I am not an expert and new to arduino. However i have basic software and electronic skills.
I would like to mod my son RC car to have indicators. I wired everything up and fit leds. My plan is to throw in arduino pro mini and power it using same 5X AA batteries currently supplying the car. to achieve this i need to take voltage measure from the front motor which turns the front wheels right and left to automated the process of signal indication. However the front motor is giving only minor peak voltage and then drop on inconsistent readings after less than second.
what i want to do?
Taking voltage reading from both motor wires (Left+Right) in order to automated the signalling operation with the proMini. (I would attached each leg to analog pin).
But i could not figure out a way to do it. Any help is appreciated.
I attached photo of the CB for the car as well as the motor, Note: that both legs for the motor are attached to resisters with ceramic capacitor in between.
Is this a really cheap and simple car with what I would describe as ON/OFF steering or does it have proportional steering? And if it has proportional steering does it use a servo or a DC motor?
Am I correct to assume that at the moment you do not plan to use the pro-mini to control the steering?
Thanks for your note about attaching photos in which its contents has been noted.
From when i have seen after disassembling the front part, its a simple motor that drives a set of gears in order to steer the car. I am not sure what is the servo is ?
I attached the photo here. I was hoping to get some voltage measurement from the motor cables in order to instruct the arduino to indicate the leds upon steering left and right. anyway to do that?
In your picture of the motor I don't see any evidence of a position feedback system that would allow the steering to be moved say 10° or 20° rather than just moving to full lock.
If the car's controller is sending a PWM signal to the motor (which is quite likely) it will appear as a series of ON/OFF pulses and there is no guarantee that an Arduino would take its measurement at the HIGH point.
Do you have a GND connection between your Arduino and the car's control system - that will be essential. But equally essential is to ensure that the signals from the car stay strictly between 0v and 5v on any Arduino pin. And electric motors are notorious for generating high voltage pulses.
Have you considered putting some sort of switch or optical detector that is triggered by the car's steering mechanism?
Yes I get it now. Yes it appears that it is a servo what is attached to the attached.
In your picture of the motor I don't see any evidence of a position feedback system that would allow the steering to be moved say 10° or 20° rather than just moving to full lock.
There is postioning arm underneath the gears, which appear to do exactly moves 20 degree both direction
If the car's controller is sending a PWM signal to the motor (which is quite likely) it will appear as a series of ON/OFF pulses and there is no guarantee that an Arduino would take its measurement at the HIGH point.
That is exactly what sort of reading i get. Fluctuation readings.
Do you have a GND connection between your Arduino and the car's control system - that will be essential. But equally essential is to ensure that the signals from the car stay strictly between 0v and 5v on any Arduino pin. And electric motors are notorious for generating high voltage pulses.
Yes ground point is same for arduino and CB. Yes max vault on all positive points on the CB is around 4.2V.
Have you considered putting some sort of switch or optical detector that is triggered by the car's steering mechanism?
No, I do not know about this, if such thing is exist then my problem is solved. Please recommend options as this will solve all my problems, I just want something that the arduino can use to detect the right and left steering. or if i could read PWM single using arduino this is will also help.
haggar11:
Yes I get it now. Yes it appears that it is a servo what is attached to the attached.
Now I am totally confused. Your 1st picture in Reply #3 is nothing like a servo.
There is postioning arm underneath the gears, which appear to do exactly moves 20 degree both direction
Is that the arm that moves the steering or an arm that sends data back to the car's controller?
That is exactly what sort of reading i get. Fluctuation readings.
You could get your Arduino program to check for pulses, rather than a consistent HIGH reading. If there are pulses it probably means the steering motor is being driven. If the interval between pulses is too long then the motor is not being driven.
No, I do not know about this, if such thing is exist then my problem is solved. Please recommend options as this will solve all my problems,
Hey, C'mon now. You need to do a little of the work. Google "slotted optical switch", "reflective optical sensor" and "microswitch"
I have just realized that you are now pursuing the same question in two other Threads here and here.
I have no intention of jumping all over the place to find out what answers have already been given so that I don't duplicate them. Keep all the stuff for one project in one place.
