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Need More 3-Pin E-Block Connections


The Cobra has 6 3-Pin E-Block connectors built-in. But one Motor Driver will take up all 6, and then there is the servo controller, and the sensors that are needed. So how can you get more E-Block connectors hooked up to the Cobra board (I bought a Component Shield but am now told it is not compatible with the Cobra board)?


Can you do simple soldering? Then you can use the proto board and solder all the JST connector you like


Thanks for the reply. I can give that a shot. But then looking at the code, for instance for the Motor Driver, an E-Block on the board is referrenced as a single FEZ Pin – e.g. (FEZ_Pin.PWM.Di9), but it will be three pins on the protoboard – How does one reference each E-Block once soldered to the Proto Board? Also, not sure what is the difference between using the Proto Board and the IO40 board… Can you also solder E-Blocks to the IO40 board? Thanks.


I am not sure what you mean.
The 3-pin connectors are Ground, signal and V+
Signal is connected to a FEZ pin, Ground and V+ is connected to a power supply. (either the one from cobra or build your own)


Look at the pin names and try them in code, they should work. Do not worry about if the name starts with Di or IO, the names are different for internal reasons but they function the same


Is there info anywhere on how to use the Proto board or the IO40 board? Never done this before (I am a programmer, new to electronics). What do you use to make connections across the proto board? How do you use the IO40 board with 3-pin E-Blocks? Do you need to wire it to a protoboard the same way? Are there basic instructions somewhere?


Can you do basic soldering?


Soldering is not a problem. But is there info on how to connect the proto board to the Cobra board? Is there info on what each of the connections does, or how it should be used? Is there any guidance on how to attach an E-Block to any of these boards since obviously the pin spacing doesn’t match?


I have seen this requested before so let me writeup some guide for this to help you and others. Note that we are busy with EW in Germany the whole week so this will be done after.

The pinout of the connector is here if you want to try to figure out. It shouldn’t be very difficult


So here’s what I would do if I were you.

I’d consider cutting cables and connecting things myself. JST connectors are mainly for convenience (always have power and GND and signal at each point; polarised connection so you can’t screw it up) but are far from the only solution here.

I guess you now realise this. The chances are that anything called a “shield” is meant to fit on the Domino and Panda line, that have a small number of pins laid out in an “arduino compatible” configuration. That is a convenience factor to allow the Domino and Panda to use those shields not specifically designed for the netmf boards - thus increasing the range of peripherals possible to connect with little thought.

Your Cobra has a row of holes that are your pin-outs. Use them to mount either a set of male or female pins. Then I’d consider making my own “protoboard” from stripboard or veroboard that I can then mount the opposite pins to, and plug the two together when I want. Of course, you could always buy the Cobra prototype board,, and that has everything you need :slight_smile: Then all you have to do is solder your wires into the pads you want, joining the points to the relevant pin-out location


I don’t have a cobra proto, so may be wrong here. Moreover, not sure from looking at why it looks like groups of two via pairs. I assume a pair is connected with a trace?

If so, the picture below may help you.

  1. Insert a JST with center pin on signal pin you want.
  2. Jumper a GND wire from gnd bus to left side of jst notch.
  3. Jumper a 3.3v wire from a 3.3v bus to right side JST.

If your interested, I could do a jst PCB and post it that would make this a bit easier for using jst blocks. Then just send to pcb house. I think maybe do like 10 pins or something so it is more managable size. Could then just add more boards if you needed more then 10 jsts.


Not sure how much time or money a custom pcb would be, although it sounds like something GHI should already have… How about if I wire the Component Shield (intended for Domino and Panda) to the Cobra Proto board?


GHI already provides the prototyping board

and the connectors

and the cables

The component shield should only be used with Domino/Panda


Thanks Gus - I have the proto board, the connectors, and the cables all sitting here in front of me. But the JST 3 pin Connectors cannot be mounted on the Proto board, so they need to be mounted on another board - which can be custom made as William suggests. But isn’t that all the Component Shield is? JST connectors mounted on a board?


Like I promised earlier, there will be a writeup explaining how to do it


"Not sure how much time or money a custom pcb would be, although it sounds like something GHI should already have… "

A 10 pin version would be around $5 (plus headers) (20 pin would be $10, etc). The thing I like about it is using std female pin headers on the cobra instead of locking into the 90deg ones. With the headers, you can use jst board, raw jumpers, or the proto and switch them out. You could do it with component shield, but how? Solder a bunch of wires under it? Big mess I think and it will not lay down. The only way to realistically do it is a pcb. Hey, it is all part of the fun.


Thanks Gus,

Any idea when you’ll have this written up?


Just got back from Germany…so very shortly


I started new thread for this


I soldered the connectors onto the proto board per Gus’s instructions. But when I test each one, just trying to light an LED, I get a hardware error “An unhandled exception of type ‘System.Exception’ occurred in Microsoft.SPOT.Hardware.dll” on the following line in the LED driver: “led = new OutputPort((Cpu.Pin)pin, true)”. Must be something else I need to do to make this work… Sorry, not sure what it is I need to do to get the pins to work. Thanks.