The Research and Implementation of Vehicle Bluetooth Hands-free Devices Key Parameters Downloading Algorithm

Transcription

1 Available online at Physics Procedia 25 (2012 ) International Conference on Solid State Devices and Materials Science The Research and Implementation of Vehicle Bluetooth Hands-free Devices Key Parameters Downloading Algorithm ZHAG Xiao-bo, WAG Zhi-xue, LI Jian-xin, MA Jian-hui, LI ang, LI an-qiang Shandong Provincial Key Laboratory of Automotive Electronic Technology Institute of Automation, Shandong Academy of Sciences Jinan, Shandong Province, China Abstract In order to facilitate Bluetooth function realization and information can be effectively tracked in the process of production, the vehicle Bluetooth hands-free devices need to download such key parameters as Bluetooth address, CVC license and base plate numbers, etc. Therefore, it is the aim to search simple and effective methods to download parameters for each vehicle Bluetooth hands-free device, and to control and record the use of parameters. In this paper, by means of Bluetooth Serial Peripheral Interface programmer device, the parallel port is switched to SPI. The first step is to download parameters is simulating SPI with the parallel port. To perform SPI function, operating the parallel port in accordance with the SPI timing. The next step is to achieve SPI data transceiver functions according to the programming parameters of options. Utilizing the new method, downloading parameters is fast and accurate. It fully meets vehicle Bluetooth hands-free devices production requirements. In the production line, it has played a large role Published by Elsevier Ltd. B.V. Selection and/or peer-review under responsibility of of [name Garry organizer] Lee Open access under CC B-C-D license. Keywords: SPI, CVC License, LAP I. Introduction In recent years, more and more car owners begin to attach importance to the safety and ease of talking on the phone while driving [1]. The vehicle Bluetooth hands-free devices gradually prevailed in many countries. By means of the vehicle Bluetooth hands-free devices, drivers can answer the phone by Bluetooth hands-free calls. So security can get ensuring, their hearing can avoid be ruined with earphones. And the effect of mobile phone radiation is at greatly reduced Published by Elsevier B.V. Selection and/or peer-review under responsibility of Garry Lee Open access under CC B-C-D license. doi: /j.phpro

2 1092 Zhang Xiao-bo et al. / Physics Procedia 25 ( 2012 ) As a Bluetooth product, the vehicle Bluetooth hands-free devices must have a globally unique Bluetooth address. Each product has only base plate numbers which are in one to one corresponding to Bluetooth address. Otherwise, drivers are not allowed to answer the phone by hand in many countries for the pursuit of driving safety. It provides a wide market for vehicle Bluetooth hands-free devices using Bluetooth technology. To realize the vehicle Bluetooth hands-free functions listing, one of the important problems to be solved is Bluetooth technology. Another one is the quality of voice communication, which includes echo and noise problem inside an automobile [2-4]. To reduce noise and remove undesired echoes, the vehicle Bluetooth hands-free devices adopt CSR s CVC algorithm. Because CVC license is necessary for the algorithm parameters, it must also be downloaded to the vehicle Bluetooth hands-free devices. It can be seen that the essential procedure during production is to download such key parameters as Bluetooth address, CVC license and base plate numbers, etc. For manufacturers, the Bluetooth address is a logo which the vehicle Bluetooth hands-free device is affiliated with the company [5]. Bluetooth address and CVC license is two big input costs. Therefore, it is necessary to strictly control the use of Bluetooth address and CVC license and to record the use of parameters for each vehicle Bluetooth hands-free device. Artificial record is not advisable in the existing production line. Therefore, two of the important problems to be solved are to download parameters for each vehicle Bluetooth hands-free device, and to control and record the use of parameters. 2. The key parameters download algorithm The vehicle Bluetooth hands-free devices use CSR Bluetooth single-chip, which download parameters by SPI. By means of Bluetooth SPI programmer device, the parallel port is switched to SPI. The connect signals between Bluetooth SPI programmer device and the vehicle Bluetooth hands-free device include GD, MOSI, MISO, CSB, CLK, VCC-3.3. When in use, connect one end of Bluetooth SPI programmer device to the vehicle Bluetooth hands-free device, the other end to PC Parallel Port. Bluetooth SPI programmer device will be powered by the vehicle Bluetooth hands-free device. Finally, power on the vehicle Bluetooth hands-free device, and be ready to download key parameters. The vehicle Bluetooth hands-free device key parameters downloading algorithm as shown in Figure 1. There are two major steps in the realization of downloading parameters. The first step is to download parameters is simulating SPI with the parallel port. To perform SPI function, operating the parallel port in accordance with the SPI timing. The next step is to achieve SPI data transceiver functions according to the programming parameters of options. The following is the main realization method.

3 Zhang Xiao-bo et al. / Physics Procedia 25 ( 2012 ) Connect to Bluetooth SPI programmer device Set CVC license Judge CVC license s legality Input base plate numbers Judge base plate number s legality Input Bluetooth address Judge Bluetooth address s legality Establish SPI connection Write Bluetooth address Download the next device Write base plate numbers Write CVC license Warm Reset Read-back check Bluetooth address and base plate numbers Update writing log Fig. 1 Vehicle Bluetooth hands-free devices key parameters downloading algorithm 1) Before Bluetooth device s production, the manufacturers need buy Bluetooth address from SIG association, and then provide Bluetooth address to CSR in order to generate the corresponding CVC license. In general, CSR generate only one CVC license for a number of Bluetooth addresses. In other words, it is one many-to-one relationship between Bluetooth address and CVC license. Therefore, we should set CVC license and judge whether it is legal before download one batch of device parameters. If not, you are warned to reset CVC license. 2) Input 12-bit base plate number, and judge whether it is legal. If not, you are warned to try again. Due to the parameter must be downloaded to the device in uint16 format, so the base plate number

