MN52H (nRF52840) Bluetooth Module Bi-directional Communication (MASTER/CENTRAL TO SLAVE/PERIPHERAL) Transmission Range Test

[TAIWAN, 15^th October. 2025]

Introduction

This report aims to thoroughly validate the maximum effective bi-directional communication range (MASTER/CENTRAL TO SLAVE/PERIPHERAL) of the Arad Technology MN52H BLE module in an open field environment, and to compare the influence of different antenna types (CHIP, PCB, u.FL) on transmission performance.

In Arad Technology’s previous transmission tests, we simulated a common Bluetooth data transfer scenario: communication between the MN52H module and an iPhone mobile phone. Although that test validated the product's performance in typical consumer applications, the iPhone’s transmit power (TX power) is significantly lower than the MN52H module's designed power capability. Consequently, the prior testing scenario did not allow us to measure the module's maximum potential transmission range.

Range Test iPhone to BLE Module

Given this limitation, the design objective for the current test is to simulate the industry-standard measurement scenario for wireless signal transmission range: bi-directional module-to-module communication between two high-power Bluetooth modules. This configuration is representative of advanced applications such as Bluetooth Mesh, Thread, and Matter. We are utilizing the MN52H-U40 as the MASTER/CENTRAL device to communicate with three MN52H modules featuring different antenna configurations. A wide-open beach area was chosen as the test location to minimize signal strength degradation caused by terrain obstruction. The ultimate goal is to determine the absolute communication performance limit of the MN52H module when operating at its full +8 dBm power output, thereby providing customers with the most accurate and valuable reference data on wireless transmission performance.

1. Test Objectives

• Validate the effective communication range of the MN52H BLE module's bi-directional communication (MASTER/CENTRAL TO SLAVE/PERIPHERAL) in an open field environment.
• Compare the communication performance of different antenna types (CHIP / PCB / u.FL).

2. Test Date

✅ October 2, 2025

✅ October 8, 2025

3. Test Environments

✅ Outdoor Environment: Open and unobstructed area.

4. Equipment Required

✅SLAVE/PERIPHERAL Device (Emitting Board):

l   Test Modules (MN52H-C40, MN52H-P40, MN52H-U40)

✅MASTER/CENTRAL Device:

l   Test Equipment (MN52H-U40)

✅Test Software: Arad Technology Test Firmware for Bluetooth Module.

✅Distance Measurement and Recording Tools: Google Maps, Mobile GPS Positioning.

5. Test Parameters

6. Test Procedure

This procedure aims to measure the maximum transmission range of the MN52H Bluetooth module under various antenna configurations in standardized and repeatable conditions.

6.1 Test Preparation and Connection Establishment

1. 1. Equipment Settings and Transmission Parameters:

l   Ensure both the SLAVE/PERIPHERAL devices (MN52H-C40, MN52H-P40, MN52H-U40) and the MASTER/CENTRAL device (MN52H-U40) have their TX Power set to +8 dBm.

l   Select the specified PHY mode (125K or 1M).

l   Transmission Rate Confirmation: Set the 125K mode to transmit 1 packet per second (PPS); set the 1M mode to transmit 4 packets per second (PPS).

2. Starting Point Positioning: Fix the SLAVE device at the starting point, with the antenna 3 meters above ground level, ensuring all antenna directions face the planned movement path.

3. Connection Confirmation: The MASTER device establishes an effective connection with the SLAVE device at the starting point and performs bi-directional packet transmission. The packet reception status will be displayed and confirmed by the flashing LED on the module.

6.2 Distance Measurement and Data Recording

1.   Incremental Testing: The MASTER device moves outwards along the Line-of-sight path in increments of 50 meters.

2.   Halt and Monitoring: At each measured distance point, confirm the connection status of the MASTER device and continue moving outwards.

l Connection Quality Confirmation: Judge the connection status by observing the flashing LED. A solid off or irregularly flashing LED indicates packet loss.

l Continuous packet transmission and reception is defined as an effective connection.

3.   Angle Influence Test: At the distance where the signal begins to attenuate, test the effect of different rotation angles of the SLAVE device antenna on the Packet Success Rate () to determine the signal radiation pattern and polarization effects of different antenna types.

4.   Maximum Range Determination: Continue moving until the connection cannot be stably maintained (e.g., continuously low Packet Success Rate or complete connection interruption, at which point the LED will stop flashing). Use Google Map and GPS positioning tools to accurately record the disconnection distance and the environmental characteristics at the point of disconnection.

7. Test Results Summary

1. 1. Comparison of maximum range under different transmission orientations.
   2. Performance comparison table for each antenna model.
   3. Test device version and firmware information.
   4. Record of test anomalies (e.g., packet loss).

**************************************Antenna Axis Defined**************************************

• 1M mode

• 125K long-range mode