Nordic-powered interactive teaching aid enables students to answer questions via handheld device

Four Chargtron RAFTs using nRF52810 SoC

The Chargtron Real-time Assessment Frequency Transmitter employs Nordic’s nRF52810 SoC to relay student responses to gateway for teacher analysis via Cloud-based platform

A handheld device used by students to answer test questions, record their attendance, answer surveys, and provide class feedback has been launched by India-based technology company Chargtron IoT. The ‘Real-time Assessment Frequency Transmitter (RAFT)’ employs Nordic’s nRF52810 Bluetooth® Low Energy (Bluetooth LE) multiprotocol System-on-Chip (SoC) to provide the wireless connectivity between the device and an ‘RF Receiver’, which in turn relays the data to the Cloud for review by the teacher either during or after class. 

RAFTs allow teachers to capture student assessment data and receive a detailed breakdown of student performance via the ‘READ ANALYTICS’ web-based dashboard. In operation, each student is issued with a RAFT device—which includes 11 different buttons—that enables them to answer multiple choice questions, provide yes or no answers, ‘virtually’ raise their hand, or rate the learning experience, for example. 

Low latency 2.4 GHz connectivity

Responses are relayed to the RF Receiver in near ‘real time’ thanks to the Nordic SoC’s low latency (<10ms) 2.4 GHz proprietary connectivity, and then to the Cloud, where from the dashboard teachers can compile student test scores, keep track of attendance, as well as develop classroom sessions. When used in remote learning applications, the device employs Bluetooth LE wireless connectivity to connect with the RAFT app on a student’s smartphone. The nRF52810 SoC’s 64 MHz, 32-bit Arm® Cortex® M4 processor, also provides ample processing power to supervise the device’s computational requirements.
We valued Nordic’s reputation for reliability and proven track record
Radhakishan Rao Bompelli, Chargtron IoT

Extended battery life

Each RAFT device is powered by two AAA batteries which provide more than 12 months battery life between replacement, thanks in part to the ultra low power characteristics of the Nordic SoC. The nRF52810 has been engineered to minimize power consumption with features such as the 2.4 GHz radio’s 4.6 mA peak RX/TX currents and a fully-automatic power management system that reduces power consumption by up to 80 percent compared with Nordic’s previous generation of SoCs. 

The nRF52810 combines the Arm processor, with a 2.4 GHz multiprotocol radio (supporting Bluetooth 5.3, ANT™ and proprietary 2.4 GHz RF protocol software) with 192 KB Flash memory and 24 KB RAM. The nRF Connect SDK [Software Development Kit] integrates the Zephyr RTOS, supports applications using Bluetooth LE, Bluetooth mesh and Thread, and is recommended for nRF52810 software development. 

“We selected the nRF52810 SoC because of its low power consumption and because it wouldn’t require frequent replacement of batteries,” says Radhakishan Rao Bompelli, Director, Chargtron IoT. “Moreover, we valued Nordic’s reputation for reliability and proven track record.”