Flyswatter2 LPC2148 How To
Connecting the Flyswatter2 and the LPC2148 board
To hook up the Flyswatter2 and the LPC2148 board, you will need:
- Olimex LPC-P2148 Prototype Board
- 9V DC Power Adapter
- 20-pin JTAG Ribbon Cable
- RS-232 Serial Cable with one male, one female connector
- USB Male A/Male B cable
Connect the RS-232 Cable to the Flyswatter2.
Connect the Other End of the Ribbon Cable to the LPC2148 board.
Connect the JTAG Cable.
Connect the USB cable to the Flyswatter2.
Connect the Power Adapter to the LPC2148 board.
Plug the Power Adapter into a Wall Outlet.
The red LED next to the LPC2148 board's power supply should come on and remain on.
Plug the USB Cable into your PC.
The green power LED on the Flyswatter2 should come on and remain on.
OpenOCD (Open On-Chip Debugger) is open-source software that interfaces with the Flyswatter2. OpenOCD provides debugging and in-system programming for embedded target devices. You will need to compile OpenOCD from source, and patch the source with one of the OpenOCD Patches for Flyswatter 2 support.
Whichever guide you use, be sure to install the patch! Both guides include instructions on downloading and installing the patch.
The first set of instructions uses libFTDI, an open-source driver library for FTDI devices. The second set uses FTD2XX, a closed-source driver library from Future Technology Devices International.
Now you are ready to run OpenOCD. If you installed the OpenOCD Ubuntu package, open a terminal window and type the following from any directory:
openocd -f interface/flyswatter2.cfg -f board/olimex_lpc_h2148.cfg
If you compiled OpenOCD yourself, navigate to the openocd-bin directory you created in the compile guide and type:
cd ~/openocd-bin sudo ./openocd -f interface/flyswatter2.cfg -f board/olimex_lpc_h2148.cfg
For general information on running OpenOCD, see Running OpenOCD on Linux. When you start OpenOCD, you should see this:
You should also hear a high-pitched beep from the buzzer on the LPC2148 board.
You cannot enter commands directly to OpenOCD. Open a new terminal window and type:
telnet localhost 4444
You will should see this prompt:
You can give commands to OpenOCD through this prompt.
Common OpenOCD Commands
To see a full list of OpenOCD commands, enter help in the telnet window.
Resets the LPC2148 board. The output of the Reset command should look like this:
You should also hear a high-pitched beep from the board's buzzer.
Notice the two warnings about slow performance. If you want to speed up the board, you can enable fast memory access and DCC downloads by entering:
> arm7_9 fast_memory_access enable > arm7_9 dcc_downloads enable
With fast memory access and DCC downloads enabled, you should be able to reset the board with no warnings:
Sends a halt request to the LPC2148 board. If the LPC2148 board halts, you will see text output in the telnet window. (If the LPC2148 board is already halted, you will see no output.)
You can also use halt followed by a time in milliseconds. OpenOCD waits for the target to halt the specified amount of time, then gives up if the target has not halted. You can use this to avoid OpenOCD hanging because the LPC2148 board fails to halt. For example, to send a halt command with a timeout of one second, type:
Enter resume to end a halt. You will not see any text output in the telnet window.
Displays a numbered list of all of the LPC2148 board's registers.
Run reg with a register number to display the contents of a register, in hexadecimal. The register number corresponds to the output of the reg command with no arguments, above. You must run the halt command before reading registers.
If you run reg while the LPC2148 board is not halted, you will still see the value stored in the register. However, registers change contents very quickly while the device is running; by the time you see the value, the value actually in the register may be different. If you try to run reg while the device is not halted, you will see this:
reg [entry] [value]
Sets the value of a register. The register number corresponds to the output of the reg command with no arguments, above. Make sure the LPC2148 board is halted (with the halt command) before you change the value of a register!
You can enter registry values in either decimal, by typing a number by itself, or in hexadecimal, by prefacing the value with 0x.
GDB, the GNU Project Debugger is a debugging tool provided with the GNU Compiler Collection (GCC). GDB allows you to stop and start a running program, examine its functioning, and make changes. GDB is installed on Ubuntu 10.04 by default, but you will need a different version of GDB build for embedded targets. Follow the instructions on the GDB Debugger page below.
The GDB debugger page will walk you through installing GDB for use with OpenOCD, and loading and testing a simple program.