Me and classmates must build a robot that must do several things with motors. The thing is, I never built one and never used small DC motors. Also, our robot design is still in progress but we would need information to know what we could do and what we couldn’t do considering we have a maximum of 4 AA batteries (1,5V each).
So basically, I would need a chip. I looked on Arduino’s website, saw different products, but I don’t know what would be the best for the project. I was thinking Arduino Due would do considering the voltage limit.
The robot must be able to move forward and backward. Obviously, we need a motor for that, but what would be the best? Regular motor, servomotor, stepper motor? I never used any of these.
Also, we have to run a few motors connected to mechanical structures. For example, the robot must reach and grab a ping pong ball, carry it and then drop it in a certain space. Would a regular motor be fine or do we need a servomotor/stepper motor? We plan to have around 7 motors max, will certainly be less.
But let’s say we want it to move forward for a certain amount of time (we would do many tests to know where the robot would be after that amount of time) so that would place it in a certain position and then stop. We would need a chip and a gear motor to do that right?
Our robot will weigth around 3kg (6lbs), would the gear motors you mentionned earlier fit? And what about voltage regulator? We would use these to lower the voltage from 6 to 5V? Would the chip work with that? Because we have 4 AA batteries and there is no flexibility with that.
If you are new to robotics, we suggest Arduino. If you are new to electronics, we suggest the ROMEO (Arduino-based). This allows you to control two small DC gear motors, connect to sensors, and operate small servo motors which you can use to create a robotic arm with gripper. The price is very competitive. Note that most microcontrollers are powered from 9-12V, so if you absolutely need to use 4xAA batteries, you’ll need a voltage regulator.
You would need a “chip” (microcontroller is preferable since it is a complete circuit), a pair of gear motors and a dual (or two single) DC motor controllers. If you want repeatability, you would also need encoders.
Our robot will weight around 3kg (6lbs), would the gear motors you mentioned earlier fit?
You’d be best to choose a decent sized motor like the GHM series spur gear motors. The low cost / low voltage DC gear motors are primarily for <500g robots, though if you are restricted to 4xAA batteries, you may not have another option. Why would the robot weigh 3Kg?
The system will need more than just 4.8V to 6V - to run the electronics, you will need at least 9V, and a voltage regulator is necessary. A pack of 4x AA batteries cannot output much current, so keep the robot as lightweight as possible - minimize the material for the frame (if you want it to “look good” - do that later) and only use lightweight materials.
We suggest starting with the minimum - a microcontroller (the ROMEO is still a great option), a small 2-motor gearbox, some small servos and some sensors - connect them properly and get these working separately (you have a lot of coding ahead of you), and then work on the physical design of the robot.
I forgot to say something pretty important though. The robot must be able to do all the things by himself. Once we drop it on the competition field, we cannot touch it or control it by any means.
This means all the actions the robot must do must be programmed I guess because we have no markers on the field. So we cannot say when the robot reaches a certain point, he detects it then starts a motor and…
Also, the field is inclined and we obvisouly need to stop at a precise position to grab the ball for example, so we were planning on braking with the motor. Would that be possible?
