Help to a project

hello everyone

i have a project that I want to make.
i have a item that i want to drive forward until the item I close to a small wall made of plastik or metal, when its close to the wall the item needs to go back " reverse" no turning only strait lines forward and back.
the item need to go back to the docking station and stop so it needs to detect when its back.
one day after it needs to do the same thing again and so on.
It need a temp sensor so it can't drive if its under a certain.

the item have 5 motors, 4 to make it forward/reverce "drive backards". 1 motor that drive the same way alle the time on forward"back.

can anybody help me what to buy to make it? everything have to be as small as possible.
it has to be 5v-12v.

If it’s just moving forward and backwards, why does it. need so many motors.
How far is the distance ? speed?
Is it carrying a load ?

the item is running on a slide so just forward and back.
there will be a load not much.
the distance can be anything from 3-200 meters.
speed on the 4 wheels motor are not so fast but a lot of NM, 1 last motor have more speed and NM.

how does it detect when it is close to the wall and when it is back at the docking station?
give details of the sensors used?
do you require any sort of remote control/monitoring? e.g. WiFi, Bluetooth, etc?

that's what im asking for, I don't know what sensor and stuff I need.
in the future it needs to be controlled on a app to.

for distance you could use

  1. laser TOF sensors - various modules depending on distance
  2. ultrasonic sensor

if later you require app control would suggest an ESP32 has builtin WiFi, Bluetooth Classic and BLE, plenty of IO capabilities - cost about £7 in UK
how will you power the mobile device?

This post is lacking lots of numbers.
How close to the wall? How repeatable must the distance be? How small is "as small as possible?" How much load? How fast?

Taking liberties with your spec, all you need is the simplest Arduino, a motor drive and an optical sensor and about half an hour of coding.

But there are other ways to do it.

Is the wall always in the same place? Must this thing have wheels or can you drive it with a belt using a single motor?

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yes I know, but at this point its unknown what the speed is of the motor and the load.
the item is about 3kg.
as close to the wall as possible so 1-2 cm.
small as posible, is the smallere the better but at this point is doesn't matter, but at the end of the produkt is have to be as small as possible.
yes the item can have a belt and 1 or 2 motors. but the belt/wheel motor can not be connected to the other motor because the belt/wheel goes forward/back and the other motor goes the same way all the time.
so does the motor drive have 1 or 2 different output?
i all new with Arduino and coding.

you are probably looking at something along the lines of a VL6180X Time-of-Flight Distance
an alternative could be to place a magnet on the wall etc and detect it with a hall effect sensor

will the detectors, motors, etc be on the mobile device or the wall etc ?

Yes a magnet on the wall could be a way to do it.
All the sensors motor and stuff like that will be on the mobile device.
How far distance for the sensor to the magnet, do you know that?

I last use a magnet and hall effect sensor on an oscilating table to detect end of movment - I seem to remember less than a cm - probably depends on strength of magnet - I used a very small magnet

how will you power the mobile device? e.g. a battery?

I will take a look at it.
The item will be powered by a battery pack 5v-12v

probably be a good idea to have seperate battry packs for microcontroller and motors
motor switching can cause spikes on power lines which can reset or brown out the microcontroller if common power supplies are used

Could the "item" have a probe on the front that could activate a microswitch when it touches the wall? How fast will the item move forward? Backward? How fast will the "other" motor turn (RPM)?

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hall effect switches have the advantages of no mechanical moving parts and no "switch bounce"

No it’s not possible to have a probe in front.

@OP:

There are too many unknowns, especially for someone who has never used an arduino before. Here are my suggestions

  1. Decide on a drive system. It's on a slide, so decide if it needs wheels on the ground or can be moved by a belt or a cable.
  2. Figure out how much motor power you need to move that load (and the carriage) at the desired speed/acceleration. If you decide on wheels, don't forget that you'll probably have to carry a battery with you and you need to account for the battery's weight. Decide how long that battery needs to last. This is a huge advantage of a fixed motor and cable system: you can use AC power if it's available.
  3. Learn enough arduino programming to control the above moving back and forth. You need an arduino, suitable motor drive (depends on your motor) and a power supply. Since you mention future App control, I recommend starting with an ESP32 or other wireless-capable arduino.
  4. Decide on sensor. Microswitch, Hall sensor, retroreflective optical, etc. All basically interface the same way. Add this to your code.
  5. How will you determine when you're back at the docking station? Open item?

Doing this stuff one step at a time is far easier than trying to figure everything out at once. I build custom arduino-based systems for people. The most common situation I see is someone buys a bunch of hardware because they have a great idea, then sit there scratching their head trying to figure out how to make it all work. Small steps. Break it into stages and get each stage working one at a time is the way to go.

yes I know.
I find a item that's go forth and back on a remote, that item will I try to make automatic so no remote. the item has a belt, 2 motor, every thing works with the correct speed nm and so on, the only thing I will need is to make it automatic and put sensor on for the stop in the front and stop at docking station. the item is not Arduino only print card.
i have at home a uno board, motordrive, ultra sonic sensor, will that be enough to make it like I want?

[quote="have13, post:18, topic:1199586"].
a uno board, motordrive, ultra sonic sensor, will that be enough to make it like I want?
[/quote]

You’ll probably need a spec and requirements document… motor(s), a couple of power supplies and a block / schematic of the project.

Once those are done, you should work on small pieces of the program, eventually combining them into a working prototype.

A bit of debugging, rework, improvements and documentation so you can fix it next year.

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