Car Helicopter Prototype

[Sharkbite]

Hey all, I'm really new to electronics. I know some, and still need help

I want to build a car that also functions as a helicopter. I'm planning to use a 4ch transmitter. So my question is, is it necessary to use a micro controller? I've watched a lot of videos and read quite some articles. I can somehow make it work without a MCU, but is it necessary to put it in?
Thanks, I appreciate replys

 

[jpanhalt]

Welcome to ETO.

This sentence doesn't make sense to me: " I can somehow make it work without a MCU, but is it necessary to put it in? "

Do you mean you can make it work with (not "without") an MCU?

Your receiver will have an MCU in it most likely. So the simple answer is, no, you cannot make it work without an MCU. However, given that you have a working RF link with enough channels, you can fly a helicopter without an additional MCU. As for the car part, that will not require an MCU, but you may need additional channels.

Can you draw a block diagram of what yo are thinking of doing?

John

 

[Sharkbite]

I can make the prototype work without a micro controller. I'm just asking is it necessary to use a MCU?

 

[rmn_tech]

Well if you can make it work without an MCU (micro controller). Then it seems obvious to me and anyone else with a brain, That it's not necessary to use an MCU.

I don't mean to be patronising but your question makes no sense.

 

[Sharkbite]

I'm using a 4ch transmitter. It is originally for my old helicopter, but I want to use it for this project now. I've bought the ex and tx crystals for this project

My idea is that the : (note. This is a reversed remote, thrust is on the right)

Left joystick :

when forward: car goes forward
Back: car goes backward
Left: left
Right: right

As for the right joystick :

When thrust is pushed, propellers turn and lift the car up. When this happens, IR sensors tell the car that it's in the air and it switches to helicopter mode. When this happens, the left joystick changes function.

Heli mode:

when forward: car (heli mode) goes forward
Back: car (heli mode) goes backward
Left: left
Right: right

My main problem is that I need to know if:

1. It's possible to connect the receiver to MCU? If so how?
2. What do all the pins on MCU do?

And of course advice on this project

 

[Sharkbite]

Well if you can make it work without an MCU (micro controller). Then it seems obvious to me and anyone else with a brain, That it's not necessary to use an MCU.

I don't mean to be patronising but your question makes no sense.

I'm asking, will it be better using a MCU?
I'm willing to use it, but how can I connect it to receiver?
Will it be messy if I don't use it?

 

[Sharkbite]

Sorry, If my tone sounds a little too far off

For the car, I have a question.

I'm going to use the 4ch receiver. One port (thrust) goes to the ESC.
The other ports are for servo's. If I connect a AC motor to the servo port, will the motor spin forward and backward based on the transmitter?

 

[rmn_tech]

Ok now I understand. Your original question sounded wrong e.g. It works without do I need to use one?

Now I see you meant. Would using an MCU Improve or even simplify the project. IMHO I would say that it would simplify the control unit but you would need someone more advanced with MCU's to help more.

As I said sorry for sounding patronising but I was misunderstanding your OP.

Rick.

 

[Sharkbite]

It's alright it, thanks on your opinion rick...

 

[large_ghostman]

a mcu wont do a thing, it dosnt matter what pins you connect it will sit there like a brick.
to explain
a MICRO CONTROLLER (mcu) has to be told what you want it to do by programming it, you cant just buy one stick it in and off you go, for your project you would need to program the chip to do exactly what you want, or get someone to do it for you. would it be worth it????? HMMmmmmmmm i am micro obsessed so i am biased but i would say it's a great project for a micro and you could get it to do all kinds of things even down to putting a ultra sonic TX/RX in it so if the copter starts to descend too fast the micro will apply power for a softer landing, actually you could program a beginners mode so the micro helps fly it if you added a accelerometer! so yes on one hand a micro would be great but you dont have to use one

 

[Sharkbite]

a mcu wont do a thing, it dosnt matter what pins you connect it will sit there like a brick.
to explain
a MICRO CONTROLLER (mcu) has to be told what you want it to do by programming it, you cant just buy one stick it in and off you go, for your project you would need to program the chip to do exactly what you want, or get someone to do it for you. would it be worth it????? HMMmmmmmmm i am micro obsessed so i am biased but i would say it's a great project for a micro and you could get it to do all kinds of things even down to putting a ultra sonic TX/RX in it so if the copter starts to descend too fast the micro will apply power for a softer landing, actually you could program a beginners mode so the micro helps fly it if you added a accelerometer! so yes on one hand a micro would be great but you dont have to use one

Thanks bro, actually I wanted to do it that way, I mean if it accidentally falls, it can control itself.
Plus if possible if the receiver suddenly loses connection to transmitter, the mucus can provide a program to land it safely to base. If it spirals out of control, there will be a program to assist it.

