R
ADIO
B
RIDGE
RBM101
I
U
SER
G
UIDE
C
OPYRIGHT
©
2017,
R
ADIO
B
RIDGE
I
NC
.
R
ADIO
B
RIDGE
RBM101
I
U
SER
G
UIDE
P
AGE
16
OF
19
5.
C
ONFIGURATION
5.1.
Bootloader
The module contains a bootloader to allow for firmware upgrades. The configuration utility
provides an easy to use interface for the bootloader and programming the module with new
firmware images and is recommended above using any terminal emulators or manual
methods of upgrading the image.
5.1.1.
Using Terminal Emulators
When usage of the configuration utility is not possible, the bootloader can also be used
through a simple terminal program such as Tera Term via AT commands or through an
external microcontroller.
If the serial port is connected to a terminal program, the following will be displayed after it
receives the BL AT command:
Press <DEL> to enter Bootloader
The bootloader then waits a period of 3 seconds (by default) for the <DEL> character (ASCII
character 127) and re-enters the program if it is not received. The same prompt appears
anytime the device is reset which allows the user to program a new image even if the current
image has become corrupt.
When running a terminal program, the following is displayed when the bootloader is entered:
Radio Bridge Bootloader v1.0.0
1.
Upload Image
2.
Run Application
3.
Menu
Sending ASCII ‘1’ starts a 60 second timer and provides a window for the new image to be
transferred via XMODEM protocol. The XMODEM protocol is a standard file transfer protocol
and is described in other references. If the firmware image transfers properly the menu will
re-
appear and sending ASCII ‘2’ will re
-enter the main application.
The time that the bootloader waits for the <DEL> input key is configurable through the BT
(Bootloader Timeout) AT command. The maximum wait time is 3 seconds (default) but the
delay can be reduced to reduce the amount of time it takes to enter the main application. If
the bootloader timeout is set to zero, the bootloader is skipped completely at reset and the
main application is entered directly.
As a failsafe measure, there are two pads on the top side of the module with the label
“Bootloader”. If these pads are shorted together during reset, the bootloader will enter
automatically.
