On Magellan/B21 Modification

There are many annoying and hidden problems in trying to work on these robots yourself, but it is possible. My old research advisor Bruce Maxwell and I modified three Magellans successfully, including replacing the somewhat shaky peripheral power board.

RJ12->DB9F RS232 Adaptor Pinout!

The most useful piece of information I can give you:

How to wire these stupid adaptors. You can't find this information anywhere else online. Trust me, I've looked. I spent a great deal of time testing different pinouts to find this about 2 years ago. Why would you need to use these anyway?

• You've fried the old motherboard on your Magellan (did this)
• You want to upgrade the computer in your Magellan (also this)
• You've fried the RocketPort on your B21 (we did this)
• You want to move to a motherboard without an ISA slot and not have to buy another RocketPort(see notes on this)

By Color:

Black  -> Pin 1
Green  -> Pin 2
Red    -> Pin 3
White  -> Pin 4
Yellow -> Pin 5
Blue   -> Unused

Here's a diagram of how my adaptors (from DigiKey) were set up (most adaptors are probably in this configuration):

     W B R G Y Bl
  |--|-|-|-|-|-|--|
  |               |
  |               |
  \_____     _____/
       |____|

Testing the Serial Connection

On the Magellans, I had luck just running the rFlex serial straight into minicom to get a response in testing. I have not been able to replicate this on the B21 (I'm hoping this doesn't mean we hosed the rFlex..).

Note: I have had difficulty with recent versions of minicom, and better success using gtkterm. If you are having difficulty testing with minicom, don't give up on your rFlex yet-- try testing with the Mage library. Contact me and I can send a copy.

Your best bet is to actually run whatever code you have for talking to the rFlex or other devices. On the B21, I finally determined this was working with our SICK laser.

Notes on USB->Serial Adaptors

I believe that these should work, but I have had difficulty with them. This may have been related entirely to problems with minicom.

We ultimately bought a new PCI RocketPort board. I could not get the driver that ships with the Linux kernel to work, but comtrol's drivers work fine. If you're using a 2.6 kernel, you'll want to acquire the beta driver.

B21 Specific

First off: The power boards on the B21 do not fire up until the computer is on. The power boards on the B21 do not fire up until the rFlex is running. Never forget these two facts, or you will be very confused.

And if you haven't discovered this yourself: Those power boards, for peripherals, and the computers? Miserably flaky. Do not add devices to the board while the power is on-- about half the time they will completely flake out, shutting down the computer and any peripherals you have attached to it.

Magellan Specific

The best advice for Magellans is to replace the peripheral power board. If you upgrade the computer, you don't need most of the voltages it produces, but you will need a lot more from the 5volts. This will tend to burn the board. For plans and part numbers for making a new board (your Vicor must be functional!), contact Bruce Maxwell.