Asked — Edited

Ways To Add More Servo Ports?

Hello! I've been building a humanoid robot (ready for a EZ-B v4!) and i was wondering if there was any way to add more servo ports to the EZ-B. I'm going to have to use up all 24 servos for just body movements (each arm has 5 servos, and each leg has 6) and i want to add some sensors/more servos. I've been looking at this: and i was wondering a couple things.

  1. How much coding does this require? (if you know) I'm absolutely horrible at coding.

  2. Are there any easier alternatives?

  3. If some coding IS required, where can i find resources to learn how to code?\



Upgrade to ARC Pro

Unleash your creativity with the power of easy robot programming using Synthiam ARC Pro


There is no coding required for additional servos. You can link EZ-B v4's together, up to 200 of them. Which means you can have a total of 4,800 servos.

Even the previous EZ-B v3 version allowed 5 to be connected at once.


I only ordered one, sadly. I also dont have the funds right now to get two, which is why im asking.


As far as movements go you can make frames with auto position. Look at the RoboPhilo project. The 2nd vid shows the AutoPosition function. (The vids are a little old so the screen layout is a little different but it still functions the same. Rumor has it new vids are coming soon:) )

RoboPhilo and EZ-B


I'm aware of the auto position, but thanks antron. I'm just asking for any ways to expand my servo ports without buying a second EZ-B v4.


So DJ, would the EZ-B recognize the added ports from the SD20 chip or no?


I may be mistaken but I think they make what they call relays and you can control the relay with one port and send it commands it uses to control the servos. I'm fuzzy on it but I'm sure I've read something about it somewhere and I want to say on this site. I think they usually use serial communication. But it seems a little simpler than that chip you linked to. I wish I could remember more but unfortunately it's not a problem I've had yet. :)


So I will have to order another EZ-B v4 to add more ports without coding?


Without coding, yes, you would need another board.

If you are OK with Bluetooth instead of WiFi for the second board, you may be able to buy a used V3 board for less than the v4. In fact, I have one that has never been used except to boot up and load the latest firmware to confirm it works. I would want to get out what I put into it, which was ~$70. Email to if interested.


United Kingdom

You will need another EZ-B if you want to add more ports and have them supported natively by ARC.

There I2C Expanders (like the SD20) but to be honest I've not found any which are that easy to use so you're pretty much taking the EZ out of your EZ-B. They would require scripting to use and none of the controls in ARC would see the additional ports. All commands you need to be sent via the I2CWrite() commands in EZ-Script.

If you are going down that route Adafruit do a 16 channel 12 bit PWM/Servo Driver which is I2C controlled. It's datasheet is here. I got one to try but I didn't get far with it to be honest.


thetechguru is a good guy. He's sent me some things before so you can trust him if you're interested in that board.