What is the needed size of the JST 2-pin connector on the Grow?

I recently bought the Pimoroni Grow and was looking to hook up a 5V pump to three male 2-pin JST connectors on the bottom.

Can anybody confirm what is the needed JST connectors?

For example these ones have a female body width of 3mm while others I’ve seen can have body widths of 4.6mm.

I don’t have a Grow, but looking at this product photo:

and comparing the spacing of the connector traces with the size of the HAT mounting holes (2.5mm), those are three-pin 1.25mm JST. Getting 2-pin JSTs to fit would be a trick and a half. :grin:

Hi! You’ve got sharp eyes.

Actually, the 2-pin connectors are on the back side of the device. It’s impossible to see on the pictures from the website but you can just make it out on the tutorial page:

Ah. Just took another look at the Grow product page, and down in the specs section:

  • 3 x Picoblade 2P-compatible connectors with MOSFETs for turning low current 5v devices on and off.

From what I understand, PicoBlade and JST-1.25 connectors are easily confused, and I haven’t come across anything that says one can be jammed into the other (I’ve only used JST-1.25 so far), so you’d probably want to:

  1. wait for your Grow to be delivered,
  2. compare the 2-pin connectors’ pin spacing with the Grow sensor cable’s plug, to verify the pin pitch, then
  3. order Picoblade-specific connectors in the correct pitch (avoid any seller that breathes “JST” and “PicoBlade” in same product listing)

It seems there’s an upcoming part 2 to the Grow tutorial that gets into those other connectors, so if you can wait, that might be the safest option.

Hi @lexfiend

It’s not so easy to measure these things so I think I would have to trust the specifications on that ad and assume that the connectors are 1.25mm pitch picoblade connects. The annoying thing is that I can’t seem to find any standard source of these pre-cruimped on ebay or amazon.

I think this is what I’m looking for: https://www.adafruit.com/product/4720

I’ve searched for “Pico 1.25mm” but not much pops up and as you note, it seems dominated by JST 1.25mm listings.

Really quite annoying as I’m looking to just attach pumps to this grow as a Christmas present and it seems difficult to find a supplier of this simple connector in the UK.

I’ve taken some more clear pictures of the mystery connectors (top):

And another picture (since I’m unable to put more than one picture per post)

I think what I’m looking for is the Molex 15134-002 picoblade female connector. I’d appreciate it if anybody could confirm:


Pretty darn expensive to get 3x and with shipping. It’ll cost almost half of what was paid for the Grove.

The moisture stick connectors are jst sh (1mm pitch), the pump connectors are molex picoblade 1.25mm, which is different from JST’s 1.25mm offerings.