elua · celetts · Dec 18, 2011 · Dec 20, 2011 · Dec 20, 2011
diff --git a/SConstruct b/SConstruct
@@ -352,7 +352,7 @@ if not GetOption( 'help' ):
 
   # Application files
   app_files = """ src/main.c src/romfs.c src/semifs.c src/xmodem.c src/shell.c src/term.c src/common.c src/common_tmr.c src/buf.c src/elua_adc.c src/dlmalloc.c 
-                  src/salloc.c src/luarpc_elua_uart.c src/elua_int.c src/linenoise.c src/common_uart.c src/eluarpc.c """
+                  src/salloc.c src/luarpc_elua_uart.c src/elua_int.c src/linenoise.c src/common_uart.c src/eluarpc.c src/elua_qei.c """
 
   # Newlib related files
   newlib_files = " src/newlib/devman.c src/newlib/stubs.c src/newlib/genstd.c src/newlib/stdtcp.c"
@@ -367,7 +367,7 @@ if not GetOption( 'help' ):
   comp.Append(CPPPATH = ['src/fatfs'])
 
   # Lua module files
-  module_names = "pio.c spi.c tmr.c pd.c uart.c term.c pwm.c lpack.c bit.c net.c cpu.c adc.c can.c luarpc.c bitarray.c elua.c i2c.c"
+  module_names = "pio.c spi.c tmr.c pd.c uart.c term.c pwm.c lpack.c bit.c net.c cpu.c adc.c can.c luarpc.c bitarray.c elua.c i2c.c qei.c"
   module_files = " " + " ".join( [ "src/modules/%s" % name for name in module_names.split() ] )
 
