Figure 2.
STEVAL-GPT001V1 kit: smart watch direct access points
The back cover can be removed to access the battery and the STEVAL-GPT001V1 cradle board.
1.1.1.2
STEVAL-GPT001V1 cradle board
The
STEVAL-GPT001V1
cradle board hosts and supplies the STEVAL-STLCS01V1 SensorTile module; it
increases the autonomy of the SensorTile module when the 5 V USB supply source is not available, thanks to the
harvested energy provided by the PV panels.
The cradle board features:
•
A pluggable or solderable interface (CN2) for the STEVAL-STLCS01V1 SensorTile module
•
SPV1050TTR
– high efficiency harvester, battery charger and power manager
•
SW1 - ON/OFF switch to enable/disable the LDO supplying the SensorTile module
•
STBC08PMR
– 800 mA standalone linear Li-Ion battery charger
•
HTS221
– capacitive digital sensor for relative humidity and temperature
•
STC3115
– fuel gauge IC
•
USBLC6-2P6
– very low capacitance ESD protection
•
USB type A to micro-B USB connector for power supply and communication
•
SWD connector for programming and debugging
1.1.1.3
Battery
The battery included in the kit is a one cell (3.7 V) lithium polymer battery able to supply up to 100 mAh (refer to
Section 1.4.5 STEVAL-GPT001V1 programming interface
for instructions on how to connect the battery to the
STEVAL-GPT001V1
cradle board).
1.1.1.4
SWD cable
The five-way SWD cable easily allows the
STEVAL-GPT001V1
cradle board to be connected to a programmer/
debugger system such as ST-LINK V2.1 (refer to
Section 1.4.5 STEVAL-GPT001V1 programming interface
for
further details on the programming interface).
1.2
Software description
The STSW-GPT001V1 software available with the
STEVAL-GPT001V1
development kit is based on the STSW-
STLKT01 SensorTile kit software, with the addition of the following functions:
•
Running mode
, which calculates the system autonomy on the basis of the battery current sensed by
STC3115
through resistor R9. This computation is based on the
STEVAL-STLCS01V1
module average
current consumption when the PV modules constitute the available energy source. The software returns the
battery charge level, the average current consumption and the estimated overall system autonomy.
•
Sleep mode
: the interrupt to wake up the microcontroller is provided by the accelerometer output being
inactive for a time period longer than 1 minute by default. It can be changed and set up according to the
specific firmware needs. In this condition, the RTC of the microcontroller remains active to count the time
elapsed during the low power consumption mode. Battery charge measurement just before and after the
sleep mode allows calculating the amount of charge stored during this time frame.
UM2260
Software description
UM2260
-
Rev 2
page 3/25
