Expansion Board with 2 SSRs

Hi there,

I just acquired a TRUE GDM-6 and am in the initial stages of planning a BrewPi build (the newest version is arriving today!)

My goal is to make the exterior of the TRUE as clean looking as possible. Hence I came across the SSR Expansion board.

According to the product description it seems like I could have only a single OneWire coming out of my BrewPi and going into the fridge, thus hiding the extra SSR wires etc.

A have a few questions however.

  1. If I want to control 2 SSRs (one for heating, one for cooling) do I need to have 2 expansion boards? This 2 OneWires coming out of the BrewPi?

  2. In the product description it says you need to use a “gray connector” to connect two SSRs. What product is that in the store?

I think that’s it (for now). I’ll be updating my progress in the fridge build board for all to see as I run through this.


@Moortown, I have 3 sparks and 3 expansion boards setup similar to the way you want to.

answers to your questions.

1: No you only need one to control 2 SSR’s, they have an A and B channel. SO only one wire from Spark.

2: The grey connectors are on the expansion board. See picture below, you can connect one SSR to Channel A, using either the tabs on the end or the grey ‘A’ channel connector ( Both Circled Blue ), and then connect the second SSR to channel ‘B’ using grey connector for channel ‘B’ ( Circled Red).

And as you can see here you end up with 2 devices with the same OneWire address but with an ‘Output A’ and ‘Output B’.


Thanks Rich!

One more question: did you find that you needed to use the Brewpi store’s version of the RJ12 cable to go to the expansion board? In the product description it is recommended.

I’m just being picky in that I’d like it to be a black wire which I could make it if any RJ12 cable would work.

Again thanks for the help!

I think any RJ12 should work but they’re generally lower quality cables so can only do short runs. The ones on the store are actually CAT5e cable with RJ12 connectors. You can make your own cables up pretty easy if you buy an RJ12 terminating tool. They’re pretty cheep on ebay.

I agree, I made my own cables, work in IT networking so already had the crimpers etc…

Great idea. I think I actually have one of those tools hanging around.

Ordering my expansion board tonight!

Look for my build post to begin soon!

I apologize a head of time if this is in the wrong category. What solution / how do you appropriately wire the Spark v3 to

in order for it to control multiple relays. I.e there are only 5x actuators but I have 12x devices I want to control.

@Elco how or will the new software support this? or is there a hardware solution I am missing? please advise.

thank you!

That’s what our ssr expansion boards are for. Each will give you 2 extra outputs and an extra place to plug in some sensors.

To control all of them with the software, you’ll need our new BrewBlox platform, but a beta release is close.

For controlling DC devices up to 24V, I have a new board in production, also giving you 2 extra output switches.

ok so for me since I have a total of 12 devices that I want powered through the SSR relay board, and the Spark v3 has 5 I would need 4x boards?
I assume the wiring for them is the same as:

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Yes, pinout is the same as on the spark. We have premade cables at different lengths in the store too.

@Moortown & @rbpalmer - I wanted to clarify the SSR boards. Based on what I have read it sounds like the boards support two relays ea. or max. and in order for the Brewpi to talk to the expansion boards there has to be a 1 wire cable (phone cable with pin out as seen below). Can you daisy chain the expansion boards like you can the control boards for the ball valves + 2 temperature sensors? Or like I have seen in the pictures you can have 1-wire cable with 2x SSRs and daisy chain using the grey connector (red). So in my case I have 4x boards, I would need 2x 1 wire cables and have the SSRs connected using the grey connector,

Input, thoughts etc. greatly appreciated. See my comments below if you need further reference.

Yes, you can daisy chain the rj12 ports.
As @rbpalmer showed, one of the grey outputs is also connected to the slots to mount to an SSR, so the easiest setup is to screw to one ssr and connect the second one to the grey B terminal.

I just wanted to add that I finally figured out (lots of life events, since time has passed) that the Pos + on the expansion boards go to the IN-x on my SSR 8x & 4x boards. And the Negative - goes to the 2nd Ground GND on my type of SSR Board. Finally got this figured out and beginning testing all my connections again.

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