   # Remote file system files

diff --git a/doc/eluadoc/refman_gen_qei.lua b/doc/eluadoc/refman_gen_qei.lua
@@ -0,0 +1,114 @@
+-- eLua reference manual - QEI
+
+data_en = 
+{
+
+  -- Title
+  title = "eLua reference manual - QEI",
+
+  -- Menu name
+  menu_name = "qei",
+
+  -- Overview
+  overview = [[This module contains functions that access the Quadrature Encoder Interface (QEI).<\p>
+  <p>Using the QEI is a three or four step process: First the peripheral must be initiailised (Using $qei.init$). The peripheral can be optionally initialised to measure velocity in a second step (Using $qei.velInit$). The peripheral must then be enabled ($qei.enable$) before lastly, results can be read (Using $qei.getPosition$, and if initialised, $qei.getVelPulses$, $qei.getRPM$). The QEI can also be disabled via $qei.disabled$<\p>
+  <p>Encoders can be set alone or in combination in the initialisation functions, however must have data read in separate calls for each encoder.<\p>
+  <p>This module can be utilized if the device in use has a supported QEI peripheral (see @status.html@status@ for details) and if QEI functionality is enabled at build time (see @building.html@building@).</p>
+<p><span class="warning">IMPORTANT</span>: Platform support varies for this module (see @status.html#plat_notes@status notes@ for details) .
+  ]],
+
+    -- Structures
+    structures =
+    {
+        { 
+            text = [[// eLua qei error codes
+            enum
+            {
+                ELUA_QEI_ERR_OK = 0,                // exported as $qei.ERR_OK$
+                ELUA_QEI_ERR_VEL_NOT_ENABLED,  // exported as $qei.ERR_VELOCITY_NOT_ENABLED$
+                ELUA_QEI_ERR_ENC_NOT_ENABLED,   // exported as $qei.ERR_ENCODER_NOT_ENABLED$
+            };]],
+            name = "Error codes",
+            desc = "These are the error codes defined by the eLua_qei layer and are returned by a number of functions in this module.",
+        }
+    },
+
+  -- Functions
+  funcs = 
+  {
+    { sig = "#qei.init#( encoder_id, phase, swap, index, max_count )",
+      desc = "Initiates the encoder channels for use.",
+      args = 
+      {
+        "$encoder_id$ - QEI channel ID. Specified as qei.CH0, qei.CH1, qei.CHO1. Channels 0 or 1 can be initialised together or separately by calling this function once on each encoder.",
+        "$phase$ - Each encoder has two phases: A and B. Either qei.PHA or qei.PHAB can be specified, effecting resolution. NOTE: phase B cannot be set on its own.",
+        "$swap$ - Specified as either qei.SWAP or qei.NO_SWAP, this defines whether the phases are switched before processing. This changes the direction of the encoders via software.",
+        "$index$ - Specified as either qei.INDEX or qei.NO_INDEX, this defines whether an index pulse is used or not.",
+        "$max_count$ - Sets the maximum count of the encoder before it resets to zero.",
+      }
+    },
+    { sig = "#qei.velInit#( encoder_id, vel_period, ppr, edges )",
+      desc = "Optionally initialises the encoder channels for use in velocity measurement.",
+      args = 
+      {
+        "$encoder_id$ - QEI channel ID. Specified as qei.CH0, qei.CH1, qei.CHO1. Channels 0 or 1 can be initialised together or separately by calling this function once on each encoder.",
+        "$vel_period$ - Sets the period in micro seconds over which time the velocity is calculated.",
+        "$ppr$ - Pulses per revolution of the encoder.",
+        "$edges$ - The number of edges the encoder is triggering on.",
+      }
+    },
+    { sig = "#qei.enable#( encoder_id )",
+      desc = "Enables the encoder, post initialisation.",
+      args = 
+      {
+        "$encoder_id$ - QEI channel ID. Specified as qei.CH0, qei.CH1, qei.CHO1. Channels 0 or 1 can be enabled separately by calling this function once on each encoder.",
+      }
+    },
+    { sig = "#qei.disable#( encoder_id )",
+      desc = "Disables the encoder.",
+      args = 
+      {
+        "$encoder_id$ - QEI channel ID. Specified as qei.CH0, qei.CH1, qei.CHO1. Channels 0 or 1 can be disabled separately by calling this function once on each encoder.",
+      }
+    },
+    { sig = "#qei.getPosition#( encoder_id )",
+      desc = "Returns the current count of the encoder, ranging between 0 and maximum value set during initialisation.",
+      args = 
+      {
+        "$encoder_id$ - QEI channel ID. Ethier qei.CH0 or qei.CH1 can be called. NOTE: qei.CH01 cannot be called. Must call each encoder separately.",
+      }
+      ret = 
+      {
+        "$count$ - the current encoder count between 0 and max_count set during initialisation.",
+        "$err$ - Error code as defined above."
+      }
+    },
+    { sig = "#qei.getVelPulses#( encoder_id )",
+      desc = "Returns the number of pulses counted during the vel_period set during initialisation of velocity measurement. This value can be used raw, but is also used to calculate the RPM. ",
+      args = 
+      {
+        "$encoder_id$ - QEI channel ID. Ethier qei.CH0 or qei.CH1 can be called. NOTE: qei.CH01 cannot be called. Must call each encoder separately.",
+      }
      ret = 
+      {
+        "$pulses$ - The number of pulses recorded during the period defined during initialisation.",
+        "$err$ - Error code as defined above."
+      }
+    },
+    { sig = "#qei.getRPM#( encoder_id )",
+      desc = "Returns the current number of revolutions per minute (RPM) of the selected encoder.",
+      args = 
+      {
+        "$encoder_id$ - QEI channel ID. Ethier qei.CH0 or qei.CH1 can be called. NOTE: qei.CH01 cannot be called. Must call each encoder separately.",
+      }
+      ret = 
+      {
+        "$rpm$ - The current rpm.",
+        "$err$ - Error code as defined above."
+      }
+    }
+  }
+}
+
+data_pt = data_en
+
diff --git a/inc/elua_qei.h b/inc/elua_qei.h
@@ -0,0 +1,41 @@
+//  Quadrature Encoding Interface (QEI)
+
+#ifndef ELUA_QEI_H
+#define ELUA_QEI_H
+
+#include "platform_conf.h"
+
+/* Encoder 0 and 1 each with phase A and B */
+enum valid_encoder_ids { ELUA_QEI_CH0 = 1, ELUA_QEI_CH1, ELUA_QEI_CH01 };
+enum valid_encoder_phases { ELUA_QEI_PHA = 0, ELUA_QEI_PHAB };
+/* Defines whether phases are switched before processing */
+enum qei_swap_codes { ELUA_QEI_NO_SWAP = 0, ELUA_QEI_SWAP };
+/* Defines whether an index pulse is used */
+enum qei_index_codes { ELUA_QEI_NO_INDEX = 0, ELUA_QEI_INDEX };
+/* Error Codes */
+enum qei_error_codes { ELUA_QEI_ERR_OK = 0, ELUA_QEI_ERR_VEL_NOT_ENABLED, ELUA_QEI_ERR_ENC_NOT_ENABLED };
+
+/* qei_flag keeps track of encoders/channels that are enabled, as well 
+ * as whether they are enabled for velocity measurement.
+ * BIT0 Channel0 Enabled
+ * BIT1 Channel1 Enabled
+ * BIT2 Channel0 Velocity Enabled
+ * BIT3 Channel1 Velocity Enabled
+ * BIT4-7 Unused. */
+u8 qei_flag;
+#define VEL_FLAG_OFFSET 2
+
+/* vel_period is time (us) over which to measure velocity. vel_ticks is
+ * this period converted into counts on the system clock. */
+u32 vel_ticks;
+
+/* Function Prototypes */
+void elua_qei_init( u8 enc_id, u8 phase, u8 swap, u8 index, u32 max_count );
+void elua_qei_vel_init( u8 enc_id, u32 vel_period, int ppr, int edges );
+void elua_qei_enable( u8 enc_id );
+void elua_qei_disable( u8 enc_id );
+u32 elua_qei_getPulses( u8 enc_id );
+s32 elua_qei_getRPM( u8 enc_id );
+u32 elua_qei_getPosition( u8 enc_id );
+
+#endif
diff --git a/inc/platform.h b/inc/platform.h
@@ -315,7 +315,17 @@ u32 platform_eth_get_elapsed_time();
 void platform_usb_cdc_send( u8 data );
 int platform_usb_cdc_recv( s32 timeout );
 
