Laird 455-00022, User Manual

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Figure 13: Open solder-bridges on the UART interface running from Atmel MCU (U4) to analog switch U15 (to
BL654PA ultimately)
On the development board, the USB_DTR output (FTDI chip U10) from the PC is wired to BL654PA module pin SIO_35
(pin 5) which is the nAutoRUN pin.
Note: smart BASIC runtime engine FW checks for the status of nAutoRUN during power-up or reset. The nAutoRUN pin
detects if the BL654PA module should power up into Interactive/Development Mode (3.3 V) or Self-contained Run
mode (0V). The module enters Self-contained Run mode if the nAutoRUN pin is at 0V and an application called
$autorun$ exists in the module
’s file system; then the
smart BASIC runtime engine FW executes the smart BASIC
application script automatically; hence the name Self-contained Run mode.
Tying nAutoRUN HIGH (to net name on devboard VDD_VSRC_nRF) inhibits the $autorun$ application from running. As an
alternative to using USB_DTR, the J12 three-pin header allows a jumper to be fitted to select between the two operating
modes.
Table 5: BL654PA nAutoRUN header
nAutoRUN
Pin
BL654PA Operating Mode (pin28, nAutoRUN Mode/SIO_35)
Interactive/
Development Mode
(SIO_35 set High
Externally)
Self-contained Run
Mode (nAutoRUN mode)
(SIO_35 Low Internally)
Circuit
J12
Jumper
Position
Develop
Jumper on J12 pins 2-1
nAutoRUN (default)
Jumper on J12 pins 2-3
BL654PA has internal pull-
down enabled, jumper in
J12 in 2-3 can also be left
off
The J12 header connector allows the USB_DTR signal from the FTDI chip to be disconnected from the BL654PA.
To connect the BL654PA nAutoRUN pin SIO_35 (pin 5) to PC FTDI USB_DTR line via the J12 header connector, do the
following:
▪
Fit the jumper into the J12 (pin 2-1) header connector to allow the PC (using UwTerminal) to control nAutoRUN pin
(SIO_35).
To disconnect the BL654PA nAutoRUN SIO_35 (pin 5) from the PC FTDI USB_DTR line, do the following:
▪
Remove the jumper on header connector J12 pin 2-1. Then nAutoRUN can be controlled by inserting the jumper onto
J12 (pin 2-3) as shown in
Table 5 (this is the default). The BL654PA by default has pull-down enabled on the SIO_35
(nAutoRUN) pin, so the jumper into J12 (pin 2-3) is optional.
IMCU_RTS_A
IMCU_RxD_A
SB19 NOPOP (Solderbridge_Open)
1
1
2
2
IMCU_TxD_A
IMCU_RTS
IMCU_CTS
IMCU_TxD
IMCU_RxD
SB16 NOPOP (Solderbridge_Open)
1
1
2
2
IMCU_CTS_A
SB17 NOPOP (Solderbridge_Open)
1
1
2
2
SB18 NOPOP (Solderbridge_Open)
1
1
2
2
R25
NOPOP (10K)
USB_DTR
GND
VDD_VSRC_nRF
PIN HEADER,2.54mm 1X3P
J12
1
1
2
2
3
3
n_Autorun /
module_DSR
Module_DSR
Develop: Jumper J12 pin2-1 (default)
nAUTORUN: Jumper J12 pin2-3
SIO_35