Sumovore Manual

The Solarbotics Sumovore
Troubleshooting (cont’d)
Sumovore not seeing the white edge line? Start with the front edge sensors board (good thing that sensor board is easily
removable, eh?). The sensors are pretty good at detecting white, so leaving the trimpots in the middle position as a default is a
good place to start. You’ll only need to really mess with them when you’re setting up for line-follower mode.
! One or more IR reflector sensors may be in backwards. Make sure they’re ALL in the correct way around.
! The IR reflector sensors have a very short range, so if they’re further than 1/4” (7mm) from the surface, they may not see
the line. Pull the sensor board downward a bit on the pins and see if that makes a difference.
! Try tuning them to maximum sensitivity by turning the single-turn 10k trimpots on the corner fully clockwise.
! The IR reflector sensors are sensitive to infrared light, which means what you might think is reflective may not be to the
sensors. Regular paper reflects IR well, as do your fingertips. Many white plastics look “transparent” to IR.
! The Sumovore needs the front IR circuit board to be installed to show any sign of life. If it isn’t in properly or is installed
backwards, nothing will happen!
Sumovore not seeing Opponents? It’s time to watch those red LEDs!
! The rear red LED indicates that the IR transmitters are working. If there’s no light, one (or both) of the clear IR LEDs may be
in backwards, or the rear red LED is in backwards.
! If your rear red LED is on, but still no detecting is happening, make sure you’ve followed the IR transmit frequency tuning
we discussed in “Building the Body - Step 17”. Twiddle that 20k multiturn trimpot on the edge-detection board!
! Check the IR detectors are working by using any TV / VCR / DVD remote control. Point it at each IR detector on the top
corners of the mainboard while pressing any button. Does the red LED right behind the detector blink? If yes, the problem
lies with the IR transmitter. If no, then make sure you have the indicator LEDs installed the correct way and the solder
connections are secure. If you have a multimeter, see if you can measure 5 volts between the middle and right pin of the IR
receiver.
! If you’re fortunate enough to have an oscilloscope or frequency-counting multimeter, try measuring the frequency at the
points labeled “DIAG2 - 555 Output” on the edge-sensor board. You should see a nice square wave pattern, or a
frequency count in the 30 to 60kHz range. Tune it to be between 34kHz and 42kHz for best performance.
There are Bite Marks on my Sumovore! Stop throwing it for your dog to catch. And keep your cat off your workbench.
I don’t have enough traction! Try layering both traction bands onto your wheels for a softer tire. And clean them between
matches with rubbing alcohol. And don’t forget, you can “bulk up” your Sumovore to 500 grams for maximum traction!
My Startup timer is too Long/Short! Ah, that’s easy to fix. If your Sumovore has the trimpot on the top right side of your
discrete brainboard, then turn it clockwise for longer delay; counter-clockwise for shorter.
My Sumovore is turning too Much/Not Enough when it sees the white line! Another easy fix. The two trimpots at the middle
of the discrete brainboard each adjust the time the Sumovore spends backing up and turning when that side gets activated. If it’s
barely backing off and turning when the right edge sensor touches the line, then turn the middle-right trimpot more clockwise.
Line-follower mode sucks! Line-follower competitions require finesse and skillful tuning. Line follower mode uses the black line
to turn off the motor on the side that detects the black line, which rotates the Sumovore back until the edge sensor no longer sees
the black line. Here’s the proper tuning procedure:
1) Turn both 10k single-turn trimpots full counter-clockwise.
2) Place your Sumovore on a white section of your line-follower track.
3) Slowly turn each pot clockwise until the motor on that same side activates.
4) Repeat for the other side
If you’re going to be doing lots of line follower, you may want to take advantage of the holes on the front sensor plate near the
edge, and mount a low-friction slider to make your Sumovore quicker and more maneuverable.
My Sumovore has edges sensors that are touchy and hard to tune! This is more common if you have a brighter-coloured
front plate, like yellow or white. The IR light from the edge sensors is being reflected around by the backside of the plate causing
false readings, so colour the backside of the front plate black to reduce these unwanted reflections.