Asked — Edited
Resolved Resolved by Rich!

Looking For Connector Plug For V4 Uart Port

I'm Looking for a source for a connector plug for the V4 Uart port. Any ideas where I can get one? Depending on what type it is I may be able to squeeze the pins my self.


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I assume you mean UART port 0.... I just use male prototyping wire...

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It's the same as the old I2C port which I spent ages looking for a connector for.

In the end I used a 4 pin header with the short side soldered to 4 jumper wires and heat shrinked to form a kind of plug.


Sorry, edited my post here. I thought we were talking about a JSP plug and now see were not.


Yes, I do mean uart 0. The little black female port on the lower right side of the V4.

@RichardR, Those jumpers are exactly what I've been using so far. I was hoping to find someone who found the proper connector plug that would slip over this port and give a good firm connection. I don't really trust the flimsy connection that I have by just pushing one jumper end into the port at a time.

@Rich, I like your solution. At least it gives kind of a connected and supported plug like connection. I had thought of doing that but was hoping for a commercially made plug.

I'm very surprised EZ Robot doesn't have a suggestion on the type of plug that can be used in this port. After all they designed it and should have a good solid and preferred way to connect to it. I had wondered about this with the old V3 and it's i2C port and I think I remember Rich starting a discussion about it now that you mention it.

Hopefully someone at EZ Robot can post here now and either tell us what to use to plug into this port or at least tell us they don't have any suggestions. Obviously we've found a way but I still hope there is a better plug available then the (in my opinion) inferior or homemade way we have been connecting.


@Dave... The problem is EZ Robot doesn't know what serial device would be used to connect to the UART 0 port... I mean since there are so many to choose from... What would the other end of the plug look like? Maybe just bare wires?

You could crazy glue or hot glue (kinda' messy with hot glue, though) your male header wires together to form a solid plug... Maybe even a little hot glue to keep it in place on the UART header too?...

Found these on eBay...4pin female/male header cable


Rich's idea about soldering wires to a header is a great idea. It's a simple and inexpensive way to make a good plug for either V3's i2C port or V4's UART port. Nice thinking Rich! It got me thinking of other ways to make a plug for these ports. I love using Molex connectors and have them around the shop along with the tools to use them for repairing my Pinball games. So I pulled them all out and started cobbling. I've settled on 0.1 right angle Molex circuit board header and a 0.1 Molex plug. Here's what I came up with:

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Here's a list of the parts: Connector, 0.1" Header, 9-Pin, Right Angle: Molex Part Number: 22-05-3091 Connector, 0.1" Plug, 10 Pin: Molex Part Number: 22-01-2107 Crimp Contact, 0.1: Molex Part Number: 08-52-0123 Keying Plug, 0.1: Molex Part Number: 15-04-9209 Cheap Crimping Tool: Part number: W-HT-1921 Expensive Crimping tool: Part number: 3135-CT

Have fun!


Thank you Dave for sharing, I am looking forward to my new EZB4. I have jumper wires ordered, but like your idea. Is the Molex crimping tool specialized or can I use a standard electrical crimping tool? Thanks, Steve S


@steve... You know you don't have to use UART port 0 (the one Dave is using above)... Pins 5,6 are UART 1 and pins 18,19 are UART 2.... So there is no need to spend money and fuss over a special cable and crimping tool unless you really have to...


Richard R, Thanks, I have so much to learn! You have experience that I appreciate! So many great people that I can relate to, like you, Dave, and many others.! EZ is the best! Steve S

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I like the right angled molex connector idea a lot, I may have to use that myself.

Another method I used on the I2C was protoboard and header pins to make a kind of Z type connector which converted the plug to pins (it even allowed for pull up resistors to be easily added and an LED to indicate connection (at least on the power) was OK.

By the way, I2C is pronounced a few different ways, I pronounce it as Dave did but I've heard it pronounced I Squared C also. And it's 3.3V just to clarify it, not that it matters:)


Thanks all. Glad you guys enjoyed the video. I did it if for no other reason then to show a few different options I've tried.

@Richard is right that you can use a couple of the Digital ports to send and receive serial commands. However if you start filling them up with other things that UART 0 port is mighty handy.

@Rich, thanks for adding to this thread with the useful information. Can you post a pic of that homemade Z connector you mention? Also thanks for clarifying the 3.3v v issue. I had a mind fart while filming and couldn't remember. However what's a few fractions of a volt among friends anyhow? ;)


I've been thinking about better ways to connect to the UART port. Although my Molex 0.1 plug is a solid way to attach to an inserted 0.1 straight or 0.1 right angle header, It's hard and expensive for the average person to buy all the parts and learn the technique of crimping the pins. Lucky most of us robot builders do have servo cables. After playing around with all this the past couple days I learned that the female end of common servo cable is an exact fit when plugged on to 0.1 header pins. So no need to gather all the parts I listed above and buy expensive tools. You can just plug your regular servo cables into the UART port.

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Of course if you use a common servo cable it only has 3 wires and you wont be able to utilize the 3.3v port. To do so you'd have to run an extra jumper wire, supply 3.3v power to your device externally or build a Molex connector plug like I did above.


Hello I think I found some breakaway header connectors that would help here is a link to a page of different ones

Breakaway headers


Nice find @Wolfie. Among the ones listed on that page the Extra Long Headers and the Right Angle Headers will work. The important thing is that both sides have to have long enough male pins to both fit fully down into EZB's female port and also be able to fully accept either a Molex plug housing or a servo cable on the other end.

Lacking any definite guidance from EZ Robot on the proper manufactured type of plug to mate with either the i2C port on EZ robot's V3 or the UART port on their V4 EZB, this connection method is the best I can come up with. Yes, jumpers like the ones sold in EZ Robot's store work OK but they seem loose and are easily mixed up and plugged into the wrong hole. If you have the room in your robot using headers and plugs keep your wires in the proper spot, make it much harder to attach them incorrectly and make a superior connection. In my couple years of experience building my B9 robot and over a decade of experience rebuilding and restoring solid state pinball machines I've found most electrical and electronic problems come from poor or mis-wired connections. ;)


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