Building a Home Inspection Rover - NEED HELP!

Community General Discussions
1

Hello everyone!

My ingornace in this relm is perfectly complete.  However, I have been tasked by my job to create a rover for home inspections in tight spaces.

Gratefully, it really is a simple project.  We want the rover to be remote controlled and we will mount a GoPro camera to the top to take pictures and send live feed to the inspector.

With those basics, here is what a complete noob has come up with for components:

Body and Motors:

http://www.banggood.com/4WD-WIFI-Crosscountry-Offroad-Robot-Smart-Car-Kit-For-Arduino-p-927973.html

(This kit does include a Wifi system that is NOT explained at all.  I worry about range.  I need about 60-100 feet [20-35 meter] range.)

Motor Driver:

https://www.robotshop.com/en/sabertooth-dual-12a-regenerative-motor-driver.html#reviewBox

(This link shows the wiring recommended for 4 motor units:http://www.lynxmotion.com/images/html/build123b.htm)

R/C Transmitter & Receiver:

https://www.amazon.com/FlySky-Channel-Digital-Transmitter-Receiver/dp/B00KHJ262Y/ref=sr_1_6?s=toys-and-games&ie=UTF8&qid=1488987040&sr=1-6&keywords=rc+transmitter+and+receiver

Batteries:

12V : http://www.lynxmotion.com/p-727-120-volt-ni-mh-2800mah-battery-pack.aspx

6V : http://www.lynxmotion.com/p-331-60-volt-ni-mh-1600mah-battery-pack.aspx

Maybe not these exact ones but with same specs.

Pan and Tilt For Camera:

http://www.lynxmotion.com/p-287-lynx-b-pan-and-tilt-kit-black-anodized.aspx

LED Lights:

Not sure how to do this at all.  If someone has some guidance, we need a lot of light.  Help and pointers would be very appreciated.

 

Based on your knowledge, do you think these components would go together well (do their specs match)?  I know NOTHING about electrical ratings, specs, etc.  Do you see anywhere where this design would fall short?  Any advice or pointers?

 

One last question: how long do you think this unit would run before needing charge?

Thanks everyone!

2

Sounds cool!I’m not an

Sounds cool!

I’m not an expert, just a dabbler, but just giving my 5 cents.

You motor driver seems slightly overkill to me, as smaller would do, but I don’t see why it wouldn’t work.

I’m curious though on what kind of output R/C receiver has, whether the logical signal is HIGH/LOW or PPM/PWM, as the latter would give options for fine control. Also, I’d be interested in receiver’s output voltage, if it matches with motor driver’s input voltages. My guess is that 3 - 5V HIGH is somewhat of a standard, but I’m not an expert.

How would Lynx pan & tilt work with GoPro - no idea. Probably no problem, but maybe you need to drill some extra holes? Also, GoPro is pretty light, so probably that servo has enough power to turn it. You should need a servo motor driver for the pan & tilt, right? And then it’s quite crucial what kind of signal your R/C receiver gives out - you might need a microcontroller.

Led lights, there are plenty of options for leds with reflectors, but finding something that is easy to mount is a different issue. What kind of light you need is an important question - lots of flood light or precise spotlight? I’ve wired some led torchlights to batteries, and for me it’s been the easiest way as I get reflectors and proper resistors without hassle, but perhaps there are ready-made modules too.

Guessing that your batteries will run for quite a long time. I might be totally wrong, but I’ve been able to run small motors for hours with similar power.

3

As the motor controller you

As the motor controller you might use 2 of these : https://www.robotshop.com/en/tiny-v2-esc.html 12 Amp max. is totally overkill.

For the servos you then need a step down converter like this one (Then you don’t need an extra battery for them) : http://www.ebay.com/itm/Waterproof-DC-DC-Step-Down-Voltage-Regulator-12-24V-to-5V-Buck-Converter-Power-/262204896645?hash=item3d0ca13585:g:txoAAOSw~otWemQr

You should be able to control the servos for pan/tilt with the rc remote with airplane settings. You can mix the channels of one stick to get a tank control so pushing the stick forward makes both motors turn and when leaning it left/right you offset the speed so you make a turn. The second stick you can use for pan/tilt. https://www.rcgroups.com/forums/showthread.php?2579971-Wanted-RC-tank-transmitter-programming-for-Dummies (ask me if you need help).

But you can also go with the overpowered one so you can change the motors in the future if the old ones are not strong enough and you wouldn’t need a seperate step downconverter for the servos and the receiver. (moreover you get a really solid motor driver)

The battery : I think you will get problems with that. It says : “Max discharge current: 2.8A” so assuming 4 motors with 0.5 A each and 2 servos with approx. 1 A each would be 4 A in total plus the receiver and the ESC’s. You should better use a Li-ion battery with similar capacity since they can provide much higher current. (For comparison : https://www.robotshop.com/en/li-ion-2200mah-battery-pack-31012.html)

I hope that helps.

4

You are both awesome!

You are both awesome!  Thank you so much for your feedback.  This is an evolving process and you are making this possible.  So thank you.

2 Things:

1)  The motor control (you both mentioned this):  what if we went with this one instead:

https://www.robotshop.com/en/sabertooth-2x5a-rc-driver.html

https://www.robotshop.com/en/sabertooth-dual-5a-motor-driver.html

This addresses the over powered ampage.  5A on this.  This would also address your comment Opidopi…this controller is plug and play and offsets speed etc. (I think)

Once again, this is just something else I found that might be a good option.

2)  Battery:  This is where my knowledge is weakest.  I don’t understand voltage and amps well at all.  This battery is interesting though:

https://www.robotshop.com/en/12v-9500-mah-ni-mh-rechargeable-battery.html

I like the high hours on this.  We  need these units to run for a while.  It does state that the continuous amp output is 9.5.  I have no clue how that would have an effect on the driver/motors etc.  Any feedback would be deeply appreciated.  

3)  The camera:  We are no longer using a GoPro.  It’s live feed preview is only 240-480p  max and we need HD resolution to pick out details during inspections.  We are working on this…more of just an FYI.

Thanks for your further help everyone!

 

5

The first motor driver looks

The first motor driver looks good you can set it to mixing mode with the switches. The second one doesn’t have the leads.

The battery also looks good 9.5 A should be enough and 9.500 mAh should runyour rover over an hour. The continuous amp output means how many amps it can provide to your motors and servos. For example if your motors need 1 A at 12 V and you’ve got four your battery should provide at least 4 (Actually more because when starting to roll they need more amps). If your battery can only provide 3 A you loose torque and servos might jiggle and do not move to the specified positions. You might also lose connection when your receiver doesn’t get enough power.