i.MX8M Nano based mini-PC features Wirepas mesh networking

i.MX8M Nano based mini-PC features Wirepas mesh networking

Sep 22, 2021 — by Eric Brown

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SolidRun’s $221-and-up “SolidSense N8 IoT Compact” mini-PC runs Linux on an i.MX8M Nano Solo with GbE, WiFi/BT, USB, and a choice of LTE or PoE. You also get a choice of RS485 with CAN or BLE 5.0 with Wirepas Massive.

The SolidSense N8 IoT Compact embedded system follows SolidRun’s i.MX6-based SolidSense N6 Edge Gateway, which similarly offers a bundle of the Wirepas wireless mesh software from Tampere, Finland based Wirepas. The wireless mesh software, which is now called Wirepas Massive, is pre-installed along with software defined radios (SDRs) on two of the four i.MX8M Nano based SolidSense N8 models. Applications include IoT tasks such as automation, asset tracking, security, and smart buildings.

SolidSense N8 IoT Compact BLE
(click images to enlarge)

The four models, listed here with key differentiating features, include:

• SolidSense N8 IoT Compact BLE — PoE, BLE 5.0 with or without pre-flashed Wirepas SDR
• SolidSense N8 IoT Compact LTE BLE — LTE Cat4, GPS, BLE 5.0 with or without pre-flashed Wirepas SDR
• SolidSense N8 IoT Compact Extended — PoE, RS485, CAN
• SolidSense N8 IoT Compact Extended LTE — LTE Cat4, GPS, RS485, CAN

Initially only the SolidSense N8 IoT Compact BLE model is available. It sells for $231 with the Wirepas SDR pre-flashed and $221 without. The images above for the BLE SKU show an LTE SMA connector, a SIM slot, and a combined RS485 and CAN port, which suggests that the ports are present on all the models even if, as in this case, they are not activated.

Wirepas Massive uses 2.4GHz radios for mesh networking, implemented here via a Cortex-M4-enabled Nordic nRF52832 Bluetooth Low Energy (BLE) 5.0 SoC. The software extends over backhauled cellular, WiFi, Ethernet, and other communications links.

Wirepas Massive’s decentralized IoT network protocol can be used to connect, locate, and identify lights, sensors, beacons, assets, machines, and meters. The software enhances wireless throughput via automatic multi-gateway and load-balancing support, thereby enabling large mesh networks with massive data requirements. The SolidSense N8 cloud service supporting Wirepas is available as a Platform as a Service (PaaS) or can be deployed on customer IT infrastructures.

SolidSense N8 block diagram (left) and an architecture diagram for SolidRun’s implementation of Wirepas Massive
(click images to enlarge)

The SolidSense N8 IoT Compact uses the rarely seen single-core Solo version of the i.MX8M Nano, the lowest powered, but still up to quad-core, Cortex-A53 based member of the i.MX8 family. Clocked here at 1.5GHz, the SoC lacks a VPU, but offers a 650MHz Cortex-M7 chip.

The SolidSense N8 IoT Compact supports Debian by default in a stack that includes U-Boot with Mender OTA, remote control, and optional Wirepass Massive 4.0 support. There is also a barebones option of the Debian stack with U-Boot only. Instructions show how to build your own stack with Yocto and BuildRoot, and OpenWrt is also supported.

All the SolidSense N8 models are equipped with 1GB DDR4, 8GB eMMC, and a microSD slot. Other standard features include Gigabit Ethernet and USB 2.0 ports plus an internal console debug port. An internal expansion header offers USB and multiple UART, SPI, and I2C signals (see block diagram above).

SolidSense N8 mainboard detail views, front and back
(click images to enlarge)

All the systems offer a standard 802.11ac/Bluetooth 4.0 module in addition to the optional BLE/Wirepas and LTE/GPS radios. Wireless features include a SIM card slot, an internal WiFi/BT antenna, an internal GPS antenna for the U-Blox Nina chip, and an SMA connector and optional external antenna for LTE. The LTE radio connects via a USB 2.0 hub, as opposed to mini-PCIe on the still available N6 series. The block diagram suggests you can swap out LTE Cat4 for LTE Cat1 via an assembly option.

The SolidSense N8 IoT Compact has a 9-36V DC input with Supercap backup, a battery charger, and an optional 12V adapter. Other features include an RTC with battery, programmable LEDs, and power, reset, and boot switches.

The fanless device lacks the IP65 protection and extended temperature range of the outdoor model of the N6. The 150 x 85 x 40mm system is smaller than the N6 outdoor model but larger than the indoor model. The system has a 0 to 50°C operating range and a plastic casing.

Further information

The SolidSense N8 IoT Compact BLE sells for $231 with the Wirepas SDR pre-flashed and $221 without, both with an 8-week lead time. No pricing or availability information was provided for the other models. More information may be found in SolidRun’s Compact BLE shopping page and SolidSense N8 product page.