User Manual

5.2 RF
mikromedia 5 offers communication over the world-wide ISM radio band.
The ISM band covers a frequency range between 2.4GHz and 2.4835GHz.
This frequency band is reserved for industrial, scientific, and medical use
(hence the ISM abbreviation). In addition, it is globally available, making it
a perfect alternative to WiFi, when the M2M communication over a short
distance is required.
mikromedia 5 uses the nRF24L01+ (1), a single-chip 2.4GHz transceiver
with an embedded baseband protocol engine, produced by Nordic
Semiconductors. It is a perfect solution for ultra-low power wireless
applications. This transceiver relies on the GFSK modulation, allowing data
rates in the range from 250 kbps, up to 2 Mbps. The GFSK modulation
is the most efficient RF signal modulation scheme, reducing the required
bandwidth, thus wasting less power. The nRF24L01+ also features a
proprietary Enhanced ShockBurst
, a packet-based data link layer.
Besides other functionalities, it offers a 6-channel MultiCeiver
feature,
which allows using the nRF24L01+ in a star network topology. The
nRF24L01+ uses the SPI interface to communicate with the host MCU.
Along the SPI lines, it uses additional GPIO pins for the SPI Chip Select,
Chip Enable, and for the interrupt. The RF section of the mikromedia 5
also features a small chip antenna (4), reducing the need for additional
hardware components.
31 24
P A G E 20
CONNECTIVITY
mikromedia 5 for STM32 CAPACITIVE U S E R M A N U A L