Typical Application Circuit; Figure 3. Typical Application Circuit - ST SPLML-868 Preliminary Data Sheet

3.2

Typical application circuit

In a typical application the SP1ML module is connected to a host MCU using a standard
UART, with transmit and receive signals. This is illustrated in the following diagram.

Figure 3. Typical application circuit

Optional Functionality
1. The TXRXLED signal is an active-low open drain output that can be used to drive an
external LED for status indication when data is sent or received.
2. The RTS and CTS signals can be connected to the host UART interface if hardware
flow control is required.
3. The MODE0 signal provides a hardware method for switching between command and
operating modes. The WKUP signal allows the module to be placed into a low power
shutdown mode and woken up again.
4. The BOOTMODE AND RESET signals should be connected if module firmware will
need to be updated over the UART interface.
5. To support custom module firmware, the serial wire debug signals need to be
accessible for programming and debugging.
10/19
VDD
10uF
HOST
TXD
MCU
RXD
RTS
CTS
GPIO
GPIO
GPIO
GPIO
Doc ID TBD Rev 0.8
1
VDD
SP1ML
TXD
MODULE
RXD
RTS
2
CTS
MODE0
3
WKUP
BOOTMODE
4 5
RESET
GND
VDD
TXRXLED
VDD
SWCLK
SWD
SWDIO
HEADER
RESET
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