M15 Setup and Troubleshooting – Rhombus Support

Topics included in this article:

Overview

The Rhombus M15 provides dependable motion detection to detect unauthorized access in privacy-sensitive zones. The M15 broadcasts to all nearby BLE-enabled Rhombus devices and allows users to stay in control through customizable alert schedules and real-time motion detection using the Rhombus console.

Screenshot 2024-10-25 at 2.31.32 PM.png

Compatible Devices

Before registering a Rhombus sensor, you will need a Rhombus device that supports the Rhombus Sensor Network. You can confirm by visiting the device specs web page on the Rhombus Systems corporate site and looking for the following icon:

Below is a list of compatible BLE gateway devices:

R120
R2
R170
R200
R230
R600
A100
DR40
E50

Setup and Registration

Battery Requirements

The M15 uses two (2) ER14505 Lithium batteries that should measure a nominal 3.6v.

Note: ER14505 batteries are exactly the same size and shape as traditional AA batteries, however, they have a different voltage. DO NOT install normal (1.5v) AA batteries into the M15; ensure that ER14505 batteries are used.

Battery Life

Expected Battery Life: Up to 5 years with typical medium-heavy use and correct battery type.

Battery Installation

1. Open the battery cover located on the back of the M15.

Screenshot 2024-10-25 at 2.33.46 PM.png

2. Insert the included 3.6V ER14505 batteries into the device and close the battery cover.

Registration

1. The M15 must be awakened from sleep mode to be registered. There are several ways to wake the device for registration:

Press the button on the M15.
Re-insert the battery into the M15.pulses green when waiting to be registered and stays

Note: The M15 LED pulses green when waiting to be registered and stays awake for 90 seconds before going back into sleep mode.

2. Once the green dot is pulsing, open the mobile app and navigate to "Register Devices" on the device page.

3. Select the M15(s) you want to register.

Note: You can confirm the correct device by comparing the serial number displayed on the app to the one on the back of the M15.

Bluetooth

Bluetooth is a wireless technology standard used for exchanging data between devices over short distances.

BLE Range

Under ideal circumstances, all Rhombus sensors can communicate via Bluetooth up to 300ft with a compatible Rhombus BLE enabled device.

BLE range can be affected by different factors, including but not limited to:

Obstacles: Physical obstacles such as walls, furniture, and other obstructions can weaken Bluetooth signals and reduce range.
Environmental Conditions: Environmental factors such as humidity, temperature, and electromagnetic interference can affect the device's performance.
Interference: Bluetooth operates in the 2.4 GHz frequency band, which is also used by many other wireless technologies, such as Wi-Fi, cordless phones, and microwaves. Interference from these devices can degrade Bluetooth signals and reduce range.

BLE Signal Strength

BLE signal strength is referenced as RSSI, Received Signal Strength Indicator. A higher RSSI value, like -10 (closer to 0), generally indicates a stronger signal, while a lower RSSI value, such as -85 (further from 0), indicates a weaker signal.

Signal strength can vary depending on factors such as distance, obstacles, interference, and the transmitting power of the Bluetooth devices involved. When evaluating BLE signal strength, it's important to consider these factors and ensure that the signal strength is sufficient for the intended application.

The signal strength in both the web and mobile app tells you how well the communication is between the sensor and paired Rhombus device.

Web Console	Mobile App

Located in the second column of the devices tab sensor view. (Hover over this icon to display the RSSI value).	Located on the right side of the list view.

Hardware Installation

The M15 sensor can be wall-mounted or mounted at an angle.

Mounting

1. Fix the mounting bracket to the desired flat surface using the 2 mounting screws provided (drywall anchors included if needed). Ensure that the arrow is pointing up. We recommend that the M15 be installed in direct line of sight with a BLE-enabled rhombus camera to reduce connectivity issues.
Optional Step: The included mounting adhesive can be used to attach the mounting bracket if screws are not desired.
2. Insert the M15 into the mounting bracket as shown.
3. Slide the M15 downwards across the mounting bracket until you hear a click.

Angled Mounting Bracket

The included angled mounting bracket is an optional accessory that expands M15’s capability to monitor motion events. Use the angled bracket to mount the M15 onto corners and flat walls, with an additional 30° downward-facing option to expand the M15’s detection FoV further.

Installing the angled mounting bracket requires two No. 6 rounded head screws (not included). Fix the angled bracket to the desired surface and secure the M15 in place.

Screenshot 2024-10-25 at 2.45.51 PM.png

Installation Best Practices

To reduce the likelihood of M15 failures, blind spots, and connectivity issues, the following points must be followed:

For best results, install roughly 2.4-3m (7.9 - 9.8ft) off the ground.
Have a BLE-enabled rhombus device in direct line of sight with the M15 to increase signal strength.
Avoid metal obstacles: This includes mounting the M15 behind a metal door, etc.
Ensure the M15 PIR Lens is unobscured and free from objects that could create false alarms.
Periodically test the M15 to ensure the desired response.
Regularly monitor M15 connectivity and signal strength to avoid sensor downtime.

Unregistering

You can unregister sensors from the phone app. You must be logged into the organization of the sensor(s) you want to unregister.

Please Note: To unregister the sensors, a BLE-compatible device must be connected to the network and within the sensor's range. Sensors must be unregistered before the Rhombus gateway device is unregistered.

1. Navigate to the Rhombus App "Devices" page.

2. Scroll to the bottom and click "Utilities."

3. Click on "Unregister Sensors."

4. Select the sensor(s) you want to unregister and complete the process.

Troubleshooting

Problem	Troubleshooting Steps
The mobile app crashes when attempting to register the sensor.	Update the mobile app or uninstall and reinstall it. Ensure no other devices are connected to BLE on the phone when attempting to register.
When registering a BLE sensor via the mobile app, the sensor is not present in the list of found sensors.	First, confirm the sensor is powered on and in the registration mode, typically indicated by a slow-blinking LED. If the sensor is powered and awaiting registration but doesn't appear in the list, close the mobile app entirely. This process may vary depending on the phone model. Once the app is closed, relaunch it and check if the sensor is now detected. If the issue persists, you may need to uninstall and reinstall the mobile app to ensure proper functionality.
The sensor’s reported battery life percentage in the console drops suddenly.	The reported battery life of a sensor may dip significantly for a short amount of time immediately post-bootup (when the batteries are installed). This is normal, and the reported battery life should return to normal within an hour or two.
The motion sensor does not accurately report occupancy within a room.	The motion sensor range is ~5m with a 90-degree field of view. If the room is larger than this or the sensor is positioned so that it misses some of the room, it may reduce the reporting accuracy.
The motion sensor initially detects room occupancy but reports that it is vacant before the occupant leaves.	Ensure the sensor is placed strategically to cover the entire room. Movement may be detected when someone enters, but then they move into an unmonitored area. Also, note that a person sitting still might not trigger the motion sensor.

Helpful Links

Assigning Alert Policies

Contact Support or Sales

Have more questions? Contact Rhombus Support at +1 (877) 746-6797 option 2 or support@rhombus.com.

Interested in learning more? Contact Rhombus Sales at +1 (877) 746-6797 option 1 or sales@rhombus.com.