drivers/displays/segment/as1115/as1115.c

   1 /**************************************************************************/
   2 /*!
   3     @file     as1115.c
   4     @author   K. Townsend (microBuilder.eu)
   5
   6     @brief    Drivers for the AS1115 I2C LED/segment-display driver
   7
   8     @section LICENSE
   9
  10     Software License Agreement (BSD License)
  11
  12     Copyright (c) 2012, microBuilder SARL
  13     All rights reserved.
  14
  15     Redistribution and use in source and binary forms, with or without
  16     modification, are permitted provided that the following conditions are met:
  17     1. Redistributions of source code must retain the above copyright
  18     notice, this list of conditions and the following disclaimer.
  19     2. Redistributions in binary form must reproduce the above copyright
  20     notice, this list of conditions and the following disclaimer in the
  21     documentation and/or other materials provided with the distribution.
  22     3. Neither the name of the copyright holders nor the
  23     names of its contributors may be used to endorse or promote products
  24     derived from this software without specific prior written permission.
  25
  26     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  27     EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  28     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  29     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
  30     DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  31     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  32     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  33     ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36 */
  37 /**************************************************************************/
  38 #include "as1115.h"
  39 #include "core/systick/systick.h"
  40
  41 extern volatile uint8_t   I2CMasterBuffer[I2C_BUFSIZE];
  42 extern volatile uint8_t   I2CSlaveBuffer[I2C_BUFSIZE];
  43 extern volatile uint32_t  I2CReadLength, I2CWriteLength;
  44
  45 static bool _as1115Initialised = false;
  46
  47 /**************************************************************************/
  48 /*!
  49     @brief  Sends a single command byte over I2C to the specified address
  50 */
  51 /**************************************************************************/
  52 as1115Error_t as1115WriteCmd (uint8_t address, uint8_t cmd)
  53 {
  54   // Clear write buffers
  55   uint32_t i;
  56   for ( i = 0; i < I2C_BUFSIZE; i++ )
  57   {
  58     I2CMasterBuffer[i] = 0x00;
  59   }
  60
  61   // ToDo: Add real I2C error checking
  62   I2CWriteLength = 2;
  63   I2CReadLength = 0;
  64   I2CMasterBuffer[0] = address;               // device sub address
  65   I2CMasterBuffer[1] = cmd;                   // Command register
  66   i2cEngine();
  67   return AS1115_ERROR_OK;
  68 }
  69
  70 /**************************************************************************/
  71 /*!
  72     @brief  Writes an command byte followed by a data byte over I2C
  73 */
  74 /**************************************************************************/
  75 as1115Error_t as1115WriteCmdData (uint8_t address, uint8_t cmd, uint8_t data)
  76 {
  77   // Clear write buffers
  78   uint32_t i;
  79   for ( i = 0; i < I2C_BUFSIZE; i++ )
  80   {
  81     I2CMasterBuffer[i] = 0x00;
  82   }
  83
  84   // ToDo: Add real I2C error checking
  85   I2CWriteLength = 3;
  86   I2CReadLength = 0;
  87   I2CMasterBuffer[0] = address;               // I2C device address
  88   I2CMasterBuffer[1] = cmd;                   // Command register
  89   I2CMasterBuffer[2] = data;                  // Value to write
  90   i2cEngine();
  91   return AS1115_ERROR_OK;
  92 }
  93
  94 /**************************************************************************/
  95 /*!
  96     @brief  Reads a single byte over I2C
  97 */
  98 /**************************************************************************/
  99 as1115Error_t as1115Read8(uint8_t address, uint8_t *value)
 100 {
 101   // Clear write buffers
 102   uint32_t i;
 103   for ( i = 0; i < I2C_BUFSIZE; i++ )
 104   {
 105     I2CMasterBuffer[i] = 0x00;
 106   }
 107
 108   // ToDo: Add real I2C error checking
 109   I2CWriteLength = 0;
 110   I2CReadLength = 1;
 111   I2CMasterBuffer[0] = address | AS1115_READBIT;
 112   i2cEngine();
 113
 114   *value = I2CSlaveBuffer[0];
 115
 116   return AS1115_ERROR_OK;
 117 }
 118
 119 /**************************************************************************/
 120 /*!
