I've purchased some scales for use with a mini milling machine and the open source DRO-550 digital readout platform. They are essentially equivalent to permamenet mount digital vernier calipers so that the X/Y/Z position of the milling table can be tracked and displayed. The end product is shown below with the included LCD readout:

DRO scales

Many scales use a standard mini USB connector even though the protocol is more SPI-like, however these use a 4-pin connector that I'd like help identifying. In the first photo the top scale of the ruler is 1/64" so it appears pin spacing is either 1/32" or 0.8mm, which I've also confirmed by measurement to reduce parallax.

DRO connector 1

The following photo taken on a different angle shows there are two rows of pins although they are physically connected so it is a 4-pin connector. The overall outer dimensions of the protrusion that pushes into the socket is around 0.2" / 5.2mm wide by 0.12" / 3mm high, so a little smaller than a mini USB.

enter image description here

I'd prefer not to cut the cables and re-terminate so wondered if this is a standard connector type that anyone can identify?


1 Answer 1


I managed to identify the connector after exhaustive searching of various suppliers through all 0.8mm pitch connectors. It is a member of the Hirose MQ172X Series with the 4-pin SMT receptacle being a Hirose part number MQ172X-4PA. After locating the part number it is widely available from Element 14, Digikey, Mouser etc.

Rather than make a custom PCB for a one-off I've ordered a couple of DFN-8 to DIP-12 SMT adapters from Proto Advantage (part number IPC0065) that I'll cut in half to mount the connectors to.


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