hal.cpp

00001 /*******************************************************************************
00002  * Copyright (c) 2014 IBM Corporation.
00003  * All rights reserved. This program and the accompanying materials
00004  * are made available under the terms of the Eclipse Public License v1.0
00005  * which accompanies this distribution, and is available at
00006  * http://www.eclipse.org/legal/epl-v10.html
00007  *
00008  * Contributors:
00009  *    IBM Zurich Research Lab - initial API, implementation and documentation
00010  *    Semtech Apps Team       - Modified to support the MBED sx1276 driver
00011  *                              library.
00012  *                              Possibility to use original or Semtech's MBED
00013  *                              radio driver. The selection is done by setting
00014  *                              USE_SMTC_RADIO_DRIVER preprocessing directive
00015  *                              in lmic.h
00016  * /////////////////////////////////////////////////////////////////////////////
00017  *
00018  * Used by Giorgos Tsapparellas for Internet of Things (IoT) smart monitoring
00019  * device for agriculture using LoRaWAN technology.
00020  *
00021  * Date of issued copy: 25 January 2018
00022  *
00023  * Modifications: 
00024  * - Modified to meet SX1272MB2xAS LoRa shield's pin allocations.
00025  *
00026  * Notice that, connectivity for SX1272MB2xAS LoRa shield is allocated as:
00027  * SX1272MB2xAS   MBED Pin
00028  * SCK             D13
00029  * MOSI            D11
00030  * MISO            D12
00031  * NSS             D10
00032  * DIO0            D2
00033  * DIO1            D3
00034  * DIO2            D4
00035  * DIO3            D5
00036  * NRESET          A0
00037  *
00038  * - Added some external comments for meeting good principles of 
00039  *   source code re-usability. 
00040  *******************************************************************************/
00041  
00042 #include "mbed.h"
00043 #include "lmic.h"
00044 #include "mbed_debug.h"
00045 
00046 #if !USE_SMTC_RADIO_DRIVER
00047 
00048 extern void radio_irq_handler( u1_t dio );
00049 
00050 static DigitalOut nss( D10 ); // nss
00051 static SPI spi( D11, D12, D13 ); // ( mosi, miso, sclk )
00052  
00053 static DigitalInOut rst( A0 ); // rst (reset)
00054 static DigitalOut rxtx( A4 ); // rx and tx
00055  
00056 static InterruptIn dio0( D2 ); // dio0
00057 static InterruptIn dio1( D3 ); // dio1
00058 static InterruptIn dio2( D4 ); // dio2 
00059 
00060 /* 
00061  * dio0Irq function of type void.
00062  *
00063  * Input parameters: None
00064  *
00065  */ 
00066 static void dio0Irq( void ) {
00067     radio_irq_handler( 0 );
00068 }// end of dio0Irq function.
00069 
00070 /* 
00071  * dio1Irq function of type void.
00072  *
00073  * Input parameters: None
00074  *
00075  */ 
00076 static void dio1Irq( void ) {
00077     radio_irq_handler( 1 );
00078 }// end of dio1Irq funtion.
00079 
00080 /* 
00081  * dio2Irq function of type void.
00082  *
00083  * Input parameters: None
00084  *
00085  */ 
00086 static void dio2Irq( void ) {
00087     radio_irq_handler( 2 );
00088 }// end of dio2Irq function.
00089 
00090 #endif
00091 
00092 static u1_t irqlevel = 0;
00093 static u4_t ticks = 0;
00094 
00095 static Timer timer;
00096 static Ticker ticker;
00097 
00098 /* 
00099  * reset_timer function of type void.
00100  *
00101  * Input parameters: None
00102  *
00103  */ 
00104 static void reset_timer( void ) {
00105     ticks += timer.read_us( ) >> 6;
00106     timer.reset( );
00107 }// end of reset_timer function.
00108 
00109 /* 
00110  * hal_init function of type void.
00111  *
00112  * Input parameters: None
00113  *
00114  */ 
00115 void hal_init( void ) {
00116      __disable_irq( );
00117      irqlevel = 0;
00118 
00119 #if !USE_SMTC_RADIO_DRIVER
00120     // Configure input lines.
00121     dio0.mode( PullDown );
00122     dio0.rise( dio0Irq );
00123     dio0.enable_irq( );
00124     dio1.mode( PullDown );   
00125     dio1.rise( dio1Irq );
00126     dio1.enable_irq( );
00127     dio2.mode( PullDown );
00128     dio2.rise( dio2Irq );
00129     dio2.enable_irq( );
00130     // Configure reset line.
00131     rst.input( );
00132     // Configure spi.
