Multifunction arduino robot - beginer

[Radu_Andrei]

Hi everyone.
I've been thinking for the last half hour how to formulate this topic, and I could not come up with a decent way, as fundamentally I miss information about the name of most components, the wiring, and the programming, which I think means 99% of the project. With the hope that you are not offended and irritated by my humble 1% of knowledge (which might also be overestimated), I present my ambitious project.

One 20-25cm tall robot, with 3 main sets of functions. 1. Movement (basic 2/4 wheels system), 2. Tilt and pan head function, 3. Stepper motor control for varius applications. 4. Remote control. Please find attached my photo with my marveling pile of knowledge. Not.


I did not add more components, as I don't now if I can run 4 tt geared motors, 2 servos, and 1 or 2 steppers of 1 arduino, or I need some expansion thing, or multiple arduinos.

Function number 3 is simple for someone who knows this stuff. Besides the other controls, there will be an extra joystick module for a steppers which when pressed(sideways) will act as a push button and move the stepper in 90 degrees divisions in the coresponding rotational point. 0, 90,180,270. The application of this is multiple, so I would not bother you with details. Like turning a cube on each of its 4 faces, when sited on a table and viewed sideways.

Functions 2 and 1 are for sure something you come accross all the time.

All this remote controled, by either a made from scratch remote, or a wireless ps2/3 controller, or whatever else.
The desired budget is 200 euro (221 dollars,171 pounds), but I think you are much more qualified to define the costs of such a project.

I don't even know where to start the conversation, not to mention the project.

Thank you for reading, and hope to hear from you.
Andrei

[john swift]

Hi Andrei

just to get the ball rolling before some one how uses the arduino replies

looking at the photo it looks like it shows the Arduino nano

which has 14 Digital I/O Pins (of which 6 provide PWM output)
and 8 Analog Input Pins

many arduino kits either use 4 pins per stepper motor
via either 4 of the 7 darlinton transistors in a ULN2003 ic
( instead of all 8 in a ULN2803 I would use )

or a L298N dual "H" bridge IC that has 4 input pins and 2 enable pins

These solutions are OK if your learning to use the arduino

but a ready made stepper motor driver with just 2 inputs - step and direction
makes more sence to me as it save arduini pins - uses 2 instead of 4
and gives you control of the current through the motor coils

for low power motors have a look at the A4988 & DRV8825 used on 3d printers


how many motors do you need to control at once

radio transmitter & receiver modules are readily available
https://www.instructables.com/id/RF-...dule-and-Ardu/

John

[Radu_Andrei]

Hi John,
I guess the remote will have 4 joystick modules. First for the 4 geared dc motors used for movement. Second for the two servos used for pan and tilt option, and third and forth for 2 steppers (described in the previous post as Function nr 3). And on and off button, and maybe some light buttons, but this are optional.

I am a bit limited by the size of the robot, which should have a base not larger than 10-12cm (4-5 inches), and no more than 25 cm in height, that is why I used a arduino nano, but anything else might work. The thing will have a wooden/plastic case on top to cover all components, and I cannot continue with the design until I figure out what and how large will be this arduino thing.

I intend to learn arduino, but I can't figure out where to start yet, and I would preffer to narrow somewhat the learning to my specific need. It seems to me right now, that in its entirety, this is a topic which requires years to master.

Thanks for the reply.

[AndyUK]

My question is what do you want this robot to be? Something smart that can control itself, with a remote to change it's behavior, or do you want it to be always remote controlled (like a remote control car)?

In theory, if its option 2, you don't need an arduino for the movement, pan/tilt, or the remote control. The arduino is only really needed for the stepper motor control you mention. You could easily take an input from a remote control receiver to instruct the arduino and therefore the steppers. Look at remote control plane tutorials for basic analogue servo control - the pan tilt module is two of these - very simple. This is a good tutorial from sparkfun - but look at the 'Traditional RC Application' photo - that is how simple the setup is (although it is missing a battery!). I'd then use essentially the same setup to a brushless speed controller and brushless motor for the movement.

Regards Arduino programming, the skills are the same whichever size you get. Start with a nano and try to get an LED blinking (there are lots of tutorials online). Get a cheap clone of the arduino though to save your budget for the main event - they work exactly the same. £3 on eBay should do you.

[hanermo2]

Forget 200£.

200£ per axis is closer to the truth, if you want anything with decent accuracy, repeatability, and resolution.
And that is in materials costs, alone.

Anyone can make decent high-precision mechanicals, per axis, with any decent lathe.
But it is cheaper and easier to buy them, and they cost more than 100£/axis, and a lot more for really good ones.

Define your expected usage, payload, repeatability, speed, and resolution.

[AndyUK]

Forget 200£.

200£ per axis is closer to the truth, if you want anything with decent accuracy, repeatability, and resolution.
And that is in materials costs, alone.

Anyone can make decent high-precision mechanicals, per axis, with any decent lathe.
But it is cheaper and easier to buy them, and they cost more than 100£/axis, and a lot more for really good ones.

Define your expected usage, payload, repeatability, speed, and resolution.

???

OP has never mentioned anything about needing high levels of accuracy strength or resolution. The requirements he has stated (simply a small remote control device able to translate, and have a pan/tilt, and drive a stepper motor or two...) are easily achievable in this budget. Think RC car budgets, not CNC.

[john swift]

web search result for arduino joy stick shows it to have
2 potentiometers to give you analoge control of the X & Y position
and a n/o switch operated when you push the joy stick down

https://www.best-microcontroller-pro...-joystick.html

[Radu_Andrei]

Hi AndyUK.
Just a "always remote controlled" robot. Meanwhile I found on youtube a detailed tutorial on how to make a simple robot chassis. I'll watch the tutorials you've mentioned to figure out the pan tilt and check the RC thing.
What I could not find is function nr 3, or moving the steppers in the way I want. I've also seen keyboard modules with 4 buttons which can work as great as a joystick module. It is the same for me. Pressing button nr1 gets the steper at 0 degrees, nr 2 at 90, 3 at 180, and nr 4 at 270.

I can use this function in many things (ex: furniture secret compartiments operated by a mixture of electrical and mechanical parts), but for this specific case, it is as you can see in the foto in the left side. . I need to rotate parts of his heads, and might also be useful for body configurations, on 4 sides. It might be as simple as some writing on this 4 sides, but for now, I don't know exactly all the details. I just need the function done. (wiring and programming). The body and the case, I'll figure out after I find out the exact size of the electronics needed. (which does not have to be arduino, it can be anything else. If it works as intended, then I'm fine with whatever).

hanermo2.
As AndyUK said, I do not need a cnc. I already built one last year, and I spent way more than 200 whatever currency on axis. This time, I need remote control car with the appearance of a robot. A toy in fact.

[Radu_Andrei]

john swift.
So it has 4 directions or only 2 like the RC remote/transmitter mentioned by AndyUK in the tutorial?

[Radu_Andrei]

I think the easiest thing is to use a wireless ps3/4 controller, as it has all the buttons I need, even 4 extra, and you never know what other functions I might add.
I don't know if it is worth it, or it is cheaper to build from scratch a remote with 16 buttons (in what ever format they might be).