User's Manual
Table Of Contents
- 1 Introduction
- 2 General Product Description
- 3 Application Interface
- 3.1 Power Supply
- 3.2 Reset
- 3.3 Serial Interface
- 3.4 GPIO Interface
- 3.5 I2C Interface 0F
- 3.6 SPI Serial Peripheral Interface
- 3.7 Bluetooth Radio Interface
- 1.1
- 3.8 NFC Function
- 3.9 Slow Clock Interface
- 3.10 Test Mode
- 3.11 Operating in a Power-Switched Environment
- 3.12 Serial Wire Debug Interface
- 3.13 DC/DC Converter
- 4 Module Pins
- 5 Electrical Characteristics
- 6 Mechanical Characteristics
- 7 Application Diagram
- 8 Compliances
- 9 Packing
- 10 Ordering Information
- 11 Safety Recommendations
- 12 Document History
BlueMod+S42 Hardware User Guide
1VV0301303 Rev.3 – 2016-08-22
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights Reserved.
Page 24 of 62
Signal UICP deactivated UICP activated
UART-CTS# I-PD I-FLOAT
IUR-IN# I-DIS I-FLOAT
IUR-OUT# I-DIS O-PP
Legend: I-PD = Input with pull-down resistor, I-DIS = Input disconnected,
I-FLOAT = input floating, O-PP = Output push-pull
Signal types I-PD, I-DIS and O-PP may be left open. I-FLOAT has to be driven to GND or
VCC to avoid open CMOS input oscillation.
If UICP is deactivated the pull-down resistor on UART-CTS# helps to keep the serial
interface active if UART-CTS# is open.
If UICP is active and the serial interface is down, UART-CTS# has to be held at VCC and
thus the pull-down would cause an unwanted permanent current drain. Therefore the pull-
down is switched off in this mode.
3.4 GPIO Interface
It is possible to use the programmable digital I/Os GPIO[0:14] on the BlueMod+S42. Their
behavior has to be defined project specific in the firmware.
Unused GPIO pins shall be left unconnected to stay compatible. There may be functions
assigned to some in future versions of the firmware.
3.5 I
2
C Interface
1
The I
2
C bus interface serves as an interface between the internal microcontroller and the serial
I
2
C bus. BlueMod+S42 is the master and controls all I
2
C bus specific sequencing, protocol
and timing. It supports standard (100kHz) and fast (400kHz) speed modes. The
BlueMod+S42 as an I
2
C master must be the only master of the I
2
C bus (no multimaster
capability). Clock stretching is supported.
GPIO[1]/I2C-SDA and GPIO[0]/I2C-SCL can be used to form an I
2
C interface. It is required
to connect 4k7 pull-up resistors on I2C-SCL and I2C-SDA when this interface is used.
1
subject to firmware support, contact Telit for current status