Using computer technology, sensor technology, and wireless communication, this paper presents the design of a wireless sensor network for monitoring PCB board electroplating current. The system utilizes the NRF9E5 microcontroller as the wireless sensor node, incorporating a Hall current sensor and detection circuit to enable wireless communication between the sensor node and the computer. The primary function of a PCB board is to connect various electronic components in a predetermined circuit, and its quality directly impacts the performance of the entire electromechanical product. PCB electroplating current is a crucial factor influencing the quality of PCB boards. Currently, PCB electroplating current detection is carried out manually by operators using handheld monitoring devices at set intervals. However, this method has several drawbacks, such as lack of real-time detection, potential for missed or false readings, and health risks from prolonged exposure to the electroplating environment. Given that manual detection is no longer adequate for meeting the demands of modern manufacturing, this paper proposes a wireless transmission solution for monitoring PCB electroplating current. In this approach, sensor nodes are placed at key points to detect the electroplating current, with a central monitoring system providing real-time data collection and control.
1. **System Framework**
The structure of the PCB electroplating current monitoring system based on a wireless sensor network can be divided into three layers: the data acquisition layer, the system communication layer, and the management layer. In this framework, the data acquisition layer forms the core of the system, consisting of sensor nodes and sink nodes placed within the working environment. Through the integrated data acquisition unit, the sensor node collects the current signal flowing through the PCB board, processes the data, and then transmits it wirelessly to the sink node. The sink node aggregates, analyzes, and stores the data received from the sensor node, while awaiting commands from the computer, with the capability to communicate with the computer. The system communication layer refers to the communication between the sink node and the computer, using RS232 serial communication. By configuring P0_ALT.1=1 and P0_DIR.1=1, the second function of the P01 and P02 pins of the NRF9E5 is selected as the RXD and TXD for serial communication. The MAX232 chip performs level conversion, enabling connection to the computer’s serial port for processing the data collected from each node and sending control instructions and valid data to configure each node and control the field equipment. The management layer is responsible for the computer analyzing and processing the collected electroplating current data. The computer collects the current data from the installed Hall sensor nodes as required by the administrator and performs various management tasks, including data processing, chart display, control, and storage. If the current flowing through the PCB board exceeds or falls below the predefined threshold, the system triggers an audible and visual alarm.
2. **System Hardware and Design**
The wireless sensor node is the fundamental unit of the entire wireless network. Its main task is to collect PCB electroplating current data, pre-process it, respond to commands from the host computer, and then send the collected data to the host computer. The wireless sensor node consists of the NRF9E5 microcontroller, a wireless communication unit, a sensor unit, and an indicator light alarm circuit.
2.1 **Wireless Communication Unit**
The NRF9E5 wireless microcontroller integrates a 433MHz, 868MHz, or 915MHz transceiver (NRF905), making the system design simpler and more reliable. Through software programming, the transceiver can automatically handle functions such as transmission, reception, and monitoring. From a system design perspective, the software is responsible for interpreting and controlling the data within the data packet.
2.2 **Sensor Unit**
The sensor unit is primarily responsible for collecting current information, which is crucial for the overall system performance. First, the current signal is converted into a voltage signal. In this design, the TBC-LTA series Hall current sensor is used. It operates with a power supply voltage of ±(12~15)V and a working temperature range of -40~85°C. To improve measurement accuracy, the TDC503LTA sensor from the TBC-LTA series of DC current sensors is selected, based on the actual current values to be measured. The NRF9E5 microcontroller features a 10-bit linear ADC with a conversion rate of 80kS/s. The reference voltage for the ADC can be selected via software, either as the Aref input or the internal 1.22V bandgap reference voltage. The ADC has five selectable inputs and typically operates in start/stop mode, with the sampling time controlled by software. By default, it is 10-bit, but the resolution can be adjusted to 6-bit, 8-bit, or 12-bit via software. Additionally, the ADC can operate in differential mode, where AIN0 is used as the negative input and AIN1-3 serve as the positive inputs.
2.3 **Indicator Light Alarm Circuit**
When the current flowing through the PCB board falls below the lower limit or exceeds the upper limit, the indicator light alarm circuit generates both audible and visual signals to alert the manager, enabling immediate corrective action. In this design, the alarm circuit consists of a red LED and a speaker.
