Mobile equipment control box via bluetooth BLE

TECHNICAL SPECIFICATION Bluetooth Low Energy (BLE) Electronic Control Module with 6 Relay Outputs Document Version: 1.0 Prepared By: Stéphane Gagnon Date: August 13, 2026 ________________________________________ 1. Purpose This document defines the technical requirements for the design, manufacture, and delivery of an electronic control module capable of controlling six (6) independent relay outputs through Bluetooth Low Energy (BLE) communication. The system shall be designed for industrial, mobile, and outdoor applications and shall operate from either a 12 VDC or 24 VDC power source. ________________________________________ 2. General Description The control module shall include: • A Bluetooth Low Energy (BLE) compatible microcontroller. • Six (6) independently controlled relay outputs. • Supply voltage monitoring and reporting. • Two (2) status indicator LEDs. • Sealed Deutsch connectors for all external connections. • An enclosure with a minimum protection rating of IP67. • Mounting provisions allowing installation using either two (2) or four (4) bolts. • Embedded software with complete editable source code supplied to the customer. ________________________________________ 3. Power Supply Requirements Parameter Requirement Nominal Supply Voltage 12 VDC or 24 VDC Operating Voltage Range 10 VDC to 30 VDC Power Type DC Power Reverse Polarity Protection Required Overvoltage Protection Required Short Circuit Protection Recommended The device shall automatically operate on either 12 VDC or 24 VDC without requiring configuration changes. ________________________________________ 4. Bluetooth Communication Communication Technology Parameter Requirement Wireless Technology Bluetooth Low Energy (BLE) Minimum Version BLE 5.0 Minimum Range 10 m (33 ft) Simultaneous Connections Minimum 1 Security Secure pairing and authentication Required BLE Functions The control module shall support: • Individual relay activation. • Individual relay deactivation. • Reading the status of each relay. • Command acknowledgement. • Reading the module supply voltage. • Transmitting the supply voltage to a connected BLE device. • Reading the overall controller status. ________________________________________ 5. Supply Voltage Monitoring The controller shall continuously monitor its input supply voltage and make the value available through BLE communication. Parameter Requirement Measurement Range 10 VDC to 30 VDC Resolution Minimum 0.1 V Target Accuracy ±2% Measurement Unit Volts (V) Communication Method BLE Maximum Update Interval 1 second The microcontroller shall use an integrated ADC or a dedicated voltage monitoring circuit for measurement purposes. ________________________________________ 6. Relay Outputs Quantity • Six (6) independent relays. Minimum Requirements Parameter Requirement Number of Relays 6 Control Method Independent Minimum Switching Capacity 20 W per relay Switching Time ≤ 20 ms Galvanic Isolation Recommended Each relay shall be independently controllable through BLE commands. ________________________________________ 7. Environmental Requirements Parameter Requirement Minimum Operating Temperature -40°C Maximum Operating Temperature +50°C Storage Temperature -40°C to +70°C Relative Humidity 10% to 90%, non-condensing Minimum Ingress Protection Rating IP67 All components, including the microcontroller, relays, LEDs, connectors, and passive components, shall be rated for reliable operation within these environmental conditions. ________________________________________ 8. Status Indicators The module shall include two externally visible LEDs. Power LED Recommended Color Function Green Indicates that power is applied The LED shall remain continuously illuminated whenever power is present. Bluetooth Activity LED Recommended Color Function Blue Indicates BLE communication activity The LED shall flash whenever data is transmitted or received via BLE. ________________________________________ 9. Microcontroller Requirements The microcontroller shall perform the following functions: • BLE communication management. • Control of the six relay outputs. • Management of status LEDs. • Supply voltage measurement. • Transmission of monitored data via BLE. • Automatic recovery after power loss. • Optional restoration of the relay states after power-up. Examples of suitable platforms include: • Nordic nRF52840 • ESP32-C3 • ESP32-S3 • Equivalent BLE-capable microcontrollers ________________________________________ 10. Mechanical Enclosure Construction The enclosure shall be manufactured from industrial-grade materials such as: • Polycarbonate • Industrial ABS • Equivalent material Environmental Protection The assembled enclosure shall meet