2

Author Topic: ARM7 question  (Read 4643 times)

0 Members and 1 Guest are viewing this topic.

Offline santiagoeTopic starter

  • Jr. Member
  • **
  • Posts: 15
  • Helpful? 0
ARM7 question
« on: April 20, 2007, 05:27:50 PM »
1st, i woul like to ask ya which one of the following two microcontrollers do ya think is the best and that i should buy along with Dev. board for it?

a) www.futurlec.com/ET-ARM_Stamp.shtml    (LPC2119 Micorocontroller)
This is the Dev board for it: http://www.futurlec.com/ET-ARM_Stamp_Board.shtml

b) www.embeddedartists.com/products/boards/lpc2106.php  (Philips ARM7TDMI LPC2106 microcontroller;LPC2106 QuickStart Board ).
This is the quick start Dev board for it: http://www.embeddedartists.com/products/boards/prototype.php


2nd, i have currently a 4 wheel robot setup: 4 gear motors taken from a two jeeps that is sold in walmart for kids up to 100lbs can ride), 4 hb-25 motor controllers---one for each motor.

2 ultra sonic range finders from parallax

INfrared setup ( one receiver and two emmiters).

i'm using a basic stamp 2.

But know i want to move up the food chaine and use a better more hip ucontroller and so i chose the ARM7. but i will also be using the avr128 aswell in the future.

I want to upgrade my robot by using a camera and wireless connection. I want to avoid obstacles not just with infrared and ultronsonic range sonars but also with vision. That's why i want to use a better ucontroller.

but i dont know if anyone knows how to write a program in c to control 2 sonars or more in C language (i
am a c++ novice).

or how to control a servo in the c language

or how to control irled and receiver in c language

I just want to ask ya if ya do know this if ya would help me ?

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: ARM7 question
« Reply #1 on: April 20, 2007, 05:50:37 PM »
I am very familiar with the Embedded Artists LPC2106 board.  I haven't used the Futurlec boards, but that LPC2129 board is a really good deal.

Some things to consider -

1.  the LPC2129 only has 16kb ram, so you won't be able to do any onboard image processing with a camera interface.  the LPC2106 has 64kb ram, and we do use it for image processing.  however, if you are using a CMUcam, you don't need much memory, so the LPC2119 will be okay

2.  the LPC2129 has some a/d channels which are useful for some sensors (e.g. compass, temperature, accelerometer, etc).  the LPC2106 has no a/d - this hasn't been an issue, though occasionally it would be nice to have it

3.  the LPC2106 has 6 PWM channels, but 2 of those channels are shared with UART0 and the other 2 with UART1.  so if you are using both UARTs (we do), you are left with only 2 PWM channels.  If 2 channels can be used to control 4 motors, then you are in good shape.  Alternatively, if you have an electronic speed controller that takes 2 servo inputs to control 4 motors, that will likewise work.  I don't know for certain, but imagine that the LPC2119 is set up the same way

So bottom line is that either microcontroller is probably a good choice, and the development boards are cheap plus they will probably save you some time.

Surveyor Corporation
  www.surveyor.com

Offline santiagoeTopic starter

  • Jr. Member
  • **
  • Posts: 15
  • Helpful? 0
Re: ARM7 question
« Reply #2 on: April 20, 2007, 06:21:22 PM »
the hb-25 motor controll is connected to a ucontroller and controlled just like a servo. So i want need to worry about how many pwm and how many are left. right? i mean i think on the basic stamp2 i just connect the motor controllers to 4 pins 12,13,14,and 15 thats it (one for signal is the one that connects to ucontroller and than the other 2 or ground and voltage. i m thinking that connecting 4 motor controllers want be a problem right. because i want to also connect a total of 4 or 6 sonars camera torrent , chip with sound and speech (for sound and speech recognition) and more sensors o and wireless. Will i have a problem.

Offline santiagoeTopic starter

  • Jr. Member
  • **
  • Posts: 15
  • Helpful? 0
Re: ARM7 question
« Reply #3 on: April 21, 2007, 01:11:33 AM »
If any one can further elaborate on this subject i will appreciate it.

By the way if ya had the option to connect a CMUcam 2 or CMUcam3 which one would ya choose?

I mean for vision navigation and recognition. I want to use either one of this with the ARM7 2106 or LPC2119.

and would anyone one know how to connect them to a ARM7 ?

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: ARM7 question
« Reply #4 on: April 21, 2007, 08:55:10 AM »
I haven't used CMUcam or AVRcam, but believe they interface through one of the ARM7 uarts.  Likewise, I'm not familiary with your motor controller, but it sounds like it just needs 2 PWM channels, so either LPC2106 or LPC2119 should work for you.

Surveyor Corporation
  www.surveyor.com

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,663
  • Helpful? 169
    • Society of Robots
Re: ARM7 question
« Reply #5 on: April 21, 2007, 03:30:42 PM »
Quote
1st, i woul like to ask ya which one of the following two microcontrollers do ya think is the best and that i should buy along with Dev. board for it?

a) www.futurlec.com/ET-ARM_Stamp.shtml    (LPC2119 Micorocontroller)
This is the Dev board for it: http://www.futurlec.com/ET-ARM_Stamp_Board.shtml

b) www.embeddedartists.com/products/boards/lpc2106.php  (Philips ARM7TDMI LPC2106 microcontroller;LPC2106 QuickStart Board ).
This is the quick start Dev board for it: http://www.embeddedartists.com/products/boards/prototype.php

Although I havent used either, Id say the ET-ARM is better because its half the price and comes with more features (buttons, pins, etc). Oh and you dont really need the development board unless you really think they will save you time/money when you experiment. But I dont like boards that dont have built in power busses, so annoying . . . :-\

Quote
I want to avoid obstacles not just with infrared and ultronsonic range sonars but also with vision. That's why i want to use a better ucontroller.

