Walter measures 24.80 x 55 millimeters with 2.54 mm GPIO pins on its long sides. One of the short edges is the ESP's Wi-Fi/BT antenna with a SIM socket on the backside. The other short edge has a USB-C and external antenna connector. Two large packages take up most of the circuit board: ESP32-S3 SoC and GM02SP.
The ESP32-S3 SoC provides a dual-core Xtensa LX7, 2 megabytes PSRAM, 16 megabytes flash memory, Wi-Fi, and Bluetooth 5.
A Monarch GM02SP module from Sequans contains radios for global navigation satellite systems (GNSS) and cellular networks with a single system-on-a-module (SoM). It provides Walter's LTE and GPS connectivity. While the ESP module's antenna works with Wi-Fi and Bluetooth, you need to connect an external antenna for the cellular and positioning radios in the GM02SP module.
This board targets the IoT market. So, it takes power consumption seriously. First, it supports the ESP32-S3's various sleep modes. Additionally, Walter can also control peripheral devices with a software-controllable MOSFET. This switch makes it possible to turn off external devices such as sensors.
There are three pricing tiers planned with preliminary pricing. The entry-level is 49.95 EUR for a bare module. The mid-tier includes antennas for 69.95 EUR. And a developer tier runs 250 EUR. It consists of a pre-paid SIM and engineering support from DPTechnics.
DPTechnics says that Walter's design is open source. However, design files have yet to be made available.