00133     spi.frequency( 8000000 );
00134     spi.format( 8, 0 );
00135     nss = 1;
00136 #endif
00137     // Configure timer.
00138     timer.start( );
00139     ticker.attach_us( reset_timer, 10000000 ); // reset timer every 10sec
00140      __enable_irq( );
00141 }// end of hal_init function.
00142 
00143 #if !USE_SMTC_RADIO_DRIVER
00144 
00145 /* 
00146  * hal_pin_rxtx function of type void.
00147  *
00148  * Input parameters: unsigned char val
00149  *
00150  */ 
00151 void hal_pin_rxtx( u1_t val ) {
00152     rxtx = !val;
00153 }// end of hal_pin_rxtx function.
00154 
00155 /* 
00156  * hal_pin_nss function of type void.
00157  *
00158  * Input parameters: unsigned char val
00159  *
00160  */ 
00161 void hal_pin_nss( u1_t val ) {
00162     nss = val;
00163 }// end of hal_pin_nss function.
00164 
00165 /* 
00166  * hal_pin_rst function of type void.
00167  *
00168  * Input parameters: unsigned char val
00169  *
00170  */ 
00171 void hal_pin_rst( u1_t val ) {
00172     if( val == 0 || val == 1 )
00173     { // drive pin
00174         rst.output( );
00175         rst = val;
00176     } 
00177     else
00178     { // keep pin floating
00179         rst.input( );
00180     }
00181 }//end of hal_pin_rst function.
00182 
00183 /* 
00184  * hal_spi function of type unsigned char.
00185  *
00186  * Input parameters: unsigned char out
00187  *
00188  * Return: spi out value
00189  */ 
00190 u1_t hal_spi( u1_t out ) {
00191     return spi.write( out );
00192 }// end of hal_spi function.
00193 
00194 #endif
00195 
00196 /* 
00197  * hal_disableIRQs function of type void.
00198  *
00199  * Input parameters: None
00200  *
00201  */ 
00202 void hal_disableIRQs( void ) {
00203     __disable_irq( );
00204     irqlevel++;
00205 }// end of hal_disableIRQs function.
00206 
00207 /* 
00208  * hal_enableIRQs function of type void.
00209  *
00210  * Input parameters: None
00211  *
00212  */ 
00213 void hal_enableIRQs( void ) {
00214     if( --irqlevel == 0 )
00215     {
00216         __enable_irq( );
00217     }
00218 }// end of hal_enableIRQs function.
00219 
00220 /* 
00221  * hal_sleep function of type void.
00222  *
00223  * Input parameters: None
00224  *
00225  */ 
00226 void hal_sleep( void ) {
00227     // NOP
00228 }// end of hal_sleep function.
00229 
00230 /* 
00231  * hal_ticks function of type unsigned int.
00232  *
00233  * Input parameters: None
00234  * Return: t value 
00235  *
00236  */ 
00237 u4_t hal_ticks( void ) {
00238     hal_disableIRQs( );
00239     int t = ticks + ( timer.read_us( ) >> 6 );
00240     hal_enableIRQs( );
00241     return t;
00242 }//end of hal_ticks function.
00243 
00244 /* 
00245  * deltaticks function of type unsigned short.
00246  *
00247  * Input parameters: unsigned int time
00248  * Return: d time
00249  */ 
00250 static u2_t deltaticks( u4_t time ) {
00251     u4_t t = hal_ticks( );
00252     s4_t d = time - t;
00253     if( d <= 0 ) {
00254         return 0;    // in the past
00255     }
00256     if( ( d >> 16 ) != 0 ) {
00257         return 0xFFFF; // far ahead
00258     }
00259     return ( u2_t )d;
00260 }// end of deltaticks function.
00261 
00262 /* 
00263  * hal_waitUntil function of type void.
00264  *
00265  * Input parameters: unsigned int time
00266  *
00267  */ 
00268 void hal_waitUntil( u4_t time ) {
00269     while( deltaticks( time ) != 0 ); // busy wait until timestamp is reached
00270 }// end of hal_waitUntil function.
00271 
00272 /* 
00273  * hal_checkTimer function of type unsigned char.
00274  *
00275  * Input parameters: unsigned int time
00276  * Return: deltaticks time
00277  *
00278  */ 
00279 u1_t hal_checkTimer( u4_t time ) {
00280     return ( deltaticks( time ) < 2 );
00281 }// end of hal_checkTimer function.
00282 
00283 /* 
00284  * hal_failed function of type void.
00285  *
00286  * Input parameters: None
00287  *
00288  */ 
00289 void hal_failed( void ) {
00290     while( 1 );
00291 }// end of hal_failed function.