BBMICRO:FAQ
From K9spud
BBMICRO is a low cost development board for the LPC2101, LPC2102, and LPC2103 ARM7TDMI-S microcontrollers from Philips.
Are you sure you can really solder this chip by hand?
It's not the easiest thing in the world, but it is doable. The PCB makes it much easier. You will probably get several solder bridges between pins when initially soldering, but don't panic! Those solder bridges can be fixed by using flux to reflow the solder properly:
- No-Clean Flux - Cheap and easy to use, but leaves ugly amber residue.
- Water Soluble Flux - Easy to wash away excess residue, but you have to use water soluble core solder as well (or coreless solder).
It takes some patience, but it does work. If you want, buy a few spare boards and chips to practice on, they don't cost that much.
Where do I get an ARM build environment?
WinARM is an easy to install toolchain for Windows, which includes the free GNU GCC C compiler for ARM, along with several libraries and other tools. Just unzip the archive to c:\winarm and add "c:\winarm\bin;c:\winarm\utils\bin" to your path.
There are also several commercial toolchains available from Keil, Rowley, etc. We don't have any experience with them though.
Where can I get an lpc2103.h header file?
There's a couple of them floating around on the Internet, but they are Copyright by commercial C compiler software companies that wrote them. We've worked on making a copyleft header file for the LPC2103 using the register addresses documented in the LPC2103 User's Manual. It should be pretty complete now:
Does the board support in-circuit debugging?
There are holes in the board for a 10 pin header to provide easy access to all of the processor's JTAG debugging signals. However, we haven't tested this interface yet. It does not conform to the standard 20 pin JTAG header used by most LPC development boards, so it might not work great.
We wanted to try a 10 pin header so that we could cram it into the tiny form factor.
Does the Philips Flash Utility work with USB to serial dongles?
I'm using it with the FT-232 BM chipset serial dongle from Anyla.com and it seems to be working fine!
How come my PC's serial terminal software can't communicate with my firmware?
The BBMICRO uses the RTS and DTR signals to control the LPC2103's RESET and ISP signals, in accordance with the Philips ISP programming software. This is great for programming the firmware.
However, most serial terminal programs assert the DTR signal when they open the serial port. That's great for communicating with a modem, but bad for communicating with your firmware running on the BBMICRO because DTR holds the microcontroller in reset.
The solution is to use a serial terminal program that can correctly control the DTR and RTS signals to work with the BBMICRO. WinARM is packaged with a program called "terminal.exe" that will let you manually toggle the DTR and RTS signals yourself.
What is the J5/ISP jumper useful for?
Nothing really. It was originally included just in case the DTR/RTS serial control circuitry for automatically driving the RESET and ISP signals didn't work. The serial port controls work fine though, so there is really no need for the J5/ISP jumper. We will probably remove it on pre-assembled kits in the future.
The reset button is also not really necessary either, since the PC can control the RESET signal through the serial port's DTR signal.