4 1094 Zhang Xiao-bo et al. / Physics Procedia 25 ( 2012 ) preprocessing is essential. The preprocessing algorithm is shown in Figure 2. And the algorithm has written as in the following script. // BEGI tempstring = m_id; tempstring.trimleft(); tempstring.trimright(); idstr=tempstring; if(tempstring.getlength() == 12) k=0; while(k<6) cid = tempstring.getat(2*k); // Get the previous character i1= cid; // Get the previous character s ASCII value cid = tempstring.getat(2*k+1); //Get the next character i2 = cid; // Get the next character s ASCII value i1=i1<<8; id[k]=i1 + i2; k = k+1; } } // ED 3) Input Bluetooth address. Each Bluetooth product is allocated a unique 48-bit device address [6-9]. It is divided into a 24-bit LAP field, a 16-bit AP field and an 8-bit UAP field. Bluetooth address is printed on stickers which are attached to the Bluetooth product. So it can be read easily by barcode scanner. The next, judge whether it is legal, including whether the Bluetooth address is already recorded in writing log. If not, you are warned to reset it again. This can avoid that different products are downloaded to the same Bluetooth address, so as to ensure that the product has the only global Bluetooth address. If the address is legal, the necessary SPI connection will be established. 4) If the SPI connection is established successfully, the vehicle Bluetooth hands-free devices will download in turn such key parameters as Bluetooth address, CVC license and base plate numbers, etc. 5) After it has finished downloading, warm reset the device. CSR Bluetooth single-chip must be reset after the key parameters are successfully downloaded. Otherwise, the three key parameters won't really play a role. If Bluetooth address remains disabled, Bluetooth function testing won't be begun. This is because Bluetooth address is used for locating the under-test device. By warm reset, the SPI connection is still available after reset successfully. We must ensure that the SPI connection is available during the whole of testing. 6) To ensure that the key parameters is no wrong, we need to Read-back and check both Bluetooth address and base plate numbers after reset has succeeded. Compared with two input values, if not equal, then the process starts all over again. Read-back and check base plate numbers has written as in the following script. // begin to Read-back and check base plate numbers idstr=""; if(id_result==1) // Read-back successfully

5 Zhang Xiao-bo et al. / Physics Procedia 25 ( 2012 ) } //end for(int k =0; k < 6;k++) // Get the previous character s ASCII value i1=id[k]&(0xff00); i1=i1>>8; idstr = idstr+(char)i1; // Get the next character s ASCII value i2=id[k]&(0x00ff); idstr = idstr+(char)i2; } Input the plate number(idstr) GetLength (idstr)= =12? K=0; cid =idstr.getat(2*k); // Get the previous character i1= cid; // Get the previous character sasciivalue i1=i1<<8; id[k] cid = idstr.getat(2*k+1); //Get the next character i2 = cid; // Get the next character s ASCII value k = k+1; K<6? Continue Fig. 2 The preprocessing algorithm 7) Update writing log. This is a step that the key parameters are automatically recorded in the EXCEL file. It ensures accurate and effective grasp of production as well as address utilization each day.

6 1096 Zhang Xiao-bo et al. / Physics Procedia 25 ( 2012 ) Conclusion Practice proves that the method downloading parameters is fast and accurate. The key parameters are automatically recorded in the writing log. It gives enterprises better control over Bluetooth address, thus avoiding resources wasting. This process can fully satisfy the requirement of production. Acknowledgment R.B.G. thanks Shandong Province Key Laboratory of Automotive Electronic Technology--- Shandong province of major scientific and technological special project Development and industrialization of car body network and electronic products interrelated ECU (the project number: 2007ZHZX10503). References [1] Xiao Wei, ang Tao. Core Architecture of Bluetooth Technology, Telecommunications Science, 2001(1): [2] DOG Li-jun, FAG Chao, QI Ran,LIU Xiao-ming, SHE Lian-feng. Research and realization of embedded Bluetooth gateway for voice communication, Journal of Chongqing University of Posts and Telecommunications, 2005, 17(4):1-5. [3] Ma Jian-hui, Ma Gong-li, Deng Li-bao. Application of Bluetooth Technology in Automotive Infotainment System, Electronic Design & Application World for Design and Application Engineers, [4] LIAG Qi-jun,WU Xi-lan,FA Xin. Design of wireless teaching aided tool PPTCtrl with Bluetooth SmartPhone, Computer Engineering and Design, 2010, 31(7): [5] A El-Hoiydi. Interference between Bluetooth etworks-upper Bound on the Packet Error Rate[J].IEEE Commun. Lett. (S ), 2001, 5(6): [6] Brian S Peterson, Rusty O Baldwin, Jeffrey P Kharoufeh, et al.refinements to the Packet Error Rate Upper Bound for Bluetooth etworks[j].ieee Commun. Lett. (S ), 2003, 7(8): [7] Fredrik Florén, AndréStranne, Ove Edfors, et al. Throughput of Strongly Interfering Slow Frequency-Hopping etworks[j].ieee transactions on communications(s ),2004,52(7): [8] Saswati Sarkar, Farooq Anjum, Ratul Guha. Optimal Communication in Bluetooth Piconets[J].IEEE Transaction on Vehicular Technology(S ),2005,54(2): [9] Borja Gomez Zarce?o.Mobile applications with J2ME and JSR82:Bluetooth enabled Java applications for mobile phones[z].acs Seminar,2004.