boards/esp32/heltec_wifi_lora32: Add support to SX1276

This commit adds support to SX1276 transceiver on Heltec WiFi LoRa32
board.

Signed-off-by: Alan C. Assis <acassis@gmail.com>

boards/xtensa/esp32/heltec_wifi_lora32/configs/sx1276/defconfig

@@ -0,0 +1,68 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+# CONFIG_ARCH_LEDS is not set
+# CONFIG_LPWAN_SX127X_LORA is not set
+# CONFIG_NSH_ARGCAT is not set
+# CONFIG_NSH_CMDOPT_HEXDUMP is not set
+CONFIG_ARCH="xtensa"
+CONFIG_ARCH_BOARD="heltec_wifi_lora32"
+CONFIG_ARCH_BOARD_COMMON=y
+CONFIG_ARCH_BOARD_HELTEC_WIFI_LORA32=y
+CONFIG_ARCH_CHIP="esp32"
+CONFIG_ARCH_CHIP_ESP32=y
+CONFIG_ARCH_CHIP_ESP32WROVER=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_ARCH_XTENSA=y
+CONFIG_BOARD_LOOPSPERMSEC=16717
+CONFIG_BUILTIN=y
+CONFIG_DEBUG_FEATURES=y
+CONFIG_DEBUG_LIB=y
+CONFIG_DRIVERS_LPWAN=y
+CONFIG_DRIVERS_WIRELESS=y
+CONFIG_ESP32_IGNORE_CHIP_REVISION_CHECK=y
+CONFIG_ESP32_SPI2=y
+CONFIG_ESP32_SPI2_CLKPIN=5
+CONFIG_ESP32_SPI2_CSPIN=18
+CONFIG_ESP32_SPI2_MISOPIN=19
+CONFIG_ESP32_SPI2_MOSIPIN=27
+CONFIG_ESP32_UART0=y
+CONFIG_EXAMPLES_SX127X=y
+CONFIG_EXAMPLES_SX127X_RFFREQ=915000000
+CONFIG_EXAMPLES_SX127X_TXDATA=63
+CONFIG_EXAMPLES_SX127X_TXPOWER=20
+CONFIG_FS_PROCFS=y
+CONFIG_HAVE_CXX=y
+CONFIG_HAVE_CXXINITIALIZE=y
+CONFIG_IDLETHREAD_STACKSIZE=3072
+CONFIG_INIT_ENTRYPOINT="nsh_main"
+CONFIG_INIT_STACKSIZE=3072
+CONFIG_INTELHEX_BINARY=y
+CONFIG_LINE_MAX=64
+CONFIG_LPWAN_SX127X=y
+CONFIG_LPWAN_SX127X_FSKOOK=y
+CONFIG_LPWAN_SX127X_RFFREQ_DEFAULT=915000000
+CONFIG_LPWAN_SX127X_RXSUPPORT=y
+CONFIG_LPWAN_SX127X_TXPOWER_DEFAULT=20
+CONFIG_LPWAN_SX127X_TXSUPPORT=y
+CONFIG_MM_REGIONS=3
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_FILEIOSIZE=512
+CONFIG_NSH_READLINE=y
+CONFIG_PREALLOC_TIMERS=4
+CONFIG_RAM_SIZE=114688
+CONFIG_RAM_START=0x20000000
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_HPWORK=y
+CONFIG_SCHED_WAITPID=y
+CONFIG_START_DAY=6
+CONFIG_START_MONTH=12
+CONFIG_START_YEAR=2011
+CONFIG_SYSLOG_BUFFER=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_UART0_SERIAL_CONSOLE=y

boards/xtensa/esp32/heltec_wifi_lora32/src/Make.defs

@@ -26,6 +26,10 @@ ifeq ($(CONFIG_BOARDCTL),y)
 CSRCS += esp32_appinit.c
 endif
 
+ifeq ($(CONFIG_LPWAN_SX127X),y)
+CSRCS += esp32_sx127x.c
+endif
+
 DEPPATH += --dep-path board
 VPATH += :board
 CFLAGS += ${INCDIR_PREFIX}$(TOPDIR)$(DELIM)arch$(DELIM)$(CONFIG_ARCH)$(DELIM)src$(DELIM)board$(DELIM)board

boards/xtensa/esp32/heltec_wifi_lora32/src/esp32_bringup.c

@@ -81,6 +81,16 @@ int esp32_bringup(void)
     }
 #endif
 
+#ifdef CONFIG_LPWAN_SX127X
+  ret = esp32_lpwaninitialize();
+  if (ret < 0)
+    {
+      syslog(LOG_ERR,
+             "ERROR: Failed to initialize wireless driver: %d\n",
+             ret);
+    }
+#endif /* CONFIG_LPWAN_SX127X */
+
   /* If we got here then perhaps not all initialization was successful, but
    * at least enough succeeded to bring-up NSH with perhaps reduced
    * capabilities.