3. **System Software Design**
3.1 **Lower Computer Software Design**
In modern wireless communication, data is transmitted in packets. For wireless SoCs like the NRF9E5, data is sent and received in the form of packets. The packet format is an essential part of the communication protocol. The data packet format of the NRF9E5 consists of: Preamble, ADDR, PAYLOAD, and CRC. The Preamble is automatically added by the hardware, ADDR sends a 32-40-bit address code, PAYLOAD contains the valid 32-bit data, and CRC is the cyclic redundancy check for error detection, which is automatically generated by the hardware and can be set to 0, 8, or 16 bits. The key task of the sensor node is to transmit the collected data. To enable wireless transmission, the wireless transceiver in the processor must operate in transmit mode. The NRF905 transceiver supports three operating modes: ShockBurst receive (RX) mode, ShockBurst transmit (TX) mode, and energy-saving mode.
3.2 **PC Software Design**
The host computer software is programmed using Visual C++ and includes a real-time current display panel and a database for storing data. After the wireless sensor network is deployed, the data from multiple sensor nodes is transmitted to the computer, where the host program stores the data, making it easier to query and process in the future. Visual C++ offers three database access methods: ODBC, DAO, and OLEDB. ODBC provides an application programming interface (API), allowing any database to be managed through these APIs. The general procedure for using an ODBC database in the MFCAppWizard is as follows: 1) Create a database using database tools like Access; 2) Define an ODBC data source for the database created in step 1; 3) Select the defined data source in the application wizard; 4) Design the interface and link the controls to the corresponding database fields. In this design, a database is created with several data tables based on the number of sensor nodes, and the ODBC classes provided by MFC (such as the recordset class, database class, and visual recordset class) are used for programming. Data uploaded by each wireless sensor node is stored in separate data tables according to the node’s identification number.
4. **Conclusion**
This system’s wireless sensor node is based on the low-power NRF9E5 microcontroller, utilizes TBC-LTA series Hall current sensors, and integrates computer and wireless sensor network technologies to perform real-time data acquisition and A/D conversion for PCB electroplating current. The collected current data is analyzed and stored, providing an effective solution for monitoring PCB electroplating current production, improving PCB quality, and enhancing product competitiveness. The system is characterized by low cost, low power consumption, high detection accuracy, ease of use, and user-friendly design. It addresses the challenges of monitoring PCB electroplating current effectively and shows promising prospects for further application and development.
If your have any questions about PCB ,please contact me info@wellcircuits.com
1. **System Framework**
The structure of the PCB electroplating current monitoring system based on a wireless sensor network can be divided into three layers: the data acquisition layer, the system communication layer, and the management layer. In this framework, the data acquisition layer forms the core of the system, consisting of sensor nodes and sink nodes placed within the working environment. Through the integrated data acquisition unit, the sensor node collects the current signal flowing through the PCB board, processes the data, and then transmits it wirelessly to the sink node. The sink node aggregates, analyzes, and stores the data received from the sensor node, while awaiting commands from the computer, with the capability to communicate with the computer. The system communication layer refers to the communication between the sink node and the computer, using RS232 serial communication. By configuring P0_ALT.1=1 and P0_DIR.1=1, the second function of the P01 and P02 pins of the NRF9E5 is selected as the RXD and TXD for serial communication. The MAX232 chip performs level conversion, enabling connection to the computer’s serial port for processing the data collected from each node and sending control instructions and valid data to configure each node and control the field equipment. The management layer is responsible for the computer analyzing and processing the collected electroplating current data. The computer collects the current data from the installed Hall sensor nodes as required by the administrator and performs various management tasks, including data processing, chart display, control, and storage. If the current flowing through the PCB board exceeds or falls below the predefined threshold, the system triggers an audible and visual alarm.
2. **System Hardware and Design**
The wireless sensor node is the fundamental unit of the entire wireless network. Its main task is to collect PCB electroplating current data, pre-process it, respond to commands from the host computer, and then send the collected data to the host computer. The wireless sensor node consists of the NRF9E5 microcontroller, a wireless communication unit, a sensor unit, and an indicator light alarm circuit.
