Walter is an open source, fully certified (CE, UKCA, FCC, IC, RCM), multi-radio module with cellular (LTE-M, NB-IoT), GNSS (GPS, GLONASS), WiFi and Bluetooth. It is a small-form-factor IoT system-on-module (SoM) that combines a powerful ESP32-S3 system-on-chip (SoC) with a second-generation Sequans GM02SP LTE-M/NB-IoT 5G modem and GNSS receiver. Its ESP32-S3 provides many built-in peripherals as well, including UART, SPI, I²C, CAN, Wi-Fi b/g/n, and Bluetooth 5.
For many battery-powered applications, Walter will spend most of its time in deep sleep. It is therefore critical that we consume as little power as possible in this mode, which was among our key requirements during the design stage. We are extremely proud of the result and have validated that Walter only consumes 9.8 µA in deep sleep mode with PSM, the industries’ lowest for a multi-radio module.
We created Walter for remote sensing and control applications, and we’ve been working hard to perfect it by incorporating feedback from beta testers who’ve given us insights related to various other possible applications, including:
– GPS tracker: As the GNSS receiver is built in, you don’t even need an expansion board to build a global tracking solution with Walter. In fact, as mentioned above, Walter comes pre-flashed with tracking firmware that uploads data to our demonstration platform.
– Remote weather station: When slotted into our carrier board, Walter can monitor various sensors from virtually anywhere. Its 5G connection (LTE-M or NB-IoT) has such good range that you can easily monitor remote locations.
– Tank level sensor: To evaluate Walter’s indoor coverage, we added an ultrasonic sensor that allowed it to determine the level of liquid in a tank. We tested the result at various locations throughout Belgium and were pleasantly surprised by the results, which included a good signal from two stories underground beneath a metal cover.
