7SegSRDriver.h

00001 /* mbed 7-Segment Display Driver Library (via an 8bit Shift Register)
00002  * Copyright (c) 2011 Paul Law
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020  * THE SOFTWARE.
00021  */
00022 
00023 #ifndef LIB_SSEGSRDRIVER_H
00024 #define LIB_SSEGSRDRIVER_H
00025 
00026 #include "mbed.h"
00027 
00028 #define SSegSRDriver_COMN_ANODE 0
00029 #define SSegSRDriver_COMN_CATHODE 1
00030 
00031 //Char defs: 0123456789AbCdEF
00032 const unsigned char SSegSRDriver_chardefs[16] = {0x3F, 0x6, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x7, 0x7F, 0x6F, 0x77, 0x7C, 0x39, 0x5E, 0x79, 0x71 };
00033 
00034 /** 7-Segment Display Driver class, via a 8-bit shift register (such as the 74HC595)
00035  *
00036  * Display should be hooked up to shift register as follows:
00037  * Q0 : Decimal Point, Q1-Q7 : Segments a-g
00038  *
00039  * Example:
00040  * @code
00041  * #include "mbed.h"
00042  * #include "7SegSRDriver.h"
00043  *
00044  * SSegSRDriver display(p27,p25,p26, SSegSRDriver_COMN_ANODE);
00045  *
00046  * int main() {
00047  *     while (1) {
00048  *         // Show the chars 0-9 then A-F, flashing the decimal point on and off
00049  *         for (int i=0; i<16; i++) {
00050  *             display.write(i,i%2 == 0);
00051  *             wait(1);
00052  *         }
00053  *     }
00054  * }
00055  * @endcode
00056  */
00057 class SSegSRDriver {
00058 
00059 public:
00060 
00061     /** Create a 7-Segment Display Driver object connected to a 8-bit shift register on the given DigitalOut pins
00062      *
00063      * @param srData Shift Register Data pin (DigitalOut)
00064      * @param srClock Shift Register Clock pin (DigitalOut)
00065      * @param srLatch Shift Register Latch pin (DigitalOut)
00066      * @param disp_type Display Type: Common Anode/Cathode (SSegSRDriver_COMN_ANODE (0) or SSegSRDriver_COMN_CATHODE (1))
00067      */
00068     SSegSRDriver(PinName srData, PinName srClock, PinName srLatch, bool disp_type);
00069 
00070     /** Change the type of 7-Segment Display
00071      *
00072      * @param disp_type Display Type: Common Anode/Cathode (SSegSRDriver_COMN_ANODE (0) or SSegSRDriver_COMN_CATHODE (1))
00073      */
00074     void set_type(bool disp_type);
00075     
00076     /** Sets the currently shown digit on the display
00077      *
00078      * @param number The digit to display (0-15) to show numbers 0-9 and letters A-F
00079      */
00080     void write(unsigned char number); 
00081     
00082     /** Sets the currently shown digit on the display along with the decimal place
00083      *
00084      * @param number The digit to display (0-15) to show numbers 0-9 and letters A-F
00085      * @param dp If the decimal place should be lit (0:Off, 1:On)
00086      */
00087     void write(unsigned char number, bool dp);   
00088     
00089     /** Sets the segments of the display directly
00090      * Segments are lit by binary flags where LSB is the decimal point, then segments a-g up to the MSB
00091      * e.g. to light segments e, f and the decimal place = 01100001
00092      *
00093      * @param bValue The segments to light
00094      */
00095     void write_raw(unsigned char number);   // Write directly to the display - Q0/Q1-Q7
00096     
00097     /** Turn all segments of the display off
00098      */
00099     void clear();   // Clears the display
00100     
00101 private:
00102 
00103     DigitalOut _srData;
00104     DigitalOut _srClock;
00105     DigitalOut _srLatch;
00106     bool _disp_type;
00107 };
00108 
00109 #endif