Flying Sea Glider / Mbed 2 deprecated 2019_10may_firstflight_jcw_nosd

most functionality to splashdwon, find neutral and start mission. short timeouts still in code for testing, will adjust to go directly to sit_idle after splashdown

Dependencies:   mbed MODSERIAL FATFileSystem

LTC1298/ltc1298.cpp@10:085ab7328054, 2017-10-23 (annotated)

Committer:
danstrider
Date:
Mon Oct 23 12:50:53 2017 +0000
Revision:
10:085ab7328054
Parent:
9:d5fcdcb3c89d
Child:
51:c5c40272ecc3
checked out on the hardware

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mkelly10 9:d5fcdcb3c89d 1 #include "ltc1298.hpp"
mkelly10 9:d5fcdcb3c89d 2
danstrider 10:085ab7328054 3 SpiADC::SpiADC(PinName mosi, PinName miso, PinName sclk, PinName csel, PinName led) :
danstrider 10:085ab7328054 4 _spi(mosi, miso, sclk), // mosi, miso, sclk
danstrider 10:085ab7328054 5 adcLed(led), // status led
danstrider 10:085ab7328054 6 cs(csel) // chip select
mkelly10 9:d5fcdcb3c89d 7 {
mkelly10 9:d5fcdcb3c89d 8 }
mkelly10 9:d5fcdcb3c89d 9
danstrider 10:085ab7328054 10 void SpiADC::initialize() {
mkelly10 9:d5fcdcb3c89d 11 //set up the spi bus and frequency
mkelly10 9:d5fcdcb3c89d 12 _spi.format(13,0);
mkelly10 9:d5fcdcb3c89d 13 _spi.frequency(1000000);
danstrider 10:085ab7328054 14
mkelly10 9:d5fcdcb3c89d 15 //chip select high puts ltc1298 in standby
danstrider 10:085ab7328054 16 cs = 1;
danstrider 10:085ab7328054 17
danstrider 10:085ab7328054 18 //zero the initial ch0 and ch1 oversampled readings
mkelly10 9:d5fcdcb3c89d 19 ch0_filt = 0;
mkelly10 9:d5fcdcb3c89d 20 ch1_filt = 0;
mkelly10 9:d5fcdcb3c89d 21
danstrider 10:085ab7328054 22 //led on to say hello
danstrider 10:085ab7328054 23 adcLed = 1;
mkelly10 9:d5fcdcb3c89d 24 }
mkelly10 9:d5fcdcb3c89d 25
danstrider 10:085ab7328054 26 // start an interupt driven trigger of the external ADC
danstrider 10:085ab7328054 27 void SpiADC::start() {
mkelly10 9:d5fcdcb3c89d 28 interval.attach_us(this, &SpiADC::update, 100); //this should be a 10 kHz sample rate
mkelly10 9:d5fcdcb3c89d 29 }
mkelly10 9:d5fcdcb3c89d 30
danstrider 10:085ab7328054 31 // stop the interupt driven trigger
danstrider 10:085ab7328054 32 void SpiADC::stop() {
mkelly10 9:d5fcdcb3c89d 33 interval.detach();
mkelly10 9:d5fcdcb3c89d 34 }
mkelly10 9:d5fcdcb3c89d 35
danstrider 10:085ab7328054 36 void SpiADC::update() {
mkelly10 9:d5fcdcb3c89d 37 //flash the LED
mkelly10 9:d5fcdcb3c89d 38 adcLed = !adcLed;
mkelly10 9:d5fcdcb3c89d 39
mkelly10 9:d5fcdcb3c89d 40 //chip select low starts data conversion
mkelly10 9:d5fcdcb3c89d 41 cs = 0;
danstrider 10:085ab7328054 42
mkelly10 9:d5fcdcb3c89d 43 //the next thing is the input data word
mkelly10 9:d5fcdcb3c89d 44 //it is 4 bits and looks like this
mkelly10 9:d5fcdcb3c89d 45 // | start | single/diff | odd/sign | MSB first/LSB first |
mkelly10 9:d5fcdcb3c89d 46 // if you want single ended on channel 0 MSB first then input 0xD
mkelly10 9:d5fcdcb3c89d 47 // if you want single ended on channel 1 MSB first then input 0xF
mkelly10 9:d5fcdcb3c89d 48
mkelly10 9:d5fcdcb3c89d 49 // get channel 0
mkelly10 9:d5fcdcb3c89d 50 unsigned int byte = _spi.write(0xD);
mkelly10 9:d5fcdcb3c89d 51 //send a dummy byte to receive the data
mkelly10 9:d5fcdcb3c89d 52 unsigned int byte1 = _spi.write(0x0);
mkelly10 9:d5fcdcb3c89d 53 ch0_raw = byte1;
mkelly10 9:d5fcdcb3c89d 54 ch0_filt += (ch0_raw - ch0_filt)/CH0OVERSAMPLE;
mkelly10 9:d5fcdcb3c89d 55
mkelly10 9:d5fcdcb3c89d 56 cs = 1;
mkelly10 9:d5fcdcb3c89d 57 cs = 0;
mkelly10 9:d5fcdcb3c89d 58
mkelly10 9:d5fcdcb3c89d 59 byte = _spi.write(0xF);
mkelly10 9:d5fcdcb3c89d 60 //send a dummy byte to receive the data
mkelly10 9:d5fcdcb3c89d 61 byte1 = _spi.write(0x0);
mkelly10 9:d5fcdcb3c89d 62 ch1_raw = byte1;
mkelly10 9:d5fcdcb3c89d 63 ch1_filt += (ch1_raw - ch1_filt)/CH1OVERSAMPLE;
mkelly10 9:d5fcdcb3c89d 64
mkelly10 9:d5fcdcb3c89d 65 //switch chip select back to high
mkelly10 9:d5fcdcb3c89d 66 cs = 1;
mkelly10 9:d5fcdcb3c89d 67 return ;
mkelly10 9:d5fcdcb3c89d 68 }
mkelly10 9:d5fcdcb3c89d 69
danstrider 10:085ab7328054 70 int SpiADC::readCh0() {
mkelly10 9:d5fcdcb3c89d 71 return ch0_filt;
mkelly10 9:d5fcdcb3c89d 72 }
mkelly10 9:d5fcdcb3c89d 73
danstrider 10:085ab7328054 74 int SpiADC::readCh1() {
mkelly10 9:d5fcdcb3c89d 75 return ch1_filt;
mkelly10 9:d5fcdcb3c89d 76 }