-
+//******************************************************************************
+// Quadrature encoder platform interface
+
+void platform_qei_init( u8 enc_id, u8 phase, u8 swap, u8 index, u32 max_count );
+void platform_qei_vel_init( u8 enc_id, u32 vel_period );
+void platform_qei_enable( u8 enc_id );
+void platform_qei_disable( u8 enc_id );
+u32 platform_qei_get_sys_clk();
+u32 platform_qei_getPulses( u8 enc_id );
+u32 platform_qei_getPosition( u8 enc_id );
+long platform_qei_getDirection( u8 enc_id );
 
 // *****************************************************************************
 // Allocator support

diff --git a/src/elua_qei.c b/src/elua_qei.c
@@ -0,0 +1,51 @@
+//  Quadrature Encoding Interface (QEI)
+
+#include "elua_qei.h"
+#include "platform.h"
+
+#ifdef BUILD_QEI
+static u32 vel_modifier = 0;
+
+void elua_qei_init( u8 enc_id, u8 phase, u8 swap, u8 index, u32 max_count )
+{
+    platform_qei_init( enc_id, phase, swap, index, max_count );
+}
+
+void elua_qei_vel_init( u8 enc_id, u32 vel_period, int ppr, int edges )
+{
+    platform_qei_vel_init( enc_id, vel_period );
+    qei_flag |= ( enc_id << VEL_FLAG_OFFSET );  //Sets encoder velocity flag
+    u32 clk_freq = platform_qei_get_sys_clk();
+    vel_modifier = (clk_freq * 60) / (vel_ticks * ppr * edges);
+}
+void elua_qei_enable( u8 enc_id )
+{
+    platform_qei_enable( enc_id );
+    qei_flag |= enc_id;
+}
+
+void elua_qei_disable( u8 enc_id )
+{
+    platform_qei_disable( enc_id );
+    qei_flag &= ~enc_id;
+}
+
+u32 elua_qei_getPulses( u8 enc_id )
+{
+    u32 pulses = platform_qei_getPulses( enc_id );
+    return pulses;
+}
+
+s32 elua_qei_getRPM( u8 enc_id )
+{
+    u32 pulses = elua_qei_getPulses( enc_id );
+    s32 rpm = pulses * vel_modifier * platform_qei_getDirection( enc_id );
+    return rpm;
+}
+
+u32 elua_qei_getPosition( u8 enc_id )
+{
+    return platform_qei_getPosition( enc_id );
+}
+
+#endif
diff --git a/src/modules/auxmods.h b/src/modules/auxmods.h
@@ -57,6 +57,9 @@ LUALIB_API int ( luaopen_elua )( lua_State *L );
 #define AUXLIB_I2C  "i2c"
 LUALIB_API int ( luaopen_i2c )( lua_State *L );
 
+#define AUXLIB_QEI      "qei"
+LUALIB_API int ( luaopen_qei )( lua_State *L );
+
 // Helper macros
 #define MOD_CHECK_ID( mod, id )\
   if( !platform_ ## mod ## _exists( id ) )\