Missing "5-pin female header" on Hyperpixel

Hi All

I have a Hyperpixel 4.0 screen connected to a raspberry PI zero. I need to drive a relay. On this page


it says

You can use some jumper jerky to connect I2C devices to your HyperPixel 4.0, using the 5-pin female header on the underside of the board.

I can’t find any 5 pin header. Where is it? Am I being blind?

Am I correct in understanding that I need an additional bit of hardware to even drive a relay using one pin or can I just use pin BCM 10 directly to turn my relay on and off?

The original Hyperpixels had female Dupont connectors at the underside of the board (see this image), and later models moved to having the socket header instead for some reason.

I’m not sure how the socket header works, but I get the impression you’ll need an i2c relay to work with it.

The hyperpixel uses all of the GPIO pins and repurposes most of them.

To use i2c you have to use the secondary header on the back and
sudo ln -s /dev/i2c-3 /dev/i2c-1

Ohhhh… I see the header is the thing that looks like a big chip.
Has 2V3, SDA, SCL, INT and GND written next to it.

Yup, it’s very similar to this header but with slightly different metal pins, so you’d insert a piece of male jumper jerky vertically into the bottom of the screen if you were facing it.

Like I said I don’t know why they suddenly changed to the socket, the older pin header was compatible with Breakout Garden boards whereas the socket seems to be for the larger Adafruit Stemma connector (which is a pain, because Adafruit now mostly uses the smaller Stemma QT connector for i2c breakouts).

EDIT: Actually the pinout is all wrong for the Stemma connector, so I’ve no idea what it’s for!

Great, figured out how to plug stuff into it now!
So, if I only need to control one or 2 pins do I need extra hardware or can I just use pins BCM 10 and 11 as normal?

Looking around, the broken-out i2c bus seems to be some software magic, I’ve no idea how to control it as if it was a pair of digital pins. You could poke Pimoroni on Twitter and ask if that’s theoretically possible.

(Not sure if you saw the edit I made to my last post, that header seems physically compatible with Stemma connectors but is the wrong pinout, so don’t use those or else you might fry something).