Resets

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1. Are you sure it is resetting? I like to make sure by placing a small bit of code in my program before the loop and after the main. Check out this tiny chunk here: That code causes the lights to flash up the row as soon as the bot is turned on. if you see this pattern over and over, your bot is resetting.

2. Wiring issues: If your robot has wire sticking up everywhere, it could easily be picking up stray RF (radio frequencies) or just plain be wired wrong. Check out the bot below. Every wire lays flat and travels as strait as possible.

3. Batteries: Arrrgh! This is the most annoying! Your robot has two sets of batteries in it. The AA bateries power the motors and the 9 Volt powers the logic. Believe it or not, if either one drops below a certain level, your bot may slip into an annoying reset cycle. Oddly, it could be transient. For example, I have seen bots that only reset if it is running on the floor. Pick it up and hold it, and it works fine. What happens is resistance in the motors cause the current draw to go up. If the motor is under load, the power consumption goes up. Pick up the robot and the wheels no longer touch thus resistance goes down. Suddenly, it works! Anyway, in my test, anything below about 8.8 volts will likely give you trouble. A slightly used battery A new copper top battery

4. Assembly issues: Like I said above, any resistance will cause increased current draw from the motors. Usually this friction comes from issues in the gearbox. depending on what gearbox you have, a lot of friction can come from the shrink tubing rubbing against the casing.If this is the case, cut it back from the casing.

5. Friction: If your motor makes that horrid squeaking noise, chances are you need to grease it up. I took this one off and lubed all the points that rotate. Be liberal about it, get it everywhere that parts rub or touch.

6. So Annoying!: I have seen this one twice. The back of the gearbox pushes hard against the battery pack causing the capacitors to rub against the motor shafts. How frustrating is that?!?!

7. Simple Code: Sometimes it's good to live life on the edge. In this case tossing out any "extra" code may make it work better. Check out this section of code that regulates motion. I blew away all the delays...make it simple.

8. Resonator Noise: This excellent suggestion comes from Bryan Moffitt. Move the wire connecting the resonator to ground over to the same row of pins grounding the PIC.

9. Twist dem' wires: Another easy improvement is to simply twist the wires heading to the motor. This will reduce feild effects and thus may cut down on noise. Easy fix! do it anyway.

9. Filter caps: Forgive me here. I am not going to practice what I preach. As a general rule, try not to place parts OVER other parts. I admitt it, by this time I am getting pretty beat. Anyway, filtering is always good practice. Here I have placed a .47 pF cap across the PIC spanning from the input power to the ground. A whole range of caps would be OK for this. Try to get something between 0.01pF and 0.5pF. The samller the better. Bryan again would likely and rightfully say it would be best placed low and close to the PIC. BTW I got my caps a Radio Shack. 2 for 99 cents.

10. Move da' whole darn power supply: Welp, this is getting close to the last resort. I must admitt that it is good practice. Motors can be really nasty sources of all kinds of noise and here I've told you to put the driver right smack in the middle of the board! Perhaps another location would be preferred....Bryan recommends that perhaps the power supply could be simply moved closer to the PIC. Once again I admit my intelectual defeat. It simply would be best further away from the motors and closer to the PIC.

11. Just plain careful wiring: By gosh by golly..Try hard to not have any wires crossing supplies to the Resonator or PIC. Both of these are really sensitive. (obvious if your still having trouble)

12. Move all 5 volt and ground wiring to one side of the Breadboard:

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PIC is a registered trademark of Microchip Technology Inc. in the U.S. and other countries.
MikroBasic is a registered trademark of mikroElectronika Inc. in the U.S. and other countries.

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