 121     @brief  Initialises the I2C block
 122 */
 123 /**************************************************************************/
 124 as1115Error_t as1115Init(void)
 125 {
 126   // Initialise I2C
 127   if (i2cInit(I2CMASTER) == false)
 128   {
 129     return AS1115_ERROR_I2CINIT;    /* Fatal error */
 130   }
 131
 132   // Reset AS1115 to normal operation with default settings
 133   as1115WriteCmdData(AS1115_ADDRESS, AS1115_SHUTDOWN, 0x01);
 134
 135   // Use user-set I2C address (000000 + address pins)
 136   as1115WriteCmdData(AS1115_ADDRESS, AS1115_SELFADDR, 0x01);
 137
 138   systickDelay(20);
 139
 140   // Use hex decoding
 141   as1115SetDecodeMode(0);
 142
 143   // Set the brightness to the maximum value (0x0F)
 144   as1115SetBrightness(0xF);
 145
 146   // Turn on all digits by default (0..7)
 147   as1115WriteCmdData(AS1115_SUBADDRESS, AS1115_SCANLIMIT, 0x07);
 148
 149   _as1115Initialised = true;
 150
 151   return AS1115_ERROR_OK;
 152 }
 153
 154 /**************************************************************************/
 155 /*!
 156     @brief  Send test command
 157 */
 158 /**************************************************************************/
 159 as1115Error_t as1115Test(void)
 160 {
 161   as1115Error_t error = AS1115_ERROR_OK;
 162   uint8_t results;
 163
 164   if (!_as1115Initialised) as1115Init();
 165
 166   // Use test register to detect LED status
 167   error = as1115WriteCmd(AS1115_SUBADDRESS, AS1115_DISPTEST);
 168   if (error) return error;
 169
 170   error = as1115Read8(AS1115_SUBADDRESS, &results);
 171   if (error) return error;
 172
 173   // Throw an error since something is wrong with the wiring (use 'results' to check)
 174   if ((results & 0xF8) != 0x80)
 175   {
 176     return AS1115_ERROR_UNEXPECTEDRESPONSE;
 177   }
 178
 179   // Turn everything on
 180   error = as1115WriteCmdData(AS1115_SUBADDRESS, AS1115_DISPTEST, 0x01);
 181   if (error) return error;
 182   systickDelay(1000);
 183
 184   // Turn everything off
 185   error = as1115WriteCmdData(AS1115_SUBADDRESS, AS1115_DISPTEST, 0x00);
 186   if (error) return error;
 187
 188   return error;
 189 }
 190
 191 /**************************************************************************/
 192 /*!
 193     @brief  Sets the decode enable register to indicate if BCD or HEX
 194             decoding should be used.  Set to 0 for no BCD on all digits.
 195 */
 196 /**************************************************************************/
 197 as1115Error_t as1115SetDecodeMode(uint8_t x)
 198 {
 199   as1115Error_t error = AS1115_ERROR_OK;
 200
 201   error = as1115WriteCmdData(AS1115_SUBADDRESS, AS1115_DECODEMODE, x);
 202   return error;
 203 }
 204
 205 /**************************************************************************/
 206 /*!
 207     @brief  Sets the intensity control register (0..15 or 0x00..0x0F)
 208 */
 209 /**************************************************************************/
 210 as1115Error_t as1115SetBrightness(uint8_t x)
 211 {
 212   as1115Error_t error = AS1115_ERROR_OK;
 213
 214   if (x > 0xF) x = 0xF;
 215
 216   error = as1115WriteCmdData(AS1115_SUBADDRESS, AS1115_INTENSITY, x);
 217   return error;
 218 }
 219
 220 /**************************************************************************/
 221 /*!
 222     @brief  Sets the feature bit (controls blinking, clock source, etc.)
 223 */
 224 /**************************************************************************/
 225 as1115Error_t as1115SetFeature(uint8_t feature)
 226 {
 227   as1115Error_t error = AS1115_ERROR_OK;
 228
 229   error = as1115WriteCmdData(AS1115_SUBADDRESS, AS1115_FEATURE, feature);
 230   return error;
 231 }
 232
 233 /**************************************************************************/
 234 /*!
 235     @brief  Writes an 8-bit buffer to the display
 236 */
 237 /**************************************************************************/
 238 as1115Error_t as1115WriteBuffer(uint8_t *buffer)
 239 {
 240   as1115Error_t error = AS1115_ERROR_OK;
 241   uint32_t i;
 242
 243   if (!_as1115Initialised) as1115Init();
 244
 245   // Clear write buffers
 246   for ( i = 0; i < I2C_BUFSIZE; i++ )
 247   {
 248     I2CMasterBuffer[i] = 0x00;
 249   }
 250
 251   // Update individual digits
 252   for ( i = 0; i < 8; i++ )
 253   {
 254     I2CWriteLength = 3;
 255     I2CReadLength = 0;
 256     I2CMasterBuffer[0] = AS1115_SUBADDRESS; // I2C device address
 257     I2CMasterBuffer[1] = i+1;               // Digit register
 258     I2CMasterBuffer[2] = buffer[i];         // Value
 259     i2cEngine();
 260   }
 261
 262   return AS1115_ERROR_OK;
 263 }
 264