I want to do the programming myself, but generally I don't know how. That's why I'm asking is it worth putting it in there?

If I put it in, sure it can do amazing stuff, but how do I connect it to its inputs and outputs?

 

[jpanhalt]

My main problem is that I need to know if:

1. It's possible to connect the receiver to MCU? If so how?
2. What do all the pins on MCU do?

And of course advice on this project

Thank you Sharkbite for the additional information. Your comments are quite useful toward understanding what you want to do.

First, you mention propellers (plural). Are you referring to just the front and rear rotors of a typical helicopter, or does your helicopter have more than one main rotor, such as a quadracopter?

Second, yes, the receiver can be connected to the MCU. In fact, I doubt very much that you want to connect the MCU directly to the RF side. The output from the receiver is a typical pulse-width servo control signal on each channel. (I am assuming your transmitter does not have servo mixing built in.) So, each stick movement will control a single channel. The outputs have 3 wires, one is for ground (usually brown or black), one is for V+ (usually red and almost always the center wire), and one is for signal (usually yellow, orange, or white). From hereon, when I say "connect," I am referring to the signal wire only. Your MCU will, of course, have to share a common ground with the receiver. Those outputs could be combined to a single, serial input to the MCU, but an easier way to begin with might be to connect each signal wire from the receiver (i.e., 4 wires) to a separate pin on the MCU.

The MCU will need to be programmed to adjust its outputs to the mode (car or flight) that it detects. You will need at least 4 pins on the MCU for outputs. I suggest you make a flow chart to help get started. So long as you use 4.8 V (nominal) for the receiver power supply, you will not need any voltage translation between the receiver and MCU.

John

 

[large_ghostman]

if you want to program yourself its a long road! but sometimes people get lucky and someone offers to help, i am not an expert i am still learning about MCU's i use pics (a mcu from microchip)one thing i did think of is if you can find someone willing to help with the code then you could use a pic with a bootloader (special code in the chip so you can load another program in via serial or usb) and then all they need do once you have the chip with bootloader is send you the file each time its modified and you can then use a special program to load it and test it.
i would love to help but the kind of code your talking about is above what i can do at the moment, shame because its the sort of thing thats got loads of learning potential. if you want to buy a programmer and get into it yourself then be prepared for it to take 12-18 months minimum if you work hard to get it somewhere near where you want. But man you could do some neat stuff with a micro on a project like that! if your still looking in a year i might be upto scratch by then ,
GOOD LUCK its a ace project

 

[Sharkbite]

Thanks ghostman I'll try my best

 

[audioguru]

You have an old-fashioned radio system. It operates on a single channel that is at 40.685MHz. Its antenna is long and if anybody else uses that same channel then both of your helicopters will have interference and will crash.

Modern radio control operates at around 2.4GHz. The antennas are very short and there are at least 40 channels that are automatically selected for no interference.
To avoid additional interference, when a model is first used its receiver is "bound" to the transmitter and using a unique "Global Identity" so that only your transmitter will activate the receiver and no other transmitter can even if it uses the same channel.
Of course digital proportional control is used for very fine adjustments of the model.

Most of my RC airplane and helicopter models use 3 gyroscopes to keep them level if wind gusts try to flip them over. Their flights are very stable but acrobats are not affected.

 

[Sharkbite]

Thank you Sharkbite for the additional information. Your comments are quite useful toward understanding what you want to do.

First, you mention propellers (plural). Are you referring to just the front and rear rotors of a typical helicopter, or does your helicopter have more than one main rotor, such as a quadracopter?

Second, yes, the receiver can be connected to the MCU. In fact, I doubt very much that you want to connect the MCU directly to the RF side. The output from the receiver is a typical pulse-width servo control signal on each channel. (I am assuming your transmitter does not have servo mixing built in.) So, each stick movement will control a single channel. The outputs have 3 wires, one is for ground (usually brown or black), one is for V+ (usually red and almost always the center wire), and one is for signal (usually yellow, orange, or white). From hereon, when I say "connect," I am referring to the signal wire only. Your MCU will, of course, have to share a common ground with the receiver. Those outputs could be combined to a single, serial input to the MCU, but an easier way to begin with might be to connect each signal wire from the receiver (i.e., 4 wires) to a separate pin on the MCU.