2.1 **Wireless Communication Unit**
The NRF9E5 wireless microcontroller integrates a 433MHz, 868MHz, or 915MHz transceiver (NRF905), making the system design simpler and more reliable. Through software programming, the transceiver can automatically handle functions such as transmission, reception, and monitoring. From a system design perspective, the software is responsible for interpreting and controlling the data within the data packet.
2.2 **Sensor Unit**
The sensor unit is primarily responsible for collecting current information, which is crucial for the overall system performance. First, the current signal is converted into a voltage signal. In this design, the TBC-LTA series Hall current sensor is used. It operates with a power supply voltage of ±(12~15)V and a working temperature range of -40~85°C. To improve measurement accuracy, the TDC503LTA sensor from the TBC-LTA series of DC current sensors is selected, based on the actual current values to be measured. The NRF9E5 microcontroller features a 10-bit linear ADC with a conversion rate of 80kS/s. The reference voltage for the ADC can be selected via software, either as the Aref input or the internal 1.22V bandgap reference voltage. The ADC has five selectable inputs and typically operates in start/stop mode, with the sampling time controlled by software. By default, it is 10-bit, but the resolution can be adjusted to 6-bit, 8-bit, or 12-bit via software. Additionally, the ADC can operate in differential mode, where AIN0 is used as the negative input and AIN1-3 serve as the positive inputs.
2.3 **Indicator Light Alarm Circuit**
When the current flowing through the PCB board falls below the lower limit or exceeds the upper limit, the indicator light alarm circuit generates both audible and visual signals to alert the manager, enabling immediate corrective action. In this design, the alarm circuit consists of a red LED and a speaker.
3. **System Software Design**
3.1 **Lower Computer Software Design**
In modern wireless communication, data is transmitted in packets. For wireless SoCs like the NRF9E5, data is sent and received in the form of packets. The packet format is an essential part of the communication protocol. The data packet format of the NRF9E5 consists of: Preamble, ADDR, PAYLOAD, and CRC. The Preamble is automatically added by the hardware, ADDR sends a 32-40-bit address code, PAYLOAD contains the valid 32-bit data, and CRC is the cyclic redundancy check for error detection, which is automatically generated by the hardware and can be set to 0, 8, or 16 bits. The key task of the sensor node is to transmit the collected data. To enable wireless transmission, the wireless transceiver in the processor must operate in transmit mode. The NRF905 transceiver supports three operating modes: ShockBurst receive (RX) mode, ShockBurst transmit (TX) mode, and energy-saving mode.
3.2 **PC Software Design**
The host computer software is programmed using Visual C++ and includes a real-time current display panel and a database for storing data. After the wireless sensor network is deployed, the data from multiple sensor nodes is transmitted to the computer, where the host program stores the data, making it easier to query and process in the future. Visual C++ offers three database access methods: ODBC, DAO, and OLEDB. ODBC provides an application programming interface (API), allowing any database to be managed through these APIs. The general procedure for using an ODBC database in the MFCAppWizard is as follows: 1) Create a database using database tools like Access; 2) Define an ODBC data source for the database created in step 1; 3) Select the defined data source in the application wizard; 4) Design the interface and link the controls to the corresponding database fields. In this design, a database is created with several data tables based on the number of sensor nodes, and the ODBC classes provided by MFC (such as the recordset class, database class, and visual recordset class) are used for programming. Data uploaded by each wireless sensor node is stored in separate data tables according to the node’s identification number.
4. **Conclusion**
This system’s wireless sensor node is based on the low-power NRF9E5 microcontroller, utilizes TBC-LTA series Hall current sensors, and integrates computer and wireless sensor network technologies to perform real-time data acquisition and A/D conversion for PCB electroplating current. The collected current data is analyzed and stored, providing an effective solution for monitoring PCB electroplating current production, improving PCB quality, and enhancing product competitiveness. The system is characterized by low cost, low power consumption, high detection accuracy, ease of use, and user-friendly design. It addresses the challenges of monitoring PCB electroplating current effectively and shows promising prospects for further application and development.
If your have any questions about PCB ,please contact me info@wellcircuits.com
