DPTechnic's Walter Cellular IoT Module Family Grows, wIth the Walter Cat 1 Bis

DPTechnics is preparing its second crowdfunding campaign, as its Walter cellular system-on-module family grows by one: meet the Walter Cat 1 Bis.

"Walter Cat 1 bis is a small-form-factor IoT SoM [Internet of Things System-on-Module] that adds support for worldwide LTE Cat 1 bis to the powerful [Espressif] ESP32-S3 SoC [System-on-Chip]," DPTechnics' Daan Pape explains. "On top of the ESP32-S3’s many built-in peripherals — such as UART, SPI, I2C, CAN, Wi-Fi b/g/n, and Bluetooth 5 — Walter also features the Sequans GC02S1 LTE Cat 1 bis modem."

This isn't the first entry in the Walter family: we first saw the original Walter three years ago, combining an Espressif ESP32-S3 microcontroller with a Sequans Monarch GM02SP for cellular connectivity and Global Navigation Satellite System (GNSS) reception. The board launched in crowdfunding on Crowd Supply around a year later, successfully raising almost $70,000 to bring it to production.

The new model sticks with the tried-and-tested system-on-module format, and retains the same Espressif ESP32-S3 microcontroller and Wi-Fi/Bluetooth 5 module. Where it differs is in the cellular side of things, moving from the Monarch GM02SP of the original Walter to the Sequans GC02S1 LTE Cat 1 bis.

The new modem, certified for global use, is based around 3GPP LTE Release 14, providing up to 10Mb/s download and 5Mb/s upload throughput. There's a nano-SIM slot with support for SGP.32 physical SIM cards and pre-SGP.42 eSIMs, and an ultra-low-power deep-sleep mode. Elsewhere on the board are 24 general-purpose input/output (GPIO) pins, any of which can be programmed for UART, SPI, I2C, CAN, I2S, and SD bus connectivity, analog to digital and digital to analog converters (ADC/DAC), and a physical reset button.

"Any IoT application that requires cellular connectivity is a great fit [for the Walter Cat 1 Bis]," Pape claims. "A few examples that become practical and economically viable, even at low volumes, include: asset tracking, vehicle telematics, security systems, payment processing, wearables, smart-city applications, and scientific measurement equipment."

The project is currently awaiting receipt of the global model of the Sequans GC02S1, the GC02S1-WW, having performed initial design and testing on the European variant; once complete, DPTechnics plans to launch a crowdfunding campaign for the board on Crowd Supply. "In the coming months, once our internal testing is complete, we will publish the schematics for Walter Cat 1 bis," Daan promises of his company's commitment to open hardware, "just as we did for the original Walter module."