first time posting to this fourm, this should be an easy question?

Comments

• Mike Green Posts: 23,101

  2006-12-08 20:17 edited 2006-12-08 20:17

  SPIN is pretty easy. There are some unusual features like the use of indenting for statement scope, not hard to get used to. It's truly not very OO, mostly functionality is encapsulated in "objects" which are separate source files. You can have public and private "methods" in an object and named constants are accessable from outside the object.
  
  The chip itself doesn't have any pre-existing connections to the outside world other than a serial (Tx,Rx) port used for initial loading from the IDE and an I2C bus used to connect an EEPROM for another source of an initial download. There are any number of Ethernet interfaces you can buy and connect to the Propeller, but you'll have to write your own interface software unless you're just using a Telnet device as a serial port substitute. The same thing is true if you do the Ethernet connection wirelessly.
  
  The Propeller chip can generate standard NTSC analog broadcast video that can be received on one of the low numbered VHF channels. It doesn't provide any other kind of wireless link without external hardware other than just a few resistors (it just provides standard baseband video or VGA in any of several resolutions). There's no built-in video input and really not enough memory on-chip to do much with it if it were there. Several forum members have been working with image sensors for use in robotics and are doing fairly impressive things, but these use special purpose cameras with reduced resolutions. Some forum members have discussed ideas for attaching dual ported ram with the 2nd port fed directly by a video digitizer. That could work, but there are only 32 I/O pins available and you'd have to be creative about accessing the memory from the Propeller without giving up most of the I/O pins for that purpose.
  
  You can use external ram and EEPROM, but these are not extensions to the internal ram and you have to provide your own software to use parallel ram. There are some existing routines for accessing I2C EEPROM as well as SPI interface memory cards.
• Rontopia Posts: 139

  2006-12-08 20:31 edited 2006-12-08 20:31

  wow thanks..
  
  I guess the video question is not an easy one.. right now, I am building a bot that has an x86 processor that puts off 15watts if I remember right. this gives me the ability to run cams and wifi as well as sensors and motors. but its still overkill. it was cheap tho. the motherboard is 9 x 9 inches or so and cost me 70 bucks. I was actually going to use it in my truck as an MP3/Media player but.. then I got to thinking.. and well you know the rest[noparse]:)[/noparse]
  
  anyway.. I was wondering if a propeller chip or 2 could do the same job.. but it sounds like it might be more money and a lot more work?
  
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• acantostega Posts: 105

  2006-12-09 16:12 edited 2006-12-09 16:12

  I've found SPIN pretty easy. If you have experience with C (specially pointer fiddling) you'll be fine.
  To interface a webcam with a prop would seem pretty hard, for a lot of reasons. The propeller would be better suited to other tasks in a robot, like motor control and interfacing with (lesser bandwidth) sensors.