@Egnos The Endpoints and Midpoints are the devices that boost the I2C signal because according to what I have read I2C by itself is distance limited.
You buy the Endpoints and Midpoints to give you the distance capability. I’m not advocating Endpoints and Midpoints because of the JST connectors.
Your original question was to the effect “I have this gesture sensor but I also have a distance requirement that I2C alone can’t handle” or words to that effect.
I suggested you look at the Sparkfun Endpoint and Midpoints because that is what their function is.
The best I have to offer is that I took a Raspberry Pi 4B, wired a Sparkfun Midpoint right next to the Pi. On a plastic panel, so the Midpoint was maybe 2 inches (50 mm) from Pi.
I plugged a 50 ft (15 meter) standard ethernet cable into that Midpoint.
I then took a Sparkfun ENDPOINT and plugged it into the far end of the ethernet cable. I connected 3 sensors to Endpoint.
As far as Seeed/Grove it says it is I2C on your link but I have no experience with the brand and connection other than I think the Grove connection, may be proprietary. That is inconsequential though as you can get the Qwiic sized JST and splice the connector.
When I first got the hardware I wanted to test the distance claim so slapped together the setup outlined above.
All I can say is that the Midpoint and Endpoint purpose is to give you the distance. I have attached a picture of my ad-hoc test. The Raspberry Pi + Midpoint are another 10 - 15 ft beyond the tail of the blue line. That blue line and white line are the 50’ of ethernet cable and red circle is Endpoint and 3 sensors which are all Adafruit I2C. I want to reiterate that my experience is with Adafruit and Sparkfun sensors and as a general rule those are the only brands I buy so can’t vouch for other brands. In the past I have bought sensors from other companies that advertise as I2C but are really SPI .
These companies will put their brand stamp on their connection by giving it a name such as “Qwiic Connector” or “Grove Connector” but they appear to be JST connectors except Grove may be proprietary.
The easiest way out is to buy this cable but it is dependent on you buying a Midpoint and an Endpoint from Sparkfun. I’m no expert but I know of no other way to push that I2C signal a longer distance.
If Grove is Seeed Studio’s proprietary connector you have to see if Seeed Studio has a solution for pushing I2C long distances and commit to using all Seeed Studio components. The other option is to get the parts I have provided links to.
Cable Length Edit.jpg