Laird BL654 User Manual page 29
Hide thumbs
Also See for BL654:
- Application note (15 pages) ,
- User manual (11 pages) ,
- Quick start manual (3 pages)
Advertisement
The I2C RTC chip (U16) allows the BL654 I2C interface to be tested. The output of the RTC chip (U16) is on the I2C bus and is
by default connected to the BL654 module via jumpers on J17 and J21.
Table 11: I2C RTC chip BL654 I2C signal mappings
I2C RTC EEPROM (U16)
(U16 pin6) RTC_SCL
(U16 pin5) RTC_SDA
Fitting a jumper on J17 routes the RTC_SCL signal to BL654 SIO_27 and fitting a jumper on J21 routes the RTC_SDA to BL654
SIO_26.
10pF,50V
C61
GND
Y 2
32.768KHz,20ppm,7pF
C62
R81
0R
10pF,50V
GND
GND
Figure 15: I2C device RTC chip schematic and PCB
To test the BL654 I2C interface, use smartBASIC application rtcs.erver.sb in the GitHub smartBASIC sample application
repository on the BL654 product page at
BL654 and can be used with an Android phone (requires an app such as nRF connect,
https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp&hl=en_GB) or another
BT900/BL620/BL652/BL654 loaded with "rtcc.lient.sb".
The smartBASIC application "rtcs.erver.sb" is a BLE RTC server, and it advertises the current time (which it gets from the I2C
RTC chip (U4)).
www.lairdtech.com/bluetooth
BL654 module (U5) SIO
(U5 pin38) SIO_27
(U5 pin36) SIO_26
VDD_nRF_SW
R106
0R
0.1uF,16V
GND
C60
R82
U16
10K
1
8
X1
VCC
2
7
X2
MFP
3
6
VBAT
SCL
4
5
VSS
SDA
I2C RTCC,1.8V~5.5V
GND
https://github.com/LairdCP/BL654-Applications.
© Copyright 2018 Laird. All Rights Reserved
Comments
Fit jumper on J17 to route
Fit jumper on J21 to route
NOPOP (TH_TEST_POINT)
TP9
R32
R33
10K
10K
RTC_ALARM
0R
R107
RTC_SCL
RTC_SDA
0R
R108
29
PIN HEADER,2.54mm 1X2P
J17
2
1
2
1
SIO_27
SIO_26
2
1
2
1
J21
PIN HEADER,2.54mm 1X2P
This application runs on the
Americas: +1-800-492-2320
Europe: +44-1628-858-940
Hong Kong: +852 2923 0610
Advertisement
