Post by thread:[OT]: Motor Driver. Need Help!

I think I will be using the L298 to control my motor. What do you guys think? Thomas {Quote hidden}>From: Roman Black <spam_OUTfastvidTakeThisOuTEZY.NET.AU> >Reply-To: pic microcontroller discussion list <.....PICLISTKILLspam@spam@MITVMA.MIT.EDU> >To: PICLISTKILLspamMITVMA.MIT.EDU >Subject: Re: [OT]: Motor Driver. Need Help! >Date: Fri, 23 Mar 2001 19:05:10 +1100 > >Thomas N wrote: > > > > Hi everyone, > > > > I am building a small robot and I run into the problem of finding the >right > > Motor Driver and the method of controlling the motor. > > > > I want to be able to make the robot go forward, backward, and stop. I >also > > want to be able to control the speed. Controlling the speed, I think I >can > > use the PWM method to control it. > > > > Questions: > > > > 1. If I use PWM, at what frequency should I use? > > > > 2. Is there any motor driver out there that can control 2 motors? (I >need 2 > > motor drivers) > > > > 3. Do you have the schematic of the motor driver circuit? I will need >it to > > build my driver. > > > > 4. Any other method to control the motor and its speed? > > >A good beginner system is to use a single NPN transistor >to drive the motor, either on/off or with pwm. That depends >on software. > >For motor reversal you can use any DPDT relay (2x changover) >to simply reverse the motor leads. As your robot spends most >of it's time going forward this can be the most energy efficient >system for a battery operated robot. > >Search Yahoo for "hobby robot motor" and see what comes up! >:o) >-Roman > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> > I am building a small robot and I run into the problem of finding the > > right Motor Driver and the method of controlling the motor. > > I want to be able to make the robot go forward, backward, and stop. I > > also want to be able to control the speed. The choice for hobbyists for me is pristine clear : use a stepper motor. You have with it a perfect control of position and speed as far as you do not surpass the motor capabilities. I have finished a small project for controlling a stepper motor with a 16F84. It works, it is easy to understand and you can modify it since it is somewhat documented. This weekend I plan to add a serial communication capability to the controlling PIC and later I plan to connect two such devices to a third PIC so as to be able to making coordinated movements (yes, as you can guess, I am building robot rover). If you (or somebody else) is interested in the subject I can e-mail the assembly code, the program flowchart and the electric drawing (as soon as I have it finished). Cheers Joan -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Joan, I know that using the stepper motor is easier to control the its motion, but I happen to have the DC motor and that's what I have to work with. I have some stepper motor but they run on 12V. They are quite heavy and it is to large for my tiny robot. I will use them on my next project. Regarding your project: Why don't you just use ONE 16F877 to do all that instead of ONE 16F84 do motor control and ANOTHER one to do the interfacing? If possible, please send me your code at .....thomasn101KILLspam.....hotmail.com Cheerios! Thomas {Quote hidden}>From: Joan Ilari <EraseMEjoan.ilarispam_OUTTakeThisOuTTERRA.ES> >Reply-To: pic microcontroller discussion list <PICLISTspam_OUTMITVMA.MIT.EDU> >To: @spam@PICLISTKILLspamMITVMA.MIT.EDU >Subject: Re: [OT]: Motor Driver. Need Help! >Date: Fri, 23 Mar 2001 20:04:44 +0100 > > > > I am building a small robot and I run into the problem of finding the > > > right Motor Driver and the method of controlling the motor. > > > I want to be able to make the robot go forward, backward, and stop. I > > > also want to be able to control the speed. > >The choice for hobbyists for me is pristine clear : use a stepper motor. >You >have with it a perfect control of position and speed as far as you do not >surpass the motor capabilities. I have finished a small project for >controlling >a stepper motor with a 16F84. It works, it is easy to understand and you >can modify it since it is somewhat documented. This weekend I plan to add >a serial communication capability to the controlling PIC and later I plan >to >connect two such devices to a third PIC so as to be able to making >coordinated >movements (yes, as you can guess, I am building robot rover). If you (or >somebody >else) is interested in the subject I can e-mail the assembly code, the >program >flowchart and the electric drawing (as soon as I have it finished). > >Cheers > >Joan > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> Joan, > > I know that using the stepper motor is easier to control the its > motion, but > I happen to have the DC motor and that's what I have to work > with. I have > some stepper motor but they run on 12V. They are quite heavy > and it is to > large for my tiny robot. I will use them on my next project. > I recently purchased 4 stepper motors from Jameco. Price : 5.95$ (1.8 deg) and 4.95$ (7.5 deg) per unit. I don't think that cost could be relevant in this case. But if what you want to do is to control a DC motor ... You should think that it is very probable that you need a gearbox (to reduce the speed of motors to an appropriate value for moving a given joint) and then the total cost you can bet that will be high :-( > Regarding your project: Why don't you just use ONE 16F877 to do all that > instead of ONE 16F84 do motor control and ANOTHER one to do the > interfacing? Good suggestion/question. The fact is that I do not have any 16F877 and I have 4 16F84s. Moreover I do not like 40 pins ICs (small is beautiful) but I will probably port my programs to a 16F876 (28 pins is not too much), control the two motors from this PIC and use its UART to communicate with a host. With this CPU I will have many I/O free pins for other purposes. The 16F84 approach has also the advantage of being based on a "distributed" approach, unloading the main CPU of awkward tasks as motor control, an idea which I like a lot ! Best regards Joan -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads