Kommentar: Einfügen von HTML im Kommentar: Link einfügen: <a href="LINKURL" target="_blank">LINKTITEL</a> Bild einfügen: <img src="BILDURL"> Text formatieren: <b>fetter Text</b> <i>kursiver Text</i> <u>unterstrichener Text</u> Kombinationen sind auch möglich z.B.: <b><i>fetter & kursiver Text</i></b> C Quellcode formatieren: <code>Quellcode</code> BASIC Quellcode formatieren: <basic>Quellcode</basic> (Innerhalb eines Quellcodeabschnitts ist kein html möglich.) Wichtig: Bitte mache Zeilenumbrüche, bevor Du am rechten Rand des Eingabefeldes ankommst ! -> I > > Hi all, > > > > I want to try a new project with my Probot128 to record and play back > > sounds. I can record microphone samples with 7200 Hz with ADC in free > > running mode. But I cannot store the samples fast enough because there > > is only 4 kB SRAM and EEPROM via I2C is too slow. That is why I am > > considering extending my robot with extra SRAM via SPI. The question > > is, is SPI fast enough? > > In assembler surely SPI would be fast enough, but that would probably > > be too difficult for me to program. Could someone tell me how fast SPI > > is via the byte interpreter commands? How long take SPI_Write() and > > SPI_Read()? > > > > Thanks for any help. > > Regards, > > Pepe > > Hallo Pepe, > > it is a good idea to give the C-Controlsystem more fast memory > which we can manage ourselves, and not only for the ProBot128. > But I would not recommend to use the functions "SPI_Write(...)" > and "SPI_Read(...)" to send several datas. I think it is better > to use the function "SPI_WriteBuf(...)". The SPI-interface is > also very simple to use in assembler. I did a few measurements > with the code below. Look at the file "SPITest-0.01.zip". > > > Using double speed (prescaler = 2) we have: > 7.37 Mbit/s > SCK cycle = 2 cpu cycles = 136 ns > > The time to send 20 bytes is whith the: > bytecodeinterpreter = ca. 60 µs > assembler call = 38.658 µs > > The time between 2 bytes is by the: > bytecodeinterpreter = 20 µs ?;-(|-< > assembler version = 1.2 µs > > These times are only the communication-times without the > time for the function calls. > > Gruß Torsten. >
