The first couple of Proof of Concept(PoC) applications used a Seeedstudio SenseCAP RS485 500cm Ultrasonic Level Sensor (SKU 101991042). They also sell the SenseCAP RS485 750cm Ultrasonic Level Sensor which I found has exactly the same MODBUS interface setup.

Like the SenseCAP RS485 500cm Ultrasonic Level the SenseCAP RS485 750cm Ultrasonic Level Sensor has a Grove connector so the cable had to be “modified” before it would work with the RS485 Breakout Board for Seeed Studio XIAO (SKU 113991354).

The first step was to bend the crimp connector locks back using a very small screwdriver.

Then split the heat-shrink and cable outer, so the individual cables were longer.

The crimp connector at the of each wire had to be “modified” by trimming them with a pair of wire cutters (just in front of the crimped section) so that they could be inserted into the breakout board connectors.

The distance measurements were within a CM which was good. When I took the RS485 750cm Ultrasonic Level Sensor outside the distance returned was 0.0cm when the target was more 750cm away. I hadn’t noticed this with the Seeedstudio RS485 500cm Ultrasonic Level Sensor (SKU 101991042) as the ceiling in my office only 1.9M above the surface of my desk.