From: One Stone
X-Mailer: Mozilla 4.75 [en] (Win98; U)
Subject: Re: which microcontroller should I choose.
Organization: Chariot Internet - http://www.chariot.net.au
Date: Mon, 25 Nov 2002 05:26:12 +1030
NNTP-Posting-Date: Mon, 25 Nov 2002 05:52:52 EST
Get a small transceiver circuit. For simplicity wire it to your serial
port. You will need to put a MAX232 or similar on the board. I prefer
the St232, as it's 3.3V, like most radios. Invert the Rx and TX lines on
the TTL side of the UART, since RS232 idles high, and you want the
transmitter to idle low. Battery power this, or use a dc/dc switcher
that will convert Rs232 levels into 3V3. You can either hardware switch,
or preferably use RTS to switch between TX and RX modes.
In the Robot have another, similar circuit, except you don't need the
MAX232 driver. Choice of micro is largely irrelevant to the concept. For
simplicity get one with a UART. Now wire the micro up to the sensors
directly, and then just communciate status as necessary. To send real
time video is a bit different, don't pass that through a micro, you
would require a really high speed bus for real time, and that might
complicate things, why not just use a wireless video setup and a cheap
TV tuner in the PC.
You seem to be going round in circles with a lot of similar related
questions. Some here are likely to get ticked off by that and stop
helping you. It would be more beneficial to you to have laid out your
entire problem at the start. Like I want to communicate from my robot to
my PC and back again. I have XY sensors MN switches, and colour video.
If the robot is still in the design stage ask for help with that too. If
you need 32 I/o what mix are they? what analog signals what digital, do
any need critically timed. Once you have the micro in the robot you can
do heaps more with it. I would use an MSP430F149, because I have lots of
them, and they have enough I/O. My young son got the Real Robots
magazine, I think it is of UK origin. Build a simple "robot" a part each
week. 2 wheels/gearboxes, 2 motors, simple sensors and mostly discrete
circuits, ie logic or analog. It is soon to get a whole array of new
capabilites with an MSP micro, including auto-navigation, 'food'
seeking, a hugely upgraded battery, and a truckload of sensors.
David Jones wrote:
> I've been researching microcontrollers but there are just tons and tons. I
> have no idea which to choose. I can program in assembly. I need it to input
> serial info from my computer, output about 32 or slightly more bits in
> parallel and input some video from a homemade robot and send that back to
> the computer. any suggestions?