Project Number: P13037 NTID NOTIFICATION ALERT SYSTEM PHASE IV. Jared Lytle Electrical Engineering

Transcription

1 Multidisciplinary Senior Design Conference Kate Gleason College of Engineering Rochester Institute of Technology Rochester, New York Project Number: P13037 NTID NOTIFICATION ALERT SYSTEM PHASE IV Mark Calem Electrical Engineering Abstract Jared Lytle Electrical Engineering Muhammad Ibrahim Electrical Engineering NTID Notification Alert System was designed mainly for deaf/hard hearing people. The device was designed to alert hard-hearing people on coming text, , emergency alert, and alarm clock. The device was designed to work with any android device using physical connection and also Bluetooth connection. The alert systems designed for the device were using high intensity LED and bed shaker. These two crucial alert systems made the device as an effective device for alerting hard hearing people. This was parallel with the project objective which was to give effective alert system and to make life easier for deaf/hard hearing people to set their alarm by having a Bluetooth connection from the device to their android devices. Nomenclature NAS- Notification Alert System NTID- National Technical Institute for the Deaf MSP Bit Risc Microcontroller LaunchPad- MSP430 Development board Bed Shaker Device that is placed under the mattress to awaken users. LED- Light Emitting diode BlueGiga WT12- Bluetooth communication module with antenna PCB- Printed Circuit Board UART- Universal Asynchronous Receiver and Transmitter Copyright 2013 Rochester Institute of Technology

2 Introduction The objective of the project was to design an effective alert system for deaf/hard hearing people by using high intensity LED and bed shaker. This project was a continuation from a previous Senior Design Team group, P However, this project focused on the use of brighter LEDs and aimed at reducing cost by utilizing the MSP430 over an ARM microcontroller. The stand was designed with a tablet stand so that the stand could be used as an alarm clock but also as a SKYPE station Originally, the project was also required to have Bluetooth connection with both Android and IOS devices. However, due to some requirement from Apple to establish Bluetooth connection from the device to the IOS phone/tablet the requirement cannot be established. Apple required for a licensed in order to have Bluetooth connections to Apple devices. However, the other aspects of the project were established. The scope of the design can be summarized as follows: 1. Provide an alarm and notification device for the deaf/hard hearing people. 2. Implement Bluetooth technology to provide the ability to interface with the Android cellular platform and cellular network. 3. Provide necessary documentation to assist a customer using the device. Concept Selection process The critical customer specifications are shown in the bullet points below: Device must function as an alarm, with the use of high-intensity LED s and a external bed shaker Device must use Bluetooth to communicate with Android devices. Device must have a snooze button Device must deactivate after a reasonable amount of time Alarm must still function when Bluetooth communication is lost Device will be relatively inexpensive in quantities of 500. Device will have indicator LED s for calls, texts, and s. The BlueGiga WT12 Bluetooth module must be utilized The previous iteration of this project utilized a Raspberry pi that contained ARM based processor. In order to reduce product cost we made the decision to switch to the MSP430. We decided to utilize the MSP430 Launchpad development tool. Utilizing the Launchpad allowed us to reduce the production cost significantly with minimal sacrifices. Utilizing the Launchpad also helped to save time designing the PCB. -

