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Example 7 - Energy Harvesting

An example showing how to enable the ST25DV's energy harvesting feature using the SparkFun ST25DV64KC Arduino Library.

Key Features

  • Enabling energy harvesting

Energy Harvesting

The ST25DV can harvest small amounts of power when an RF field is present.

Only small amounts of power can be generated. Perhaps enough to charge a small super capacitor to power a very low-power microcontroller.

By default, energy harvesting is "on demand only" (when the EH_EN bit is set). If the power is removed, harvesting is automatically disabled.

It is possible to configure the tag so energy harvesting is always enabled after boot (if possible) by setting the EH_MODE bit.

Enable EH

To enable energy harvesting, Example 7 opens a security session and then sets the EH_EN bit. A voltage is then produced on the EH breakout pin whenever an RF field is present.

  tag.setEH_CTRL_DYNBit(BIT_EH_CTRL_DYN_EH_EN, true);


The voltage on the EH pin could be higher than 3.3V. Take care if you are using a microcontroller analog pin to measure the voltage.