SPMB250-A1EVAL View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
SPMB250-A1EVAL
STMicroelectronics
'SPMB250-A1EVAL' PDF : 16 Pages View PDF
UM0562
Firmware description
Figure 7 shows the format of the packet as available at the COM port.
● The “i” and “e” bytes are fixed at 105d and 102d respectively and function as a packet
delimiter.
● NodeID corresponds to the network address of the MotionBee™ modules assigned
during the network joining procedure. In an application running on the PC, this field
makes it possible to distinguish the sender of each packet.
● X, Y, Z are the acceleration values as detected by the sensors in each MotionBee™.
4.2
MotionBee™ firmware
The firmware loaded on the MotionBee™ modules includes the EmberZNet™ 3.0.0 protocol
stack together with a simple application that samples the accelerometer with a fixed
frequency of 33 Hz. The accelerometer data are composed within the packet payload and
then sent to the radio for transmission. On each axis the scale of measured values is set to
± 2 g.
This application has been written only for demonstration purposes and it uses the
accelerometer sensor in a specific configuration. Custom firmware can be developed and
loaded on the modules through the SIF connector, in order to fully exploit all of the sensor
configuration capabilities (please refer to the LIS3LV02DL datasheet and application note
AN2381).
4.3
Forming a network
The procedure to network the dongle and the MotionBee™ is described below. The network
uses channel 26 and PANID 0x01FF fixed values.
1. Connect the dongle to one of the USB slots on the PC. The dongle is powered through
the USB port. Both green and red LEDS turn on. After creating the network, the dongle
starts sending advertisement packets.
2. To connect a MotionBee™ within the network:
a) Turn on the power switch.
b) Push the commissioning button. The green LED turns on.
c) The MotionBee™ initiates the joining procedure and when the association step is
completed, the red LED turns on.
d) The MotionBee™ starts sending packets (every 33 ms) and the green LED blinks
at each transmission.
e) The dongle collects packets sent by the MotionBee™, making them available
through the COM port with the format described above. The red LED blinks each
time it receives a packet.
Up to 4 MotionBee™ modules can be connected to the same dongle without significant loss
of performance.
Doc ID 14826 Rev 2
11/15
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