a minimum ingress protection rating of IP67. The enclosure shall: • Be dust-tight. • Withstand temporary immersion in water. • Maintain its protection rating when all connectors are properly installed and locked. Mounting Requirements The enclosure shall include four (4) integrated mounting points allowing: • Installation using two (2) bolts. • Installation using four (4) bolts. Parameter Requirement Total Mounting Points 4 Minimum Installation Configuration 2 bolts Maximum Installation Configuration 4 bolts ________________________________________ 11. Connectors Connector Type All external electrical connections shall use sealed industrial-grade Deutsch DT series connectors or approved equivalents. Parameter Requirement Connector Type Deutsch DT Series or equivalent Minimum Protection Rating IP67 Locking Mechanism Positive mechanical lock Vibration Resistance Industrial grade Operating Temperature -40°C to +50°C Power Connector The power connector shall include at minimum: • 1 × Positive Supply (+12/24 VDC) • 1 × Ground (GND) Relay Connections The six relay outputs shall be available through one or more sealed Deutsch connectors. All connections shall be permanently identified and labeled. ________________________________________ 12. Reliability Requirements The system shall: • Withstand vibration levels typical of industrial and mobile equipment applications. • Automatically restart following power interruptions. • Maintain or restore the previous relay state after power recovery (configurable option). • Operate reliably throughout the specified environmental range. ________________________________________ 13. Embedded Software and Intellectual Property Source Code Delivery The supplier shall provide the complete editable source code for the firmware running on the microcontroller. The delivered software package shall include: • Complete source code. • Project files. • Configuration files. • Libraries used by the project or references to obtain them. • Build scripts, if applicable. • Programming and flashing procedures. ________________________________________ Software Modifiability The firmware shall be delivered in a fully editable format. No hardware or software restrictions shall prevent: • Source code access. • Software modification. • Firmware recompilation. • Reprogramming of the microcontroller. • Future product enhancements. ________________________________________ Software Documentation The supplier shall provide, at minimum: • Firmware architecture description. • BLE services and characteristics documentation. • Relay control command descriptions. • Description of all transmitted data, including supply voltage reporting. • Firmware update procedure. ________________________________________ Intellectual Property Upon project delivery: • The customer shall receive full access to the firmware source code. • The customer shall have the right to modify the firmware. • The customer shall have the right to reproduce and evolve the firmware for internal use. • No technical restrictions shall prevent maintenance or future development of the product. ________________________________________ 14. Acceptance Criteria The product shall be considered compliant when the following conditions are met: 1. All six relays respond correctly to BLE commands. 2. Each relay supports a minimum switching load of 20 W. 3. The system operates correctly from both 12 VDC and 24 VDC power sources. 4. Supply voltage is measured and transmitted over BLE. 5. Voltage resolution is at least 0.1 V. 6. The power LED functions correctly. 7. The BLE activity LED functions correctly. 8. Reliable operation is demonstrated between -40°C and +50°C. 9. All external connections utilize sealed Deutsch connectors. 10. The enclosure meets a minimum IP67 protection rating. 11. The enclosure can be mounted using either 2 or 4 bolts. 12. Complete firmware source code is provided. 13. Firmware project files are provided and can be successfully rebuilt. 14. The microcontroller can be reprogrammed by the customer. 15. Firmware and BLE interface documentation are supplied. ________________________________________ Summary of Key Requirements ✅ Bluetooth Low Energy (BLE 5.0 minimum) ✅ Six (6) independently controlled relays ✅ Minimum relay load capacity of 20 W per relay ✅ 12 VDC and 24 VDC operation ✅ Supply voltage monitoring and BLE reporting ✅ Power status LED ✅ Bluetooth activity LED ✅ Sealed Deutsch DT connectors ✅ Minimum IP67 enclosure rating ✅ Operating temperature range: -40°C to +50°C ✅ Mounting using either 2 or 4 bolts ✅ Complete editable firmware source code included ✅ Firmware documentation and BLE protocol documentation included ✅ Designed for industrial, mobile, and outdoor applications.