Post by thread:[PIC]: PIC16F877

hi all, I have successfully build an autonomous mobile wheeled robot using PIC16F877 (2 wheeled). I have IR sensors all around the robot for obstacle detection and I have some below for table top edge detection (so that it will not fall off a table). I have also ultrasonic sensors at strategic locations to double up as obstacle detection device, in case the IR sensors failed to detect. I also have contact sensors all around to act as final backups. I have the desire to add some function or features to my robot. Can anyone suggest any to me?? Regards, Henry -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Henry Low wrote: > > hi all, > I have successfully build an autonomous mobile wheeled robot using > PIC16F877 (2 wheeled). I have IR sensors all around the robot for obstacle > detection and I have some below for table top edge detection (so that it > will not fall off a table). I have also ultrasonic sensors at strategic > locations to double up as obstacle detection device, in case the IR sensors > failed to detect. I also have contact sensors all around to act as final > backups. > I have the desire to add some function or features to my robot. Can > anyone suggest any to me?? > > Regards, > Henry Add some sort of navigation capability, such as a compass, is a start. This could improve the navigation scheme that you use now, which I'm guessing is dead-reckoning. The Precision Navigation Vector2x <http://www.precisionnav.com/vector2xmain.html> is a reasonably priced device, there are better compasses, but they generally cost a great deal more. There was a good program out there that hooked up a Vector compass and an LCD module with a 16F84. I adapted it to my own use, but I can't seem to find it anymore. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>i need some pointers as to how to write one... You have hardware done but didn't say what it consists of? An equally general answer would be "line by line" but now I'm just being silly. ;^) The 877 has 2 PWM channels, perfect for speed control of DC motors and servos or other PWM input sensing. Also a good number of A/D inputs and I/O pins. Way too flexible to guess your desires. Go to http://www.htsoft.com and get the PICC Complier Demo ASAP. You'll learn a ton in the 21 days it's good for. Look and learn from it's ASM output. Here's mine w/an F877 and PICC as I *hope* to navigate the first half of the Journey Robot maze at the SME competition this weekend... http://www.reedonline.com/brian/robot/bedlam/ - Bri >hello, >does anybody has any programming experience with this PIC16f877 for simple >robotics use??? using "C" or assembly will be alright.. >i need some pointers as to how to write one... >i have all the hardware done but now it is the software that is bugging >me.... > >thanks >Henry -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

How do you control your motors? I am building a similar system. I also use PWM to control the speed of my motor, but it makes lot of noise. What is your PWM frequency? Any sensors for your robot? I have total of 8 IR sensor (one of each side and one at each corner), but I don't know how to write the code so that every possible combination of detection is covered. Any tips? Thanks Thomas {Quote hidden}>From: Brian Reed <.....piclistKILLspam@spam@REEDONLINE.COM> >Reply-To: pic microcontroller discussion list <PICLISTKILLspamMITVMA.MIT.EDU> >To: .....PICLISTKILLspam.....MITVMA.MIT.EDU >Subject: Re: [PIC]: PIC16f877 >Date: Thu, 5 Apr 2001 02:26:42 -0400 > > >i need some pointers as to how to write one... > >You have hardware done but didn't say what it consists of? >An equally general answer would be "line by line" but now >I'm just being silly. ;^) > >The 877 has 2 PWM channels, perfect for speed control of >DC motors and servos or other PWM input sensing. Also a >good number of A/D inputs and I/O pins. Way too flexible to >guess your desires. > >Go to http://www.htsoft.com and get the PICC Complier Demo >ASAP. You'll learn a ton in the 21 days it's good for. >Look and learn from it's ASM output. > >Here's mine w/an F877 and PICC as I *hope* to navigate >the first half of the Journey Robot maze at the SME >competition this weekend... > http://www.reedonline.com/brian/robot/bedlam/ > >- Bri > > > >hello, > >does anybody has any programming experience with this PIC16f877 for >simple > >robotics use??? using "C" or assembly will be alright.. > >i need some pointers as to how to write one... > >i have all the hardware done but now it is the software that is bugging > >me.... > > > >thanks > >Henry > >-- >http://www.piclist.com#nomail Going offline? Don't AutoReply us! >email EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body > > _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

i am using stepper motor, so i just need to input a clk pulse, a direction input, an enable input.... i have 10 IR sensors....but should be using 2 for table edge detection purposes, leaving 8 for object detection of the front, side and rear....also have a couple of contact sensors around the robot... all done....now...i am at a lost of how to start programming the robot....have a PIC16f877 and a programmer board too....and also a "C" compiler that comes with it... I know somehow what to do but not exactly know how to do it....i know i need to output the 3 control pins states for my stepper motor according to my sensor input, should be based either on a polling method or an interrupt method.....for table edge detection and contact, I should be using interrupt, which is faster in response and since the task is of higher priority.....polling can be done probably for the sensing of obects near the robot.... anyone can help recommend a good "C" compiler or assembler and has a simple example code for me to learn as I program??? Henry {Original Message removed}