The MCU will need to be programmed to adjust its outputs to the mode (car or flight) that it detects. You will need at least 4 pins on the MCU for outputs. I suggest you make a flow chart to help get started. So long as you use 4.8 V (nominal) for the receiver power supply, you will not need any voltage translation between the receiver and MCU.

John

Yes, john, it has 4 main rotors that will be controlled by an esc. You must esculent me, sorry, I'm off to bed now, good night. I'll catch up in the morning

 

[Sharkbite]

You have an old-fashioned radio system. It operates on a single channel that is at 40.685MHz. Its antenna is long and if anybody else uses that same channel then both of your helicopters will have interference and will crash.

Modern radio control operates at around 2.4GHz. The antennas are very short and there are at least 40 channels that are automatically selected for no interference.
To avoid additional interference, when a model is first used its receiver is "bound" to the transmitter and using a unique "Global Identity" so that only your transmitter will activate the receiver and no other transmitter can even if it uses the same channel.
Of course digital proportional control is used for very fine adjustments of the model.

Most of my RC airplane and helicopter models use 3 gyroscopes to keep them level if wind gusts try to flip them over. Their flights are very stable but acrobats are not affected.

Thanks on your opinion audioguru. I have realized that there is 2.4ghz remote, unfortunately it's a little too expensive for me. It's about 80USD in my place. Furthermore, I'm new to building robots. All I've done is mostly research. I read about micro controllers, servos, ESC's, etcetera...

To put in short, I understand about parts, but I've never tried with them. That's why I thought I'd rather try with my old transmitter first

 

[Sharkbite]

Thank you Sharkbite for the additional information. Your comments are quite useful toward understanding what you want to do.

First, you mention propellers (plural). Are you referring to just the front and rear rotors of a typical helicopter, or does your helicopter have more than one main rotor, such as a quadracopter?

Second, yes, the receiver can be connected to the MCU. In fact, I doubt very much that you want to connect the MCU directly to the RF side. The output from the receiver is a typical pulse-width servo control signal on each channel. (I am assuming your transmitter does not have servo mixing built in.) So, each stick movement will control a single channel. The outputs have 3 wires, one is for ground (usually brown or black), one is for V+ (usually red and almost always the center wire), and one is for signal (usually yellow, orange, or white). From hereon, when I say "connect," I am referring to the signal wire only. Your MCU will, of course, have to share a common ground with the receiver. Those outputs could be combined to a single, serial input to the MCU, but an easier way to begin with might be to connect each signal wire from the receiver (i.e., 4 wires) to a separate pin on the MCU.

The MCU will need to be programmed to adjust its outputs to the mode (car or flight) that it detects. You will need at least 4 pins on the MCU for outputs. I suggest you make a flow chart to help get started. So long as you use 4.8 V (nominal) for the receiver power supply, you will not need any voltage translation between the receiver and MCU.

John

Thanks john, just a simple doubt, does the mc need ac or dc current? What type of mc is easy to program?

 

[jpanhalt]

The MCU needs DC current. The common ones I have seen operate on low voltage, such as 5 or 3.3 volts.

As for easy of programming, the actual process of writing the program to the MCU is easy, but may require a programmer. Learning to program varies with the individual. Check out the tutorials on ETO for programming in Assembly and C (Nigel Goodwin and Ian Rogers, respectively).

As for using 40 MHz instead of 2.4GHz, I would disagree with AG. About half of our club still uses the "older" American frequency of 72 MHz. It makes no difference in how the airplane flies. That depends on the pilot.

John

 

[audioguru]

As for using 40 MHz instead of 2.4GHz, I would disagree with AG. About half of our club still uses the "older" American frequency of 72 MHz. It makes no difference in how the airplane flies.

Does your club use 40.685MHz that Google says is used only in Europe for surface models?
Does a 72MHz transmitter/receiver detect that a channel is in use then automatically select another channel like happens on 2.4GHz?
Is a 72MHz model "binded" (bound?) to its transmitter like on 2.4GHz so that no other transmitter can interfere?