PDA

View Full Version : BS2 With Printer Port



Mr. Sparkle
01-03-2006, 05:40 AM
Since my primary computer is a laptop, corners were cut as far as serial ports go. Instead of having a 9-pin serial port, I have a 25-pin serial port (the kind you plug a printer into). Today I got a 25-pin female to 9-pin male adapter so I could use an old parallel cable that I found lying around with the Board of Education, but the Editor doesn't recognize it as existing. I'm curious if this has anything to do with the fact that pins 14 and 25 are missing, such that the pinout of the cable looks like this:




_____________________________
\ o o o o o o o o o o o o o /
\ x o o o o o o o o o o x /
-------------------------

o - Pin exists
x - Pin missing



Is it possible at all for me to use a 25-pin cable with the BOE?

allanlane5
01-03-2006, 05:52 AM
1. A 25-pin, female (with sockets) connector on a laptop is NOT a 'serial port', it is a 'parallel port'. It follows a completely different pin-out, and completely different signaling. You cannot convert it into a serial port with a simple DB25 to DB9 adapter.

2. There ARE 25-pin serial port connectors out there. PC's and laptops don't use them.

3. IF you connect a parallel port to the BOE, it's not going to work. The BOE must be connected to a SERIAL port.

4. It is possible to purchase a USB to serial adapter, from FTDI, BAFO, or Keyspan. These are known to work. Belkin USB to serial adapters don't implement all the handshake signals the BOE requires. This is the recommended solution to your problem.

Forrest
01-03-2006, 05:53 AM
First off I think you'll need to identify the port on your laptop. It's very rare to have a 25 pin serial port on a laptop. I'm almost positive the 25 pin D port on your computer is in fact a parallel printer port. If you want to program the BS2, then you can't use the parallel port. You'll need a serial port or a USB port (if you're using a BOE with a USB connector) or a USB to serial converter (which are sometime problematic when running off batteries on a laptop).

Robert Kubichek
01-03-2006, 06:00 AM
Mr. Sparkle said...
Since my primary computer is a laptop, corners were cut as far as serial ports go. Instead of having a 9-pin serial port, I have a 25-pin serial port (the kind you plug a printer into). Today I got a 25-pin female to 9-pin male adapter so I could use an old parallel cable that I found lying around with the Board of Education, but the Editor doesn't recognize it as existing. I'm curious if this has anything to do with the fact that pins 14 and 25 are missing, such that the pinout of the cable looks like this:




_____________________________
\ o o o o o o o o o o o o o /
\ x o o o o o o o o o o x /
-------------------------

o - Pin exists
x - Pin missing



Is it possible at all for me to use a 25-pin cable with the BOE?


Don't use that cable. You need either a 25 pin extension cable (were all pins pass through), or an At serial cable that has reverse pins on ends;
(DB25 female---DB9male, hard to find) or get the regular At serial, and put thin gender changers on both ends (easiest to do)...

Bob N9LVU http://forums.parallax.com/images/smilies/scool.gif

allanlane5
01-03-2006, 06:04 AM
Note the normal connection to a PC or laptop uses a DB-9 male to DB-9 female cable, all pins wired straight through (no swapping pins 2 and 3, etc). The BOE connector was designed for simplicity of connection to a PC's DB-9 connector, with a straight through wired cable.

Note all PC USB to Serial adapters also support this pinout.

Mr. Sparkle
01-03-2006, 07:19 AM
Point taken. I'll just have to use an alternate computer.