LeafLabs Garden » Topic: spi adc help

LeafLabs Garden » Topic: spi adc help http://forums.leaflabs.com/topic.php?id=974 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:17:27 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://forums.leaflabs.com/search.php house91320 on "spi adc help" http://forums.leaflabs.com/topic.php?id=974#post-5996 Tue, 16 Aug 2011 13:10:42 +0000 house91320 5996@http://forums.leaflabs.com/ thanks ill let you guys know mbolivar on "spi adc help" http://forums.leaflabs.com/topic.php?id=974#post-5987 Mon, 15 Aug 2011 19:58:33 +0000 mbolivar 5987@http://forums.leaflabs.com/ quick things to try: - replace Serial with SerialUSB, and delete the "Serial.begin()" line, as recommended here: <a href="http://leaflabs.com/docs/arduino-compatibility.html#sketch-and-library-porting-howto" rel="nofollow">http://leaflabs.com/docs/arduino-compatibility.html#sketch-and-library-porting-howto</a> - delete the #include <SPI.h>, since there's no port for that library yet. replace it with HardwareSPI, which is documented here: <a href="http://leaflabs.com/docs/lang/api/hardwarespi.html#lang-hardwarespi" rel="nofollow">http://leaflabs.com/docs/lang/api/hardwarespi.html#lang-hardwarespi</a> to get going quickly, i would just add the line <code>HardwareSPI SPI(1);</code> before your setup(), since you appear to be using SPI1. there are HardwareSPI methods which are equivalent to the SPI methods you're calling, so this should "just work". everything else seems like it should be compatible between maple and arduino; let us know how you get along! house91320 on "spi adc help" http://forums.leaflabs.com/topic.php?id=974#post-5977 Fri, 12 Aug 2011 15:49:07 +0000 house91320 5977@http://forums.leaflabs.com/ I was wondering if anyone could give me some help porting this to the maple? #include <SPI.h> #define MISOPIN 12 #define SCLKPIN 13 byte byte1; byte byte2; byte byte3; // declare 3 bytes = 24 bits void setup() { Serial.begin(9600); pinMode(SCLKPIN, OUTPUT); pinMode(MISOPIN, INPUT); // corresponding to SCK pin and DRDY/DOUT pin on ADC reset_adc(); // put ADC on reset at the outset SPI.begin(); // initialize SPI (with default settings, including... // CPOL = 0: so that SCLK is normally LOW // CPHA = 0: data sampled on rising edge (LOW to HIGH) // perhaps try changing CPHA ?? digitalWrite(SCLKPIN, LOW); // release ADC from reset; now we're at a known point // in the timing diagram, and just have to wait for // the beginning of a conversion cycle } void loop() { if (digitalRead(MISOPIN) == HIGH) read_adc(); // "sort of" an interrupt to go to read_adc routine; // can use hardware interrupt in future but now just poll } void reset_adc() // to reset ADC, we need SCLK HIGH for min of 4 CONVCYCLES // so here, hold SCLK HIGH for 5 CONVCYCLEs = 1440 usec { digitalWrite(SCLKPIN, HIGH); delayMicroseconds(1440); } void read_adc() { drdy_wait(); // go to drdy_wait routine, where we wait for // DRDY phase to pass, and thus for DOUT phase to begin byte1 = SPI.transfer(0x00); byte2 = SPI.transfer(0x00); byte3 = SPI.transfer(0x00); // read in adc data (sending out don't care bytes) // and store read data into three bytes */ Serial.println(byte1, DEC); Serial.println(byte2, DEC); Serial.println(byte3, DEC); Serial.println(); // print out data; // will these instructions eat into time significantly? // possible improvement: store all data from multiple cycles // into array, and print out only later at end. } void drdy_wait() // wait for DRDY to pass and to reach start-point of DOUT { delayMicroseconds(30); // to be safe, 30 usec, instead of 27 usec, which is // the expected period of DRDY phase } thanks