So, taking lego technic from my son, and at home Arduino Nano began to combine these designers.
We will need:
- Lego Technic (kits 42029 and 42033)
- Arduino Nano (link to the board)
- DRV 8833
- 2 servo drives SG-90
- IR receiver
- gear motor
- 2 LEDs
- 2 resistors 150 ohms
- Capacitor 10v 1000uF
- 2 single row combs PLS-40
- 2 PBS-20 connectors
- Inductor 68mkGn
- 4 NI-Mn 1.2v 1000mA batteries
- Connector dad-mom two pin to wire
- Homutik
- Wires of different colors
- solder
- Rosin
- soldering iron
- Bolts 3x40 and nuts and washers for them
Step 1 assemble the chassis and drive axle.
You can assemble any chassis from Technic, anyway, it turned out like this.
There is only the problem of connecting the gear motor with the parts of the designer. I decided this as follows: put on the axis of the gearmotor a connecting sleeve and inserted a scrap of a match for fixation. For mounting the gear motor used metal plastic from an iron designer and a clamp. It turned out the following:
Next, we install the resulting design on the chassis using 3x40 bolts:
And put on the wheels:
Step 2 swivel wheels
To carry out the rotation took the servo SG-90. It is necessary to carefully drill, so as not to touch the internal parts, a through hole with a diameter of 3.2 mm or just cut with a clerical knife.
We insert the bolt into the hole made, and at the edges of the corners and fix with nuts:
On the servo shaft we put on a lever with a screwed part from lego:
And finally the swivel assembly:
We put on the chassis:
Put on the wheels:
Step 3 lifting gear.
To lift the bucket took a modified servo SG-90. The whole point of its modification is to remove the internal controller and solder the wires directly to the motor in order to make a gear motor out of the servo drive, that is, so that it can completely spin. As well as in the first servo, you need to make a through hole for mounting:
Install on the chassis:
Step 4 cab.
It is necessary to assemble a cab from lego technic from photographs:
Step 5 is an electrician.
Here you have to take on a soldering iron. For convenience, you need to solder everything on the circuit board according to the following diagram:
I think it’s worth explaining a little: you can take any low-power capacitor, you can also find an inductor of any kind, this is necessary to stabilize the voltage of the microcontroller. Resistors need to be selected for the LEDs used. I took an IR receiver from an old toy, but you can buy it at a radio store. If there is strong interference, add a capacitor to the IR receiver power circuit.
I got this:
We install Arduino Nano and DRV 8833 in their places:
And now we put the board on the chassis (removed the wheels for convenience):
For power I used 4 Ni-Mn 1.2v 1000mA batteries connected in series and wound with electrical tape. I glued them to double-sided tape under the rear cab lid.
Step 6 cab installation.
We connect the IR receiver, motors and diodes according to the diagram, put the cab on top of the chassis, fix the bucket (any bucket can be made):
Step 7 firmware.
I am programming in an Arduino IDE. First you need to fill in my firmware and through the terminal look at the remote control codes that you are going to use. You can take any IR remote control, for example, from a TV or DVD player. By clicking a button in the terminal we will see the code of the pressed button, write it down on a piece of paper. We do this with all the buttons on which we want to program the actions of the loader. Next, edit the sketch. We write down the codes we recorded for the necessary actions into it and flash it again.
Firmware
Loader video: