"EL Skorpiano" Autonomous Left/Right Brain/Eye Picaxe 08M2 - Eco Series


New Member
"EL Skorpiano"
20DollarPicaxe 010~1.jpg (Q:-...how can i enlarge my pictures in the post ?)

This is a project based on Picaxe 08M2 chips.
It is an Autonomous Robot using Stepper motors and Infra Red Leds as sensors
Below is its third support leg..... a Glowstick enables a smooth transit over bumps and curves..(and excuse to break a glow stick)
20DollarPicaxe 005~1.jpg
It has both Left and right Brain halves - both programmed with complementary but opposite coding.
Its Right InfraRed Eye is connected to its Right Brain (Artistic side) and controls the Left stepper motor.
Its Left IR Eye is connected to its Left Brain (Logical side) and controls the Right side stepper motor.

Right Brain Code :-
;"EL Skorpiano"
; Right Brain Sub 20 Dollar Robot
; Picaxe 08M2
; www.picaxe.com <Gareth>    - aka youtube "Chiprobot"

disconnect          ; free_s up the programming pin so you get extra pins for sensors 
                    ; (hard reset required to program chip again though)
dirs = %00010111    ; Set pin directions - 4 for stepper - 2 for input devices
for b0 = 0 to 999  ; Give robot a limited life ...."thousand clicks"
 for b1 = 0 to 3    ; Stepper sequence count
  if pinC.5 =1 then ; Check to see if the Infra Red detector has found something
   lookup b1,(%00000011,%00000110,%00010100,%00010001),b2 ; preload Reverse Stepper (high torque version) sequence
   lookup b1,(%00010001,%00010100,%00000110,%00000011),b2 ; preload Normal Stepper (high torque version) sequence
 pins = b2          ; send to stepper motor
 next b1            ; increment stepper sequence position
next b0             ; Next life "Tick"
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New Member
Right and Left Brain Halves

Here are the Left and Right Brain halves......
One 08M2 has been made to directly fit the stepper-motor driver like a back pack (meaning the stepper has its own exclusive mcu driving the step sequences, now there is an interesting concept)
20DollarPicaxe 043~1.jpg
The second 08M2 was added to a custom pcb board i designed as experiment (later i will design a solder mask version)
20DollarPicaxe 045~1.jpg
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New Member
Programming cable &quot;Eco Style&quot;

Because the stepper motor driver has 3 extra inverters left over ....
.... its possible to use these to invert the RX/TX signal from cost effective USB_FTDI converters (ie $2 ones)
Here you see my "Hot Shoe" picaxe with modified stepper board converting the signal to allow programming eco style.
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New Member
Simple Infra Red Eyes

The Eyes are made from a Infra Red Led and Infra Red dectector diode.
It is used to detect reflected IR off an object (or it could be inverted to detect cliffs instead)
20DollarPicaxe 052~1.jpg
The detector is shielded to stop it detecting stray IR leaking out from the side of the IR TX LED..
You have to be careful what shielding material you use as IR can TX through materials like heat shrink and "duck" tape.....I am using about three turns of self amalgumating tape... not forgetting to tape the bottom of the RX LED because that also has an effect.
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Senior Member
Another great Bot, Gareth! You are amazingly prolific, and your love of stepper motors is second to none. Happy New Year to you, your son and El Skorpiano.


Senior Member
Great project! One remark, the FTDI converters can actually invert the signals themselves (inverting/non-inverting is set in MProg where you download the parameters), so a hardware inverter is not really necessary.


New Member
I am using an FTDI converter of the common CP2102 type .... i am not sure if MProg can program these.
The CP2102 is pretty bomb proof .......however not all manufacturers allow you to program the firmware (i have tried numerous programs (inc SiliconLabs programmer).... to date>>> nada ).
I use the programming plug for my other mcu (ie non Picaxe) devises as well (these generally dont need inverting) .... so the simple hardware inverter for picaxe is an easier solution.


New Member
Ah haaa.......That would explain a few things this end...... Thanks for the info - every day is a new day to learn.....(means i can officially give up my search for 2102 firmware programmer, oder!)
Seams there are three separate beasts (and more i guess) not to be painted with the same brush ........ Microchip MCP2200 chip, FTDI FT232RL chip, and Silicon Labs CP2102 chip.