6611 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:04:00 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=10392#post-22944 Thu, 14 Mar 2013 20:13:27 +0000 gbulmer 22944@http://forums.leaflabs.com/ <p>superprp - it doesn't really matter what clock rate the two processors are running at. </p> <p>Only one MCU provides the SPI clock, and the other is a slave, and hence the slave simply receives the master's clock.</p> <p>So, the clock from the master must be slow enough for the slave, then the slave will clock data in and out of its shift register using the masters clock signal.</p> <p>Also, you can get the communication working at slow speed, and then speed it up when everything is working. </p> http://forums.leaflabs.com/topic.php?id=10392#post-22942 Thu, 14 Mar 2013 17:15:20 +0000 superprp 22942@http://forums.leaflabs.com/ <p>Hi!</p> <p>I am trying to comunicate a maple with arduino throught SPI (due to I cant comunicate in I2C with maple as slave) and I have one doubt.<br /> How it works if frecuency in MAPLE is 72Mhz and in arduino is 16Mhz? Could I modify this to use the 8Mhz clock in MAPLE x 2 to get 16Mhz? Because if not, following documentation it is like this:</p> <p>MAPLE:</p> <p>Values:</p> <p> SPI_18MHZ = 0 -</p> <p> 18 MHz<br /> SPI_9MHZ = 1 -</p> <p> 9 MHz<br /> SPI_4_5MHZ = 2 -</p> <p> 4.5 MHz<br /> SPI_2_25MHZ = 3 -</p> <p> 2.25 MHz<br /> SPI_1_125MHZ = 4 -</p> <p> 1.125 MHz<br /> SPI_562_500KHZ = 5 -</p> <p> 562.500 KHz<br /> SPI_281_250KHZ = 6 -</p> <p> 281.250 KHz<br /> SPI_140_625KHZ = 7 -</p> <p> 140.625 KHz</p> <p>ARDUINO:</p> <p> SPI_CLOCK_DIV2 = 8Mhz<br /> SPI_CLOCK_DIV4 = 4Mhz<br /> SPI_CLOCK_DIV8 = 2Mhz<br /> SPI_CLOCK_DIV16 = 1Mhz<br /> SPI_CLOCK_DIV32 = 500khz<br /> SPI_CLOCK_DIV64 = 250KHz<br /> SPI_CLOCK_DIV128 = 125Khz </p>