User Manual

P A G E 25
mikromedia 7 CAPACITIVE U S E R M A N U A L
P A G E 25
mikromedia 7
CAPACITIVE
U S E R M A N U A L
CONNECTIVITY
4 5
5.3 RF
mikromedia 7 offers communication over the world-wide ISM radio
frequency (RF) band. The ISM band covers a frequency range between
2.4GHz and 2.4835GHz. This RF 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 7 uses the nRF24L01+ (4), 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 being more efficient. The nRF24L01+ also features the
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.
Besides 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 7
also features a small chip antenna (5), reducing the need for additional
hardware components.
Figure 13: RF and WiFi sections view
mikromedia 7 CAPACITIVE U S E R M A N U A L