Let's Make Robots!



it's the ultimate solar rover

based on Picaxe 18X

it soaks only 25 uA in idle mode

it have a brain

it's i/o modular through 2.5mm strips

it's efficient

it's small (L:66m W:37mm)

 the nemesis of beam robots


the actual schematic


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i need some advice about the drive train

now i have put those two motors and the big belly capacitor


thank you for the advice

about the cap now it's a bulk 6800 uF

and it provide enaught energy to drive both motors for 50 mS @ 3v

it's enought ini order to move 

bigger cap means longer motion period but longer idle time

anyway cap size have to be reduced


i was thinking about thread bealt

but i fear too mugh friction




what oddbot said, usually in solar robotics/and or beam supercaps are used instead or regular caps because they store a lot more low volage eneregy than normal caps, unless your using like 100 panels lol

yep that cap would be great for this bot , 5,5v is ok


i have done some tests and it seems motor have enought torque to drive  thread bealts....

now i am trying to handcraft a decent drivetrain


We had a major snowstorm on Monday and I got a chance to take a serious look at your circuit. I dug some parts out of my junkbox and tried a few things:

1. The motor driver chip is not needed if you use a PICAXE 20M. There are 9 output pins and 3 ADC's. 8 output pins can be used to drive the 2 motors and the 9th used to power the CdS sensors and voltage reference., The design is easily transfered. 

2. The little gear / pager motor is really quite efficient and requires about 25 ma.  This means that it can be driven by a single output pin on the PICAXE. Yes it does work. This means only 4 pins are required to drive the motors.

3. You will need to prioritze the rsponse to the CdS and microswitch sensors. The ADC readings of the CdS will never be the same and with only a 50 millisec pulse to the moters before sleep, you will never get past the CdS response to check the micro switches and you with have a standard SMARTBEAM Photovore.

4. Because of the internal resitance of the memroy backup caacitors, you may not get a large enough current pulse to drive the motors. I haven't tried this yet woith the little geared pager motoers, but it has happened with regular motors. ****I have now tried the 0.047 memory backup caps and they do work! The trade off is a very long poriginal charging of the cap.




1.  2.   I have no experience with picaxe output current capability, those gearmotors are rated to soak 180mA stalled. I do not know how can respond picaxe output at his level of current demand. Anyway in this aplication the size is not so critical. I will try to use your advice for the next robot: the 1 inch cubic bot

 3. please be patient, my english is crap and i can not understand what you mean

4. agree, many backup caps do not provide enought current to drive motors. Now I am trying to fit a 6,3v electolitic cap . In the pic the cap is a 16v



Each PICAXE pin can easily output 25 milliamps. Because the Sonimoro is so light weight, there is very little loading on the motor and the the power requirement is vey low..  I dug out an old BEAM test platform with the geared pager motors and measured the currrent at 25 milliamps.

Measure yours and try it!

The stall rating of 180 milliamps only occurs when the wheel is locked.




This bot is awesome awesome awesome! You MUST post a schematic of the circuit for us.

[EDIT] Just saw that you did.

i have uploaded last schematic


that's it

the Somimoro with bigfoot drivetrain

it's 40% less eficiet opposed to original lo-frictionsetup

anyway it' acceptable and with this setup it can seriously rover the envirenment...or not?



develop more I/O modules (feelers, lights, buzzers, ir,......)

glue a piece of pvc to fix drivetrain mechanical stability