Starting from GBA, walking into the temple (hardware ~ data cable) from ARM (hardware ~ data cable) Home: www.gbaline.com Date: 2004-3-18
1. Write the introduction of the introduction of the basic soft, hardware environment, and related usage methods of learning embedded development, from feedback from the situation, indeed attracting a lot of readers. However, some readers have also put forward objections, they have questions: 1. Developing on GBA means embedded development, it is too narrow! ? 2. ARM development board is also very cheap, and it is more professional, why do you want to use GBA? 3. The clue of GBA is too low, the memory is too small, transplanted above, the development of the operating system is too difficult, not suitable as a gateway platform for ARM.
Before following the topic "hardware ~ data line", it is necessary to explain the above questions, and the reason why the GBA is used as the ARM entry platform, clarify the readers of this series. 1. Functionally, GBA includes functions such as sound processing, color LCD display, and input and output; from the user's point of view, GBA involves human hand, eyes, ear and other sensory organs; from the developer's angle, it is complete Embedded system.
2. The readers of this series of articles are: a). Pure software developers who have no effort to hardware. (Most of the R & D staff in the IT industry belong to this team, including many graduates that are about to enter this industry or a proficiency of IT career). B). Some of the hardware is slightly, but for hardware design, debugging is extremely headache, but also wants to learn the readers of embedded development. C). Emergency, this threshold of hardware, familiar with the software masters of the ARM architecture as soon as possible.
Through the division of the target readers, you should know why the GBA platform should be recommended to the above entry without adopting a professional ARM development board. Because the word "professional" it means that the entry must be high, and the learning is difficult. Of course, special hardware development, or more familiar to hardware, developers with more experienced developers, are not hereby discussed.
As for that some readers think that the development of the operating system is difficult to transplant on GBA, it is considered that ARM should not be used as a gateway platform. For most readers who want to get started, just in contact hardware is to study, develop operating systems, which is not very reality, but also violates the progressive process of simply refinement.
In summary, the main keywords in this series are "entry".
Next, the rules are correct, start this topic "hardware ~ data line", here will teach you how to connect the production of a data cable (focus on circuit connection, need a certain circuit knowledge), this DIY data The maximum transmission rate of the line is about 100kb / s, and the recording 64MBITS scribe card time is about 1 minute for about 1 minute, supporting a variety of compatible card belts.
2. About the data line knows that the computer has entered our lives and is gradually become a necessity for this era. We have to use computers most of our work. How to put your work results on GBA test? Software simulation on the computer? Yes, but it is not possible to fully simulate the real environment of hardware, or you need to run test in a real hardware environment.
In this process, the data line will be used in the field, and the work results can be downloaded to the storage unit of the GBA, and the two-way data exchange of PC <-> GBA can be implemented. Of course, remote debugging can be implemented.
Some people will be confused, and the utility of the data cable is clear. It is used to exchange data, then achieve the principle? Why is the data cable that can be exchanged, this data cable is different from the mobile phone and other computer peripherals? We all know that most electronic devices generally provide electrical interface for exchange data. However, the electrical parameters between the interfaces of different electronic devices are generally different. Therefore, the data lines will be born, and become the physical channel to adapt to the electrical parameters of the two sides, the transmission protocol, in short, is an interface conversion tool. For GBAs we have to use, there are different ways between PCs and GBAs. GBA has only one serial transport port (SIO), while PC has a different type of interface (parallel port, serial port, USB, 1394, etc.), between GBA-PCs, a pair of relationships, we can design and implement according to need Different electrical interface data cable. For example: SiO-parallel port, SiO-serial port, SiO-USB, SIO-1394, etc. Design, it can be based on data transmission rate, economic and other reference factors. Among them, SiO-serial port is the most simple, but the speed is also the slowest, and some people have introduced the principles of such data lines. The SiO-USB and SiO-1394 technologies are more complicated, so only the principles of SiO-parallel data lines are introduced here. 3. Do your hand DIY GBALINE data cable to introduce GBALINE before introducing SIO-parallel data cable, because the following will be used as a reference object.
GBALINE is a data line of the SiO-parallel-port structure. At present, the transfer rate of version 2.0 has reached 150kb / s, and 115kb / s is also 115kb / s, which is a high-speed data cable in the true sense. The following is the principle of GBALINE, wiring diagram: Description: This circuit uses Atmel's AT90S1200-12 chip, the entire circuit is powered by GBA. The computer is the DB25 connector, and the GBA is a SiO connector. Among them, the SIO connector of GBA is shown below:
The correspondence between the pin is: 1. The pin relationship between the GBA-SiO port and the AT90S1200-12 chip is: SiO 1-6 feet correspond to 20, 2, 3, 6, 7, 10 feet of AT90S1200-12, respectively.
2. The Pin relationship between the DB25 joint and the AT90S1200-12 chip is: DB25 16, 17, 11, 15, 13, 12, 10, 2, 3, 4, 5 total 11 pins correspond to 8, 9, 11 of the AT90S1200-12 , 12, 13, 14, 15, 16, 17, 18, 19 pins.
3. XTAL2-XTAL1 is connected to the two feet of the crystal. (The light-emitting diode is connected in series, connected to the 9th foot of DB25 after a resistor, which is used to display whether the circuit is energized, and this part is an optional component.
4. Software about the data cable Because this article is focused on circuit connections, it is not allowed to make a detailed explanation of the circuit implementation principle and software part.
The Firmware of AT90S1200-12 will be pre-recorded in the chip. The software of the PC side uses Vigor Studio. The maximum transmission rate of the DIY data line is about 100kb / s, and the GBALINE can be read and write, and it is also compatible. Recovered refractory card.
5. Reference picture
6. The DIY component provides for the convenience of the reader DIY data cable, we will provide a complete set of dispersion, free of multimeter PCB, can be purchased locally, or without PCB, the wire can be directly soldered on the IC. 1. DB25 connector (LPT header), housing 2. GBA-SiO line 3. AT90S1200-12 chip (including pre-recorded procedures) 4. Related capacitors, resistors, crystal oscillator 5. Matching Vigor Studio software (please download from www.gbaline.com) The entire set of DIY dispensers is 28 yuan. (Optional 64MBITS GBALINE can be wiped, the card is 40 yuan), and the DIY activity only provides a mail delivery service.
