S e n s o r P u c k
8
Rev. 1.0
5. Sensor Puck Hardware Description
5.1. Schematics
Figure 7 shows the block diagram of the puck with debug header MCU, the sensors, and the Bluetooth module.
Figure 7. Block Diagram
Figure 8 shows the power section. The CR2032 battery is used to power most of the ICs. A boost converter is used
to produce 4.1 V which is used to power the LED of the Si1147 so it can be driven at higher current than is possible
with a coin cell battery.
Figure 8. Power Section
Figure 9 shows the EFM32G210 “Gecko” MCU. The 24 MHz clock is only used in active periods. For lower power
consumption, the internal 32 KHz R-C clock is used as much as possible. A special calibration routine is used to
calibrate the 32 KHz clock against the 24 MHz crystal for accuracy in the UART communication speed while in low
power mode.
Debug pins
VMCU
BLE
05-BLE
BLE_TX
BLE_RX
BLE_WAKE
HOST_WAKE
BLE_RESET
TP2
GND
Pulse
03-Pulse
SDA
SCL
INT
LEDs
07-LEDs
RED
GREEN
J2
HEADER 2x5/SM
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
MCU
02-MCU
BLE_WAKE
RESET
I2C0_SDA
I2C0_SCL
LEU0_TX
LEU0_RX
SWDIO PF1
SWCLK PF0
SWO PF2
INT
RED
GREEN
HOST_WAKE
BLE_RESET
RHT
04-RHT
SDA
SCL
high = 4.1V low = 5.0V
Debug
VMCU
+5V
C11
0.1uF
C12
47uF
U4
TS3310
S1
4
STORE
9
S0
2
VGOOD
6
OUT_ON
1
LSW
8
IN
3
OUT
10
S2
5
EPAD
11
GN
D
7
L1
47uH
SW1
SW_SLIDE_2POS
1
2
3
C13
47uF
R11
47
BH1
20mm BATTERY HOLDER
POS
1
POS
3
NEG
2
