Wiring your BX24If you don't have the development board, then you'll have to wire your BX24 up your self. Don't worry, it's not very hard to do.
The first thing to do is go get a 24 pin socket for your BX24. These pins are a little too big for the holes in a protoboard, and IF you get it inserted, you'll break pins off getting it out, plus you'll probably damage the contacts in the protoboard--and if you break a pin off, you'll probably cook something on the chip trying to solder it back on. Trust me, it's worth the 36 cents for a socket, plus, you'll have the socket if you solder this onto a PCB later. As far as a serial port, if you're soldering this onto a PCB, the easiest thing to do is just get a DB9-Female solderable connector. If you're using a protoboard, you can either buy a serial cable, lop off one end of it, tin the wires and insert them into the protobard, OR buy a DB9-Make connector and housing, solder wires onto the pins, and plug them into the protobard. The second suggestion is probably easier because the wires in a serial cable are extrememly small. Whatever you do, you have to remember that the pins are numbered backwards from when you are looking at a Male connector than when you are looking at a Female connector.
Also, the development board I have ties pins 6 and 7 or the serial connection together. Those pins are DSR and RTS, and has something to do with getting the UART on the host machine to send data. Also, don't forget to ground the housing of your connector if you are soldering it onto a PCB. Hook pins 2, 3, 4, and 5 from the serial port to pins 1, 2, 3, and 4 of the BX. Connecting Power As you can see from the BX24 pinout above, you have two options for power, but one of them is a bad idea. You can connect 5.7 up to 15 volts to pin 24, which is a regulator, and it puts out 5V (100mA MAX) to pin 21. The BX24 uses between 17mA and 25mA, so you are free to power other things from pin 21 if you like, BUT if you pull more than 100mA through the regulator, you'll burn it up and the whole chip stops working and you're out $50. Plus, the regulator isn't a very good regulator--the input has to be fairly well regulated to start with. You are better off just connecting a 5V regulated supply that can source at least 100mA to pin 21 (I'll put up a small, cheap powerline regulator circuit somewhere on this site if you are looking ot make something self contained). You're done. Once you have the software installed, loadup an example program (preferable one of the LED demos) and upload it to the chip, but NOT BEFORE you read the notes about using your BX24. There is some stuff you NEED to know in there before you send any program to the chip. This page created by: CJ Oster and Joe Ngai Last Modified: April 28, 2003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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