MPC4451 I2C support

Marlin/src/HAL/HAL_LPC1768/include/Wire.h

@@ -0,0 +1,58 @@
+/*
+  TwoWire.h - TWI/I2C library for Arduino & Wiring
+  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+  Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
+*/
+
+// Modified for use with the mcp4451 digipot routine
+
+#if defined(TARGET_LPC1768)
+
+#ifndef TwoWire_h
+#define TwoWire_h
+
+#include <inttypes.h>
+
+class TwoWire
+{
+
+  public:
+//    TwoWire();
+    void begin();
+    void beginTransmission(uint8_t);
+    uint8_t endTransmission(void);
+    size_t write(uint8_t);
+};
+
+//extern TwoWire Wire;//
+
+TwoWire Wire;
+
+  ////////////////////////////////////////////////////////////////////////////////////////
+  extern "C" uint8_t digipot_mcp4451_start(uint8_t sla);
+  extern "C" void digipot_mcp4451_init(void);
+  extern "C" uint8_t digipot_mcp4451_send_byte(uint8_t data);
+
+
+  void TwoWire::beginTransmission(uint8_t sla) { digipot_mcp4451_start(sla);}
+  void TwoWire::begin(void) {digipot_mcp4451_init();}
+  size_t TwoWire::write(uint8_t data) {return digipot_mcp4451_send_byte(data);}
+  uint8_t TwoWire::endTransmission(void) {return 1;}
+
+#endif
+#endif  // TARGET_LPC1768

