Let's Make Robots!

engineering phase of my first robot, lot of questions !

Hello everybody,

First of all is a brief description of the robot I dream to built :

- processor ARDUINO

- Outside off-road (on the grass of my back yard), night and day

- completely autonomous guardian robot ( to chase the squirles off my vegetables garden)

- auto-recharging by bay charging station and also solar panel (I live in California, a lot of sun)

- loaded with some weapon like sound, light or projectiles.

- eventually the option to install a camera and R/C command (for the fun)


The questions :

- where to find a goods cheap wheels big enough to drive the green (grass 4 inches tall) ?

- is it better to choose the battery first and challenging the robot the "enter" in the Ah, or do the complete robot and after mesuring the amps necesary ?


thx for your answers, see you in a bit for more question.


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here is the sequence I have in my mind about how the robot acting in the backyard :

- with no intrusion : patrolling every where in the backyard.

- with an intrusion : moving quickly close to the stranger, disuade the stranger to leave, if not aiming and shooting.


This is the bases comportments of my robot, I need to enter in details to find the appropriate sensors and solutions.

Bellow is the processing diagram of the charging function for my robot, using a solar panel, and dock charging station.


It's only the process, not a shematic of the system, you are not going to see how that going to work, not yet. But I have my ideas about how to do.

Hi Eric,

considering the height of the grass, i would suggest tracks. If you use wheels, you will need something like 10 cm radius which is very big for small motors. Tracks have small transmission wheels, so you will have less speed and more punch and less getting stuck in the grass.

I suggest you find a cheap toy at first and install your electronics. It will save you a lot of time and money to go to your first finished prototype. We all prefer to do everything ourselves, but it is more important to have something working. It is good for the mind and it helps concentrating on important questions.

Make it run with a power supply and measure consumption with an amp-meter while you have the different modules working. This will help you select the battery depending on the autonomous run time you want. This will help you detect the hungry modules and adapt your software (or even hardware) accordingly.

I have never made a charging station, though I think it is a primary need for a robot. IR may be difficult to use outside after a few meters. You may use sound to home on your charging station, then IR for precision docking. Ultrasound are said to be very directive, may be they could be used? You may use a high power IR led plate for basic homing and a lower power IR for docking.





a lot of goods in your comments, that help a lot.

thanks for all.

For a garden robot I would also go with tracks only. In a garden you have obstacles like rocks, leaf, rotten tomatos, high grass which is not the best environment for a wheel based robot or you need offroad wheels and then six of them to make sure your robot does not get stuck and the squirrel is laughting his ass off ;-)

for navigation I would probable use a compass module for the general navigation and the closer to the charging base IR with a high power directed, modulated and narrow beam. A Solar panel will charge the robot any time when sun is shining and during the night it could charge via base station if needed. Also the base station could be powered by a solar panel to charge a lead acid battery.

It might be already in your flow chart but I can't read it...too small. 

the flow chart picture is larger now.



I will thinking about tracks.

Thank for all directions you give to me, I will study all.

also, my robot has a name now :


Autonomous Robot Chaser Of Squirrels

LOL, cool name ;-)

Please keep posting news and pictures and ... yes ... videos as soon as you have something to show.

dont worry, I will post

I know, this project look like on stand by, but not at all, I am still thinking, calculating, budgetting (is it english ?)


I found that year ago, and may be that can be a very good option for driving on my none flat backyard.



Somebody has an idea about the making of the "wheels", I thought to use a molder and cast the urethane (http://www.hobbysilicone.com/silicone.htm)