PT100 Temperature Sensor Module MAX31865 – RAKwireless RAK12022

The RAKwireless RAK12022 adds an industrial-grade PT100 temperature interface to the WisBlock ecosystem. At its core is the MAX31865, an easy-to-use resistance-to-digital converter optimized for platinum RTDs. It’s a practical choice for engineers building prototypes, test rigs, or products that need reliable PT100 temperature readings with straightforward digital integration.

The module supports 2-wire, 3-wire, and 4-wire PT100 connections, letting you choose the wiring scheme that fits your accuracy and cabling needs. Data is read via an SPI-compatible interface. Internally, a precision delta-sigma ADC digitizes the ratio of RTD resistance to a reference resistor, providing a clean digital temperature pipeline for embedded systems.

For real deployments, the MAX31865 input stage is described as protected against overvoltage faults up to 45 V, and it includes programmable fault detection for open and short RTD/cable conditions—useful for commissioning, maintenance, and higher system uptime.

RAKwireless offers the module with a PT100 sensor or as the module only, so you can use your own preferred RTD probes and mechanical form factors.

Typical applications include:

Industrial equipment: process and enclosure temperature monitoring

Instrumentation: test benches, data acquisition, and logging setups

Medical equipment (non-life-critical subsystems): temperature measurement points (validate per device requirements)