Stephen Wilkins / TPixy-Interface

A library for interfacing with the Pixy color recognition camera

Dependents:   PixyCamera MbedOS_Robot_Team ManualControlFinal PlayBack ... more

TPixyInterface.cpp@0:ef0e3c67dc5b, 2016-03-14 (annotated)

Committer:
swilkins8
Date:
Mon Mar 14 00:35:23 2016 +0000
Revision:
0:ef0e3c67dc5b
Completed rewrite of code to expand interfacing options

Who changed what in which revision?

UserRevisionLine numberNew contents of line
swilkins8 0:ef0e3c67dc5b 1 #include "TPixyInterface.h"
swilkins8 0:ef0e3c67dc5b 2
swilkins8 0:ef0e3c67dc5b 3 PixyInterfaceSPI::PixyInterfaceSPI(SPI* interface) : TPixyInterface(), spi(interface) {}
swilkins8 0:ef0e3c67dc5b 4
swilkins8 0:ef0e3c67dc5b 5 void PixyInterfaceSPI::init()
swilkins8 0:ef0e3c67dc5b 6 {
swilkins8 0:ef0e3c67dc5b 7 spi->frequency(1000000);
swilkins8 0:ef0e3c67dc5b 8 }
swilkins8 0:ef0e3c67dc5b 9
swilkins8 0:ef0e3c67dc5b 10 uint16_t PixyInterfaceSPI::getWord()
swilkins8 0:ef0e3c67dc5b 11 {
swilkins8 0:ef0e3c67dc5b 12 // ordering is different (big endian) because Pixy is sending 16 bits through SPI
swilkins8 0:ef0e3c67dc5b 13 // instead of 2 bytes in a 16-bit word as with I2C
swilkins8 0:ef0e3c67dc5b 14 uint16_t w;
swilkins8 0:ef0e3c67dc5b 15 if (inQ.read(&w)) {
swilkins8 0:ef0e3c67dc5b 16 return w;
swilkins8 0:ef0e3c67dc5b 17 }
swilkins8 0:ef0e3c67dc5b 18 return getWordHw();
swilkins8 0:ef0e3c67dc5b 19 }
swilkins8 0:ef0e3c67dc5b 20
swilkins8 0:ef0e3c67dc5b 21 uint8_t PixyInterfaceSPI::getByte()
swilkins8 0:ef0e3c67dc5b 22 {
swilkins8 0:ef0e3c67dc5b 23 //return SPI.transfer(0x00);
swilkins8 0:ef0e3c67dc5b 24 return spi->write(0x00);
swilkins8 0:ef0e3c67dc5b 25 }
swilkins8 0:ef0e3c67dc5b 26
swilkins8 0:ef0e3c67dc5b 27 int8_t PixyInterfaceSPI::send(uint8_t *data, uint8_t len)
swilkins8 0:ef0e3c67dc5b 28 {
swilkins8 0:ef0e3c67dc5b 29 int i;
swilkins8 0:ef0e3c67dc5b 30 // check to see if we have enough space in our circular queue
swilkins8 0:ef0e3c67dc5b 31 if (outQ.freeLen() < len) {
swilkins8 0:ef0e3c67dc5b 32 return -1;
swilkins8 0:ef0e3c67dc5b 33 }
swilkins8 0:ef0e3c67dc5b 34 for (i = 0; i < len; i++) {
swilkins8 0:ef0e3c67dc5b 35 outQ.write(data[i]);
swilkins8 0:ef0e3c67dc5b 36 }
swilkins8 0:ef0e3c67dc5b 37 flushSend();
swilkins8 0:ef0e3c67dc5b 38 return len;
swilkins8 0:ef0e3c67dc5b 39 }
swilkins8 0:ef0e3c67dc5b 40
swilkins8 0:ef0e3c67dc5b 41 void PixyInterfaceSPI::setArg(uint16_t arg) {}
swilkins8 0:ef0e3c67dc5b 42
swilkins8 0:ef0e3c67dc5b 43 uint16_t PixyInterfaceSPI::getWordHw()
swilkins8 0:ef0e3c67dc5b 44 {
swilkins8 0:ef0e3c67dc5b 45 // ordering is different (big endian) because Pixy is sending 16 bits through SPI
swilkins8 0:ef0e3c67dc5b 46 // instead of 2 bytes in a 16-bit word as with I2C
swilkins8 0:ef0e3c67dc5b 47 uint16_t w;
swilkins8 0:ef0e3c67dc5b 48 uint8_t c, c_out = 0;
