that is going into the build, that goal should pan out.