If you want to do effective obstacle avoidance with vision, you will need a laptop not a microcontroller :P

Quote
the LPC2129 has some a/d channels which are useful for some sensors (e.g. compass, temperature, accelerometer, etc).  the LPC2106 has no a/d - this hasn't been an issue, though occasionally it would be nice to have it

no such thing as too many a/d channels :P

Quote
the hb-25 motor controll is connected to a ucontroller and controlled just like a servo. So i want need to worry about how many pwm and how many are left. right? i mean i think on the basic stamp2 i just connect the motor controllers to 4 pins 12,13,14,and 15 thats it (one for signal is the one that connects to ucontroller and than the other 2 or ground and voltage. i m thinking that connecting 4 motor controllers want be a problem right.

you dont want to use a pwm channel if those motors are controlled like a servo . . . servos are pulse width dependent, but motors also care about how often you send that pulse. if your hb-25 motor can be controlled like a servo, you want to use a D/O pin . . . otherwise use a PWM pin (hope that didnt confuse you!)

anyway, here is my servo code for PIC:
http://www.societyofrobots.com/downloads/stampy_sumo_source_code.zip

and atmel:
http://www.societyofrobots.com/downloads/sbs_source_photovore_v1.zip

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: ARM7 question
« Reply #6 on: April 21, 2007, 04:27:58 PM »
Quote
you dont want to use a pwm channel if those motors are controlled like a servo . . . servos are pulse width dependent, but motors also care about how often you send that pulse. if your hb-25 motor can be controlled like a servo, you want to use a D/O pin . . . otherwise use a PWM pin (hope that didnt confuse you!)

The ARM7 PWM channels can be configured to drive servos.
Surveyor Corporation
  www.surveyor.com

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,663
  • Helpful? 169
    • Society of Robots
Re: ARM7 question
« Reply #7 on: April 21, 2007, 04:35:45 PM »
Quote
The ARM7 PWM channels can be configured to drive servos.
oops ok I stand corrected :P

Offline santiagoeTopic starter

  • Jr. Member
  • **
  • Posts: 15
  • Helpful? 0
Re: ARM7 question
« Reply #8 on: April 21, 2007, 10:33:42 PM »
Admin, you said i need a laptop to do good vision avoidance, but if i get the UMCcam2 or 3 along with the ARM7, want i be able to do object avoidance and navigation. Maybe not mapping and recognition, but avoidanace with the roborealm software right.

O and last but not least, is it possible to connect more than one ARM7 together and how is that possible?


Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,663
  • Helpful? 169
    • Society of Robots
Re: ARM7 question
« Reply #9 on: April 21, 2007, 11:03:50 PM »
Quote
Admin, you said i need a laptop to do good vision avoidance, but if i get the UMCcam2 or 3 along with the ARM7, want i be able to do object avoidance and navigation. Maybe not mapping and recognition, but avoidanace with the roborealm software right.
Avoidance requires your software to calculate 3D distances using 2D images - a difficult task even for experts! Realworld object recognition is also very very very hard (emphasis on hard). I dont recommend either if you have never done any basic vision before . . .
If your goal is object avoidance, there are much easier (yet still as effective) sensors to work with such as sonar or sharp IR . . .

Quote
O and last but not least, is it possible to connect more than one ARM7 together and how is that possible?
Yeap its possible, and there are multiple ways of doing it - serial, uart, D/O, and other indirect means. What information do you want to to share between both?

Offline santiagoeTopic starter

  • Jr. Member
  • **
  • Posts: 15
  • Helpful? 0
Re: ARM7 question
« Reply #10 on: April 22, 2007, 01:29:26 PM »
ADMIN: What do you mean by basic vision?


Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,663
  • Helpful? 169
    • Society of Robots
Re: ARM7 question
« Reply #11 on: April 22, 2007, 02:21:09 PM »
Quote
What do you mean by basic vision?

middle mass detection, determining shape of objects, determining size of objects, counting pixels of different colors, etc.

My computer vision tutorial only goes over the basics - if you havent done those successfully yet, dont even bother with the advanced stuff :P
http://www.societyofrobots.com/programming_computer_vision_tutorial.shtml

Offline santiagoeTopic starter

  • Jr. Member
  • **
  • Posts: 15
  • Helpful? 0
Re: ARM7 question
« Reply #12 on: April 23, 2007, 03:17:03 PM »
Well, i guess we have a misunderstanding ADMIN, I dont want to do any ADVANCED Video navigation. I want to now  add a camera to my robot to do  Basic Navigation. I mean they are teaching that to JR high and High School students who have less experience and education then i do. So I know i can do it.

I been working with microcontrollers, no pics yet and i have integrated into my robot ultra sonic sonars, IrLed, Photoresisters for object avoidance; but now i want to add to my setup a camera for basic navigation and avoidance.

All I want to do is learn how to do this. I will learn by doing not just by reading. That is why i have been asking all this question ADMIN. I have read enougpgh now it's time to get to work. I think i'am going to buy the ARM7 and UMCcam 2 or 3 to do the basic video avoidance and navigation. Just the basic and from that i will move on the  the more advance.

I chose the ARM7 because the people in this forum spoke highly of thie ucontroller and it will look good on my resume.


I will start with your Basic vision Tuturials.

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,663
  • Helpful? 169
    • Society of Robots
Re: ARM7 question
« Reply #13 on: April 23, 2007, 04:48:00 PM »
what I was implying is that navigation with a camera is by default advanced :P

(the exception to this is if you have an oversimplified world, such as a white line to follow or colored beacons for location)

 


Get Your Ad Here