Raspberry Pi Forums

Hi

My friend and I are joining the world of PI.

I am looking build a robot of some time, he is looking to build a RC Tank.

Both items require multiple motors (He already has a broken tank which has 5 motors)

I looked at a L298N Board but that appears to only support 2 motors.

Can anyone point me in the right direction to the best boards and why for multiple motors.

I will also be looking at adding some LEDs so ideally dont want to use up all my GPIO ports.

Thanks in advanced.

Hi

Sorry not heard anything.

I have looked at an
L298N board which only controls 2 motors

We are looking to control
2 DIFFERENT LEDs
8 DC Motors
USB Webcam

Can someone suggest which board to use with Raspberry Pi 2?

I would love to see a blog of the different boards.

Regards

Jamie

The board to use will depend on the motors.

Hi
These are standard DC Motors found in most RC Cars.

Similar to
http://www.mind.ilstu.edu/curriculum/me ... cmotor.jpg

- What kind of LED's?

- How many of the 8 motors need bi-directional (forward, reverse) control?

- I suggest the Raspberry Pi Camera instead of the USB Webcam

teuma86 wrote: 2 DIFFERENT LEDs
8 DC Motors
USB Webcam

I'm planning out a similar project, and my current plan is to use some transistors as relays/switches for the motors, and trigger the transistors using some GPIO outputs and play with PWM for throttling.

I believe standard LEDS (5mm)

Trying to work it out. This particular model for the tank has 5 motors but my project I am looking at 8, yes ideally bi-directional

Tank motors
2 to drive (Left and Right)
1 Move torrent around
1 Moves torrent up / down
1 fires gun (not seen this motor but i believe this can be one direction.

Ok, sounds like you need four bi-directional motor drivers, and one uni-directional motor or solenoid, depending on how the gun is fired.

For the four bi-directional motors:

Each motor will require 2 or 3 I/O's, depends on type of motor driver.

EN, DIRA, DIRB - requires 1 PWM, 2 I/O's per motor
EN, DIR - requires 1 PWM, 1 I/O per motor
DIRA, DIRB - requires 2 PWM per motor

so you require 4 - 8 PWM's and 0-8 additional GPIO's depending on motor type.

You will also need:

- 2 limit switches for turret up/down
- 2 limit switches for turret turning

for an additional 4 I/O's

Plus one I/O per LED.

You need to find out the voltage and stall current of the motors in the tank, so you can select an appropriate dual H-bridge driver board.

Models A & B would likely not have enough I/O to do what you want, an A+ / B+ / 2 should work, with joan's pigpio library, and appropriate driver boards.

Two L298N or three modules should work, if the motors do not require more than about 1.5A current during normal operation.

Or, if you want a lot more I/O, you could use a RoboPi in addition to your Raspberry Pi (see http://RoboPi.com)

teuma86 wrote:I believe standard LEDS (5mm)

Trying to work it out. This particular model for the tank has 5 motors but my project I am looking at 8, yes ideally bi-directional

Tank motors
2 to drive (Left and Right)
1 Move torrent around
1 Moves torrent up / down
1 fires gun (not seen this motor but i believe this can be one direction.

Thanks mikronauts

Please can you explain the Abbreviations. I am a web programmer, learning Pi and by the looks of it, in the deep end.

So my initial instinct of to purchase multiple L298N boards. I have seen multiple alternatives, just curious if one was better than the other.

I shall order multiple L298N boards
http://www.ebay.co.uk/itm/L298N-Stepper ... 43d12bba8a

You are welcome.

EN = enable
DIRA = go in one direction
DIRB = go in other direction

on other type of controller

DIR = 0 - go one direction
DIR = 1 - go in other direction

teuma86 wrote:Thanks mikronauts

Please can you explain the Abbreviations. I am a web programmer, learning Pi and by the looks of it, in the deep end.

So my initial instinct of to purchase multiple L298N boards. I have seen multiple alternatives, just curious if one was better than the other.

I shall order multiple L298N boards
http://www.ebay.co.uk/itm/L298N-Stepper ... 43d12bba8a