Welcome to Synthiam!

The easiest way to program the most powerful robots. Use technologies by leading industry experts. ARC is a free-to-use robot programming software that makes servo automation, computer vision, autonomous navigation, and artificial intelligence easy.

Get Started
Asked — Edited
Resolved Resolved by rz90208!

Rad Robot With Ezb-V4


I'm a bit lost and need some help.

I'm trying to convert an old RAD 1.0 robot to run as a remote viewing robot.

I have the existing servos connected through H bridges to D4 and D5.

I have three questions:

1 - I think I'm getting brown outs from too much power demand. Should I use an NPN transistor to deal with this?

2 - I have not been able to figure out how to get the motors to work with the arrow keys.

3 - Is it possible to install a microphone? I assumed the camera would have audio but there does not appear to be any.

Any help would be much appreciated.
-Saba in LA

User-inserted image


Upgrade to ARC Pro

Synthiam ARC Pro is a cool new tool that will help unleash your creativity with programming robots in just seconds!



1 - I think I'm getting brown outs from too much power demand. Should I use an NPN transistor to deal with this?

We'll need more information for this one. What is your power source? Same power going to the EZ-B and hte H-Bridge? What voltage, what amperage, etc....


2 - I have not been able to figure out how to get the motors to work with the arrow keys.

I assume in my answer that you have the H-Bridge control in your project and configured and can use the mouse on the arrow buttons of the control. If this is the case, click your mouse in the black box that says "click to use arrow keys", and then the arrow keys will work. If you click an object outside of the movement panel, the arrow keys will stop working (although things like joysticks or other controllers will still work).


3 - Is it possible to install a microphone? I assumed the camera would have audio but there does not appear to be any.

Neither the EZ-B or the camera have a microphone. ARC expects to use a microphone recognized by your computer. The recommendation is to use a bluetooth microphone or headset if you aren't near the computer. Keep in mind that the robot may be quite noisy when moving, so having a microphone actually on the robot may not be very effective.

One point about your comment I want to clarify. Your robot has servos you installed correct? Becaus the original rad robot didn't have servos, only motors, which might be a problem if you connected them to the ez-b directly.
Wow both these comments help so much.

I know so little I thought servos and motors were synonymous and I could connect motors directly.

Where to start. I will post my system details here next.
That is why I wanted to check. Servos are generally rectangular with 3-4 wires coming from them. The rads motors are dc brushed motors, so they will have 2 wires.

To control the rads motors, which are in the drivetrain, waist, arms and gun I believe, you have to purchase some motor controllers, such as the l298 (2 motor driver) off the store. You then follow the procedure to hooking your motors up to them, and them to the ez-b. This should solve the burnout issue quick.

If your only concerned with the drive train, there are only 2 motors, so 1 motor controller should work. I have a rad that I modified heavily,(and quite frankly, terribly) so I can give you some pointers.

First of all I really appreciate everyone's time and help.

My original goal was to use the EZB developer kit to convert an original RAD 1.0 to a tele-presence robot to interact with children. I was surprised to learn that there was video but no sound supplied with the kit. This effectively negated the utility as a TP robot but I thought I would work on the rest and come back to the audio issue later.

My first modification was to remove the 6V battery and replace it with a 7.4V 2 cell LiPo (Venom 2000 20C). I installed the battery and the battery charger in the base of the unit so all the kids would have to do is plug in the robot, not move a battery to a charger. I believe this conversion is ok but it may not be a great idea to have the battery permanently connected to the charger. For the moment I'm using a 7.5V 0.9A power supply.

Once I received the EZB kit I was hoping to replace the old motors with the new servos but found that due to the size and the gears I could not swap them so I decided to keep the original motors. (For this conversion I have eliminated the arm motors and the hip motors, leaving only the two motors that turn the treads for movement).

When I saw the EZB servos had three wires, not two, I did open that EZB continuous servos and I saw that there were boards between the power leads and the motor itself and when I probed them they appeared act as H-bridges (I could be mistaken here). So I harvested these boards and moved them to the original motors. They appear to work if now at a higher voltage of 7V instead of the orginal 5V. I thought this might be ok.

I have mounted the camera in one eye and a cree LED in the other eye with the 4 existing LEDs in the robot face all connected to the EZB brain because I eventually I wanted to program a larsson scanner effect like the toasters on BSG...

Currently the Digitals are connected:
D0 Red LED Head
D1 Red LED Head
D2 Red LED Head
D3 Red LED Head
D4 L Tread Motor
D5 R Tread Motor
D8 Cree LED Head
D9 Cree LED Head
User-inserted image

User-inserted image
If I understand you correctly, You removed the small circuit board from the servos and plan to use them to drive the Rad motors?
If so, the boards wont last long. They are not designed to handle the amount of current those motors will draw. An ezb H-Bridge board or a third party board is your best bet.
Thank you for the feedback.

I will upgrade and try again.
In my RAD v1, I use an Arduino uno and an Adafruit motor shield. The shield handles all 4 motors and a servo for the neck. (This bot was built before I got my first EZB).
I took out the chest gun and mounted a speaker there.
I was working on replacing the head with a 3DPrinted head that will hold a Samsung cell phone.
But now after using the EZB, I plan to convert it all over to the Small EZB board when it comes out.