3 P13037 Technical Report Page 3 Bluetooth Module and Program The customer required that Bluetooth be the means for communication between the android device and the notification system. From past experience the customer required that a BlueGiga WT12 Bluetooth module was utilized. The WT12 module communicates to the MSP430 using UA+*963 RT, which stands for universal asynchronous receive transmit. From this transmission, the MSP430 receives information from the user which was input into the android app such as alarm time or current time. The software then decodes all the information from the transmission and stores the necessary information. A real time clock is generated from a 32kHz crystal on the MSP430. This was used to generate an accurate clock to keep time on the device. Combining the real time clock and the stored information, the MSP430 can activate an alarm sequence at the predetermined time. This alarm sequence will activate both high intensity LEDs and a bed shaker. The combination of the two stimuli then wakes up the sleeping user. Power Regulation Two power regulator circuits were required to provide power to the high intensity LED s and the notification LED s. To step down the voltage and convert to 12V we utilized a standard 12V 3A Wallwart. To provide the high intensity LED s with the 22V required to operate we utilized a Texas instrument TPS55340 boost regulator chip. The TPS55340 boost regulator will step the 12V from the Wallwart to the 22V required. The notification LED s along with the MSP430 require 3.3V to operate. To step down the 12V to 3.3V we utilized a Texas Instrument TPS62175 Step Down regulator chip. Alarm System The alarm system is composed both a visual and physical stimulus. A standard bed shaker provides a vibration to wake the user. For a visual stimulus we decided to utilize 6 Cree XLAMP MX-6s LED s. Each LED provides 113 lumens at 60mA. The visual stimulus was the focus of our design. We decided to place 2 LED s on the both the top and front and one LED on each side. This design provides light no matter what orientation the unit is. The enable pin of the TPS55340 was connected to the GPIO pin on the MSP430 to allow us to flash the high intensity LED s. For comparison a 60W light bulb produces around 600 lumens. PCB Board All the electrical circuits needed for the device was designed on a single two layered PCB Board. The board houses: High Intensity LED Voltage Regulatory Circuit, High Intensity LED, Notification LED Voltage Regulatory Circuit, Notification LED, and Bed Shaker Connection Circuit. The board was designed separately on the main board with certain amount of space, so that cutting process can be done on the main PCB Board. The main PCB Board was designed with 100mm x 100mm PCB Board size. A voltage supply and ground was drawn on the each circuit layout by having a through hole connection. From this through hole connection a connection to the header can be made for further circuit connection. The signal port from MSP430 was made using a through hole. Some of the resistor connection was also made on the through hole for easy troubleshoot. The PCB Board was ordered from PCBExpress. PCBExpress supplied their own ExpressPCB software for designing the PCB. Copyright 2013 Rochester Institute of Technology

4 Figure 1. PCB Layout Mobile Application The mobile application was developed by the previous project group (P13036). The mobile application (NAS(was developed for use with Android devices. Setting an alarm for the NAS can be accomplished through the mobile application or through the use of the phones default alarm system. Pressing the Sync Alarm button will transfer the alarm information from the default android clock. Only one alarm can be synced at a time. The mobile application has a slider feature that allows the user to change the vibration intensity of the bed shaker. The mobile application also allows users to turn off text notification if they do not want to be disturbed. Figure 2. Mobile Application Interface

5 P13037 Technical Report Page 5 Housing The housing was designed to be stable to put on tablet/phone on top of the device. Therefore, there is no constraint in size as the housing can be designed to be as wide as tablet for the width. The housing was made from a wood box. It was then stained and sealed for a nice finish. Soft wood was chosen as it is easy to be cut to make a hole for the high intensity and notification LED. Results and discussion Figure 3. Housing Design Testing was performed in terms of desired functionality. The PCB layout had multiple errors that required a second board to be ordered. Extensive testing was done on the PCB board to determine that the powerpad of the 22V regulator chip was incorrectly connected to +12V when it needed to be connected to GND. Once the gerber file was updated and the board was ordered the circuit function as designed. Each subsystem of the product was tested individually before bringing together for the final design. PCB testing uncovered multiple errors. Issues were related to wrong footprint sizes for parts, schematic errors and changing of some parts from initial design. After successfully tested for each board s functionality, the overall compartment was then assembled and tested together. Although the bed shaker circuit operated correctly the MSP430 was not able to provide enough power to enable the mosfet. Testing both electrical circuit and software such as programming of MSP430 and Apps required and iterative approach to find and debug the issue. The mobile application ha bugs that would need to be fixed for future development. The app does not function on android although that is the minimum requirement. The app on an android cell phone has security problems that do not allow the application to work. In addition the snooze function was bypassed to allow the snooze button to turn of the alarm. During development a press and hold of the snooze button was designed to shut down the alarm where a single press was to snooze the alarm. Due to errors with the switch oscillation when pressed, the press and hold functionality was removed and the snooze button was set to turn of the alarm. Therefore there is currently no snooze activated, although the code is written to enable the snooze. Copyright 2013 Rochester Institute of Technology

6 Conclusions and recommendations This project was able to achieve most of the customer requirement. Initial requirement such as Bluetooth connection to IOS devices was not established in this project due to the licensing requirement by Apple. Beds shaker was not able to be triggered during the demo was due to not enough current been supplied from MSP430. The remedy for this problem would to be to replace the mosfet with a mosfet that will operate within the MSP430 specifications. For the next upgrade to the project, some recommendations were suggested. Licensing on the Apple s device Bluetooth should be applied for the next project, so that the device may work with IOS devices. The housing for the device should also be designed using better materials besides soft wood. The customer was satisfied with the high intensity brightness and the Bluetooth connection work with the tablet used. Another consideration would be to utilize a different Bluetooth module to reduce the cost further Special thanks to Mark Indovina for assistance in coding. Special thanks to George Slack for helping us with the woodwork on the case.