I built a similar robot too (except with only 8 IR sensor and some light detector). I think we are both stuck at how to analyze the input data from the detectors.... :( Thomas {Quote hidden}>From: Henry Low <@spam@eng70245KILLspamNUS.EDU.SG> >Reply-To: pic microcontroller discussion list <KILLspamPICLISTKILLspamMITVMA.MIT.EDU> >To: RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU >Subject: Re: [PIC]: PIC16f877 >Date: Fri, 6 Apr 2001 03:34:39 +0800 > >i am using stepper motor, so i just need to input a clk pulse, a direction >input, an enable input.... >i have 10 IR sensors....but should be using 2 for table edge detection >purposes, leaving 8 for object detection of the front, side and >rear....also >have a couple of contact sensors around the robot... >all done....now...i am at a lost of how to start programming the >robot....have a PIC16f877 and a programmer board too....and also a "C" >compiler that comes with it... >I know somehow what to do but not exactly know how to do it....i know i >need >to output the 3 control pins states for my stepper motor according to my >sensor input, should be based either on a polling method or an interrupt >method.....for table edge detection and contact, I should be using >interrupt, which is faster in response and since the task is of higher >priority.....polling can be done probably for the sensing of obects near >the >robot.... >anyone can help recommend a good "C" compiler or assembler and has a simple >example code for me to learn as I program??? > >Henry >{Original Message removed}

i am able to give the microcontroller the required TTL 5v for triggering if there is an object nearby and stuff....i also fully understand and know how i want my robot to behave but i really do not know how to put it to computer language and let the MCU know what to do ..... let's hope for some great mentor..... i believe our robot is merely a very simple one with no complicated algorithm...we just need a sample code to play with.....and we will be on our own soon i guess.... Cheers {Original Message removed}

>How do you control your motors? I am building a similar system. The PWM outputs through optoisolators. >I also use PWM to control the speed of my motor, but it makes lot >of noise. What is your PWM frequency? I had a lot of high-frequency noise in my first attempt so I turned down the PWM frequency. I wish I knew what it is! I am using 1:4 duty cycle(?) (CCP1CON & CCP2CON = 0x0C), PR2=0xFF, and T2CON=0x06. My frequency meter says it's about 236 Hz, but I don't get the same answer by working the equations. >Any sensors for your robot? I have total of 8 IR sensor (one of each side >and one at each corner), but I don't know how to write the code so that >every possible combination of detection is covered. Any tips? Just 2 forward IRPDs looking down to detect maze lines (for now). Perhaps a state engine will work better with more inputs, I have an article I want to read about SE's ... you might find it on their website... Embedded Systems Programming magazine, December 2000. Let me know what you learn! - Bri -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spamBeGonelistservspamBeGonemitvma.mit.edu with SET PICList DIGEST in the body

> all done....now...i am at a lost of how to start programming the > robot....have a PIC16f877 and a programmer board too....and also a "C" > compiler that comes with it... > I know somehow what to do but not exactly know how to do it....i > know i need > to output the 3 control pins states for my stepper motor according to my > sensor input, should be based either on a polling method or an interrupt > method.....for table edge detection and contact, I should be using > interrupt, which is faster in response and since the task is of higher > priority.....polling can be done probably for the sensing of > obects near the > robot.... > anyone can help recommend a good "C" compiler or assembler and > has a simple > example code for me to learn as I program??? I am finishing the code to control a stepper motor. Key features : - Speed control - Forward/backward - Program capability (e.g. 10 turns + 5 steps) - Ramp capability for starting/stopping the motor - Valid for any type of stepper motor - Serial interface with a host This is a project that had to be finished a week ago but that has been postponed due to my job commitments. As soon as I finish and test it (hopefully in a week) I would like that people interested in this subject use and test the program. If anybody is interested, please drop me a note and I will send code, flowchart and diagrams. Cheers Joan -- http://www.piclist.com hint: To leave the PICList TakeThisOuTpiclist-unsubscribe-requestEraseMEspam_OUTmitvma.mit.edu