Sumovore Manual
Step 20 & 21 - IR Edge Sensor PCB Connectors and LM555:
We’re now working on a brand new board - the Edge Sensor PCB. This board holds the front edge sensors, and the infrared
transmitting circuitry.
Let’s start by installing the LM555 chip in the spot labled ‘IC4’.
MAKE NOTE of the direction you install the chip! You want the end with
the round dot in the corner of the chip to be near the notch in the symbol
printed on the PCB. This is the only chip we’re not putting in a chip carrier
because it would make the circuit board too tall to properly fit on your
Sumovore, so it’s very important that you get it right the first time. Check
the next assembly picture on this page to make sure it matches what you’ve
done BEFORE you solder it in.
After the 555 installation, pivot the 90° connectors into positions ‘Plug 1’
and ‘Plug 2’. These will provide mechanical and electrical connections to the
rest of the Sumovore’s circuitry.
The Solarbotics Sumovore
Building the Edge / IR Transmitter Electronics - 5
Steps 20 & 21: LM555 and 90° edge connectors
Step 21:
90° Edge connectors
(x 2), plastic side up
Step 20:
Install the LM555
(corner dot up!)
Step 22, 23, & 24 - 100k, 30k and 240 Ohm Resistors:
If it weren’t for resistors, we’d have a whole heckofalot less
soldering to do! Unfortunately, that’s not the case, so let’s get to
work. You don’t have to watch the way you install resistors, but
it’s always nice to have all the resistors lined up with all the gold
bands on one side. It’s the sign of a true Sumovore craftsman...
Start with the 100k (Brown / Black / Yellow) resistor and solder it
into position ‘R5’. This resistor limits how much signal is sent to
the transistor that powers the IR emitter LEDs (yet to be installed).
Follow up with the 3k (Orange / Black / Red) resistor and install it
in position ‘R6’. This resistor helps set the frequency that the
LM555 chip will flash our IR emitter LEDs.
Round up the five 240 Ohm (Red / Yellow / Brown) resistors and
install them in positions ‘R7’, ‘R8’, ‘R9’, ‘R10’, and ‘R11’. These
resistors limit the current going to the edge-detector module
emitters (yet to be installed).
Step 22:
100k
(Brn / Blk/ Yel)
Resistor
Step 23:
3k (Org / Blk/ Red)
Resistor
Step 24:
240 ohm
(Red / Yel / Brn)
Resistor (x 5)
Steps 22, 23, & 24: Resistors