Marlin/src/HAL/HAL_LPC1768/include/digipot_mcp4451_I2C_routines.c

@@ -0,0 +1,171 @@
+/**
+  * Marlin 3D Printer Firmware
+  * Copyright (C) 2016, 2017 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+  *
+  * Based on Sprinter and grbl.
+  * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+  *
+  * This program is free software: you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation, either version 3 of the License, or
+  * (at your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+  *
+*/
+
+// adapted from  I2C/master/master.c example
+//   https://www-users.cs.york.ac.uk/~pcc/MCP/HAPR-Course-web/CMSIS/examples/html/master_8c_source.html
+
+
+
+#if defined(TARGET_LPC1768)
+
+  #ifdef __cplusplus
+    extern "C" {
+  #endif
+
+  #include <lpc17xx_i2c.h>
+  #include <lpc17xx_pinsel.h>
+  #include <lpc17xx_libcfg_default.h>
+
+  //////////////////////////////////////////////////////////////////////////////////////
+
+  // These two routines are exact copies of the lpc17xx_i2c.c routines.  Couldn't link to
+  // to the lpc17xx_i2c.c routines so had to copy them into this file & rename them.
+
+  static uint32_t _I2C_Start (LPC_I2C_TypeDef *I2Cx)
+  {
+    // Reset STA, STO, SI
+    I2Cx->I2CONCLR = I2C_I2CONCLR_SIC|I2C_I2CONCLR_STOC|I2C_I2CONCLR_STAC;
+
+    // Enter to Master Transmitter mode
+    I2Cx->I2CONSET = I2C_I2CONSET_STA;
+
+    // Wait for complete
+    while (!(I2Cx->I2CONSET & I2C_I2CONSET_SI));
+    I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
+    return (I2Cx->I2STAT & I2C_STAT_CODE_BITMASK);
+  }
+
+  static void _I2C_Stop (LPC_I2C_TypeDef *I2Cx)
+  {
+
+    /* Make sure start bit is not active */
+    if (I2Cx->I2CONSET & I2C_I2CONSET_STA)
+    {
+      I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
+    }
+
+    I2Cx->I2CONSET = I2C_I2CONSET_STO|I2C_I2CONSET_AA;
+
+    I2Cx->I2CONCLR = I2C_I2CONCLR_SIC;
+  }
+
+
+  //////////////////////////////////////////////////////////////////////////////////////
+
+
+  #define USEDI2CDEV_M  1  // use I2C1 controller
+
+  #if (USEDI2CDEV_M == 0)
+    #define I2CDEV_M LPC_I2C0
+  #elif (USEDI2CDEV_M == 1)
+    #define I2CDEV_M LPC_I2C1
+  #elif (USEDI2CDEV_M == 2)
+    #define I2CDEV_M LPC_I2C2
+  #else
+    #error "Master I2C device not defined!"
+  #endif
+
+
+  PINSEL_CFG_Type PinCfg;
+  I2C_M_SETUP_Type transferMCfg;
+
+  #define I2C_status (LPC_I2C1->I2STAT & I2C_STAT_CODE_BITMASK)
+
+
+  uint8_t digipot_mcp4451_start(uint8_t sla) {  // send slave address and write bit
+    // Sometimes TX data ACK or NAK status is returned.  That mean the start state didn't
+    // happen which means only the value of the slave address was send.  Keep looping until
+    // the slave address and write bit are actually sent.
+    do{
+      _I2C_Stop(I2CDEV_M); // output stop state on I2C bus
+      _I2C_Start(I2CDEV_M); // output start state on I2C bus
+      while ((I2C_status != I2C_I2STAT_M_TX_START)
+          && (I2C_status != I2C_I2STAT_M_TX_RESTART)
+          && (I2C_status != I2C_I2STAT_M_TX_DAT_ACK)
+          && (I2C_status != I2C_I2STAT_M_TX_DAT_NACK));  //wait for start to be asserted
+
+      LPC_I2C1->I2CONCLR = I2C_I2CONCLR_STAC; // clear start state before tansmitting slave address
+      LPC_I2C1->I2DAT = (sla <<1) & I2C_I2DAT_BITMASK; // transmit slave address & write bit
+      LPC_I2C1->I2CONSET = I2C_I2CONSET_AA;
+      LPC_I2C1->I2CONCLR = I2C_I2CONCLR_SIC;
+      while ((I2C_status != I2C_I2STAT_M_TX_SLAW_ACK)
+          && (I2C_status != I2C_I2STAT_M_TX_SLAW_NACK)
+          && (I2C_status != I2C_I2STAT_M_TX_DAT_ACK)
+          && (I2C_status != I2C_I2STAT_M_TX_DAT_NACK));  //wait for slaw to finish
+    }while ( (I2C_status == I2C_I2STAT_M_TX_DAT_ACK) ||  (I2C_status == I2C_I2STAT_M_TX_DAT_NACK));
+    return 1;
+  }
+
+
+  void digipot_mcp4451_init(void) {
+
+    /*
+      * Init I2C pin connect
+    */
+    PinCfg.OpenDrain = 0;
+    PinCfg.Pinmode = 0;
+    #if ((USEDI2CDEV_M == 0))
+      PinCfg.Funcnum = 1;
+      PinCfg.Pinnum = 27;
+      PinCfg.Portnum = 0;
+      PINSEL_ConfigPin(&PinCfg); // SDA0 / D57  AUX-1
+      PinCfg.Pinnum = 28;
+      PINSEL_ConfigPin(&PinCfg); // SCL0 / D58  AUX-1
+    #endif
+    #if ((USEDI2CDEV_M == 1))
+      PinCfg.Funcnum = 3;
+      PinCfg.Pinnum = 0;
+      PinCfg.Portnum = 0;
+      PINSEL_ConfigPin(&PinCfg);  // SDA1 / D20 SCA
+      PinCfg.Pinnum = 1;
+      PINSEL_ConfigPin(&PinCfg);  // SCL1 / D21 SCL
+    #endif
+    #if ((USEDI2CDEV_M == 2))
+      PinCfg.Funcnum = 2;
+      PinCfg.Pinnum = 10;
+      PinCfg.Portnum = 0;
+      PINSEL_ConfigPin(&PinCfg); // SDA2 / D38  X_ENABLE_PIN
+      PinCfg.Pinnum = 11;
+      PINSEL_ConfigPin(&PinCfg); // SCL2 / D55  X_DIR_PIN
+    #endif
+    // Initialize I2C peripheral
+    I2C_Init(I2CDEV_M, 400000);  // hardwired to 400KHz bit rate, 100KHz is the other option
+
+    /* Enable Master I2C operation */
+    I2C_Cmd(I2CDEV_M, I2C_MASTER_MODE, ENABLE);
+  }
+
+
+  uint8_t digipot_mcp4451_send_byte(uint8_t data) {
+
+    LPC_I2C1->I2DAT = data & I2C_I2DAT_BITMASK; // transmit data
+    LPC_I2C1->I2CONSET = I2C_I2CONSET_AA;
+    LPC_I2C1->I2CONCLR = I2C_I2CONCLR_SIC;
+    while ((I2C_status != I2C_I2STAT_M_TX_DAT_ACK) && (I2C_status != I2C_I2STAT_M_TX_DAT_NACK));  // wait for xmit to finish
+    return 1;
+  }
+
+
+  #ifdef __cplusplus
+    }
+  #endif
+#endif

Marlin/src/HAL/utility/twi.h

@@ -0,0 +1,4 @@
+// Modified for use with the mcp4451 digipot routine
+#if defined(TARGET_LPC1768)
+
+#endif

Marlin/src/module/stepper.h

@@ -297,7 +297,7 @@ class Stepper {
 
       #ifdef CPU_32_BIT
         // In case of high-performance processor, it is able to calculate in real-time
-        constexpr uint32_t MIN_TIME_PER_STEP = (HAL_STEPPER_TIMER_RATE) / ((STEP_DOUBLER_FREQUENCY) * 2);
+        const uint32_t MIN_TIME_PER_STEP = (HAL_STEPPER_TIMER_RATE) / ((STEP_DOUBLER_FREQUENCY) * 2);
         timer = uint32_t(HAL_STEPPER_TIMER_RATE) / step_rate;
         NOLESS(timer, MIN_TIME_PER_STEP); // (STEP_DOUBLER_FREQUENCY * 2 kHz - this should never happen)
       #else