Nrf2401A.cpp

00001 /*
00002  *  Nrf2401A.h
00003  *  A simplistic interface for using Sparkfun's Nrf2401A breakout boards with Arduino
00004  *
00005  *  Ported to mbed by Jas Strong <jasmine@heroicrobotics.com>
00006  *
00007  *  Original code for http://labs.ideo.com by Jesse Tane March 2009
00008  *
00009  *  License:
00010  *  --------
00011  *  This is free software. You can redistribute it and/or modify it under
00012  *  the terms of Creative Commons Attribution 3.0 United States License. 
00013  *  To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/us/ 
00014  *  or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.
00015  *
00016  *  Notes:
00017  *  ------
00018  *  For documentation on how to use this library, please visit http://www.arduino.cc/playground/Main/InterfacingWithHardware
00019  *
00020  */
00021 
00022 #include "Nrf2401A.h"
00023 #include "mbed.h"
00024 
00025 
00026 Nrf2401::Nrf2401(PinName n_DR1, PinName n_CE, PinName n_CS, PinName n_CLK, PinName n_DAT) :
00027     _dr1(n_DR1), _ce(n_CE), _cs(n_CS), _clk(n_CLK), _dat(n_DAT)
00028 {
00029   _dat.output();
00030   
00031   remoteAddress = 0;
00032   localAddress = 0;
00033   payloadSize = 0;
00034   dataRate = 1;
00035   channel = 111;
00036   power = 3;
00037   mode = 0;
00038   
00039   configuration[7] = 234;
00040   configuration[8] = 223;
00041   configuration[9] = 212;
00042   
00043   disable_chip();
00044   deselect_chip();
00045 }
00046 
00047 void Nrf2401::rxMode(unsigned char messageSize)
00048 {
00049   mode = 1;
00050   if(messageSize) payloadSize = messageSize, configure();
00051   else configuration[14] |= 1, loadConfiguration(true);
00052   enable_chip();
00053   wait_us(250);
00054 }
00055 
00056 void Nrf2401::txMode(unsigned char messageSize)
00057 {
00058   mode = 0;
00059   if(messageSize) payloadSize = messageSize, configure();
00060   else configuration[14] &= ~1, loadConfiguration(true);
00061   wait_us(250);
00062 }
00063 
00064 void Nrf2401::write(unsigned char* dataBuffer)
00065 {
00066   if(!dataBuffer) dataBuffer = (unsigned char*) data;
00067   enable_chip();
00068   wait_us(5);
00069   loadByte(configuration[7]);
00070   loadByte(configuration[8]);
00071   loadByte(configuration[9]);
00072   loadByte(remoteAddress >> 8);
00073   loadByte(remoteAddress);
00074   for(int i=0; i<payloadSize; i++) loadByte(dataBuffer[i]);
00075   disable_chip();
00076   wait_us(250);
00077 }
00078 
00079 void Nrf2401::write(unsigned char dataByte)
00080 {
00081   data[0] = dataByte;
00082   write();
00083 }
00084 
00085 void Nrf2401::read(unsigned char* dataBuffer)
00086 {
00087   if(!dataBuffer) dataBuffer = (unsigned char*) data;
00088   disable_chip();
00089   wait_ms(2);
00090   for(int i=0; i<payloadSize; i++)
00091   {
00092     dataBuffer[i] = 0;
00093     for(int n=7; n>-1; n--)
00094     {
00095       if(rx_data_hi()) dataBuffer[i] |= (1 << n);
00096       wait_us(1);
00097       cycle_clock();
00098     }
00099   }
00100   enable_chip();
00101   wait_us(1);
00102 }
00103 
00104 bool Nrf2401::available(void)
00105 {
00106   return data_ready();
00107 }
00108 
00109 //// you shouldn't need to call directly any of the methods below this point...
00110 
00111 void Nrf2401::configure(void)
00112 {
00113   configuration[1] = payloadSize << 3;
00114   configuration[10] = localAddress >> 8;
00115   configuration[11] = localAddress;
00116   configuration[12] = 163;
00117   configuration[13] = power | (dataRate << 5) | 76;
00118   configuration[14] = mode | (channel << 1);
00119   loadConfiguration();
00120 }
00121 
00122 void Nrf2401::loadConfiguration(bool modeSwitchOnly)
00123 {
00124   disable_chip();
00125   select_chip();
00126   wait_us(5);
00127   if(modeSwitchOnly) loadByte(configuration[14]);
00128   else for(int i=0; i<15; i++) loadByte(configuration[i]);
00129   deselect_chip();
00130 }
00131 
00132 void Nrf2401::loadByte(unsigned char byte)
00133 {
00134   for(int i=7; i>-1; i--)
00135   {
00136     if((byte & (1 << i)) == 0) tx_data_lo();
00137     else                       tx_data_hi();
00138     wait_us(1);
00139     cycle_clock();
00140   }
00141 }