swilkins8 0:ef0e3c67dc5b 49
swilkins8 0:ef0e3c67dc5b 50 if (outQ.read(&c_out)) {
swilkins8 0:ef0e3c67dc5b 51 w = spi->write(PIXY_SYNC_BYTE_DATA);
swilkins8 0:ef0e3c67dc5b 52 //w = SPI.transfer(PIXY_SYNC_BYTE_DATA);
swilkins8 0:ef0e3c67dc5b 53 } else {
swilkins8 0:ef0e3c67dc5b 54 w = spi->write(PIXY_SYNC_BYTE);
swilkins8 0:ef0e3c67dc5b 55 //w = SPI.transfer(PIXY_SYNC_BYTE);
swilkins8 0:ef0e3c67dc5b 56 }
swilkins8 0:ef0e3c67dc5b 57 w <<= 8;
swilkins8 0:ef0e3c67dc5b 58 c = spi->write(c_out);
swilkins8 0:ef0e3c67dc5b 59 //c = SPI.transfer(cout);
swilkins8 0:ef0e3c67dc5b 60 w |= c;
swilkins8 0:ef0e3c67dc5b 61 return w;
swilkins8 0:ef0e3c67dc5b 62 }
swilkins8 0:ef0e3c67dc5b 63
swilkins8 0:ef0e3c67dc5b 64 void PixyInterfaceSPI::flushSend()
swilkins8 0:ef0e3c67dc5b 65 {
swilkins8 0:ef0e3c67dc5b 66 uint16_t w;
swilkins8 0:ef0e3c67dc5b 67 while(outQ.len) {
swilkins8 0:ef0e3c67dc5b 68 w = getWordHw();
swilkins8 0:ef0e3c67dc5b 69 inQ.write(w);
swilkins8 0:ef0e3c67dc5b 70 }
swilkins8 0:ef0e3c67dc5b 71 }
swilkins8 0:ef0e3c67dc5b 72
swilkins8 0:ef0e3c67dc5b 73
swilkins8 0:ef0e3c67dc5b 74
swilkins8 0:ef0e3c67dc5b 75
swilkins8 0:ef0e3c67dc5b 76 template <class BufType> CircularQ<BufType>::CircularQ()
swilkins8 0:ef0e3c67dc5b 77 {
swilkins8 0:ef0e3c67dc5b 78 len = 0;
swilkins8 0:ef0e3c67dc5b 79 writeIndex = 0;
swilkins8 0:ef0e3c67dc5b 80 readIndex = 0;
swilkins8 0:ef0e3c67dc5b 81 }
swilkins8 0:ef0e3c67dc5b 82
swilkins8 0:ef0e3c67dc5b 83 template <class BufType> bool CircularQ<BufType>::read(BufType *c)
swilkins8 0:ef0e3c67dc5b 84 {
swilkins8 0:ef0e3c67dc5b 85 if (len) {
swilkins8 0:ef0e3c67dc5b 86 *c = buf[readIndex++];
swilkins8 0:ef0e3c67dc5b 87 len--;
swilkins8 0:ef0e3c67dc5b 88 if (readIndex == PIXY_BUF_SIZE) {
swilkins8 0:ef0e3c67dc5b 89 readIndex = 0;
swilkins8 0:ef0e3c67dc5b 90 }
swilkins8 0:ef0e3c67dc5b 91 return true;
swilkins8 0:ef0e3c67dc5b 92 } else {
swilkins8 0:ef0e3c67dc5b 93 return false;
swilkins8 0:ef0e3c67dc5b 94 }
swilkins8 0:ef0e3c67dc5b 95 }
swilkins8 0:ef0e3c67dc5b 96
swilkins8 0:ef0e3c67dc5b 97 template <class BufType> uint8_t CircularQ<BufType>::freeLen()
swilkins8 0:ef0e3c67dc5b 98 {
swilkins8 0:ef0e3c67dc5b 99 return PIXY_BUF_SIZE - len;
swilkins8 0:ef0e3c67dc5b 100 }
swilkins8 0:ef0e3c67dc5b 101
swilkins8 0:ef0e3c67dc5b 102 template <class BufType> bool CircularQ<BufType>::write(BufType c)
swilkins8 0:ef0e3c67dc5b 103 {
swilkins8 0:ef0e3c67dc5b 104 if (freeLen() == 0) {
swilkins8 0:ef0e3c67dc5b 105 return false;
swilkins8 0:ef0e3c67dc5b 106 }
swilkins8 0:ef0e3c67dc5b 107 buf[writeIndex++] = c;
swilkins8 0:ef0e3c67dc5b 108 len++;
swilkins8 0:ef0e3c67dc5b 109 if (writeIndex == PIXY_BUF_SIZE) {
swilkins8 0:ef0e3c67dc5b 110 writeIndex = 0;
swilkins8 0:ef0e3c67dc5b 111 }
swilkins8 0:ef0e3c67dc5b 112 return true;
swilkins8 0:ef0e3c67dc5b 113 }