boards/xtensa/esp32/heltec_wifi_lora32/src/esp32_sx127x.c

@@ -0,0 +1,229 @@
+/****************************************************************************
+ * boards/xtensa/esp32/heltec_wifi_lora32/src/esp32_sx127x.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdio.h>
+#include <stdint.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/board.h>
+#include <nuttx/signal.h>
+#include <nuttx/wireless/lpwan/sx127x.h>
+#include <arch/board/board.h>
+
+#include "esp32_gpio.h"
+#include "esp32_spi.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+#include "heltec_wifi_lora32.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* SX127X on SPI2 bus */
+
+#define SX127X_SPI 2
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static void sx127x_chip_reset(void);
+static int sx127x_opmode_change(int opmode);
+static int sx127x_freq_select(uint32_t freq);
+static int sx127x_pa_select(bool enable);
+static int sx127x_irq0_attach(xcpt_t isr, void *arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+struct sx127x_lower_s lower =
+{
+  .irq0attach    = sx127x_irq0_attach,
+  .reset         = sx127x_chip_reset,
+  .opmode_change = sx127x_opmode_change,
+  .freq_select   = sx127x_freq_select,
+  .pa_select     = sx127x_pa_select,
+  .pa_force      = true
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: sx127x_irq0_attach
+ ****************************************************************************/
+
+static int sx127x_irq0_attach(xcpt_t isr, void *arg)
+{
+  int irq = ESP32_PIN2IRQ(GPIO_SX127X_DIO0);
+  int ret;
+
+  /* Make sure the interrupt is disabled */
+
+  esp32_gpioirqdisable(irq);
+
+  wlinfo("Attach DIO0 IRQ\n");
+
+  /* Attach to IRQ on pin connected to DIO0 */
+
+  ret = irq_attach(irq, isr, arg);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: gpint_attach() failed: %d\n", ret);
+      return ret;
+    }
+
+  /* IRQ on rising edge */
+
+  esp32_gpioirqenable(irq, RISING);
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: sx127x_chip_reset
+ ****************************************************************************/
+
+static void sx127x_chip_reset(void)
+{
+  wlinfo("SX127X RESET\n");
+
+  /* Configure reset as output */
+
+  esp32_gpio_matrix_out(GPIO_SX127X_RESET, SIG_GPIO_OUT_IDX, 0, 0);
+  esp32_configgpio(GPIO_SX127X_RESET, OUTPUT_FUNCTION_3 | INPUT_FUNCTION_3);
+
+  /* Set pin to zero */
+
+  esp32_gpiowrite(GPIO_SX127X_RESET, 0);
+
+  /* Wait 1 ms */
+
+  nxsched_usleep(1000);
+
+  /* Set pin to high */
+
+  esp32_gpiowrite(GPIO_SX127X_RESET, 1);
+
+  /* Wait 10 ms */
+
+  nxsched_usleep(10000);
+}
+
+/****************************************************************************
+ * Name: sx127x_opmode_change
+ ****************************************************************************/
+
+static int sx127x_opmode_change(int opmode)
+{
+  /* Do nothing */
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: sx127x_freq_select
+ ****************************************************************************/
+
+static int sx127x_freq_select(uint32_t freq)
+{
+  int ret = OK;
+
+  /* NOTE: this depends on your module version */
+
+  if (freq > SX127X_HFBAND_THR)
+    {
+      ret = -EINVAL;
+      wlerr("HF band not supported\n");
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: sx127x_pa_select
+ ****************************************************************************/
+
+static int sx127x_pa_select(bool enable)
+{
+  int ret = OK;
+
+  /* Only PA_BOOST output connected to antenna */
+
+  if (enable == false)
+    {
+      ret = -EINVAL;
+      wlerr("Module supports only PA_BOOST pin,"
+            " so PA_SELECT must be enabled!\n");
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int esp32_lpwaninitialize(void)
+{
+  struct spi_dev_s *spidev;
+  int ret = OK;
+
+  wlinfo("Register the sx127x module\n");
+
+  /* Setup DIO0 */
+
+  esp32_configgpio(GPIO_SX127X_DIO0, INPUT_FUNCTION_3 | PULLDOWN);
+
+  /* Init SPI bus */
+
+  spidev = esp32_spibus_initialize(SX127X_SPI);
+  if (!spidev)
+    {
+      wlerr("ERROR: Failed to initialize SPI %d bus\n", SX127X_SPI);
+      ret = -ENODEV;
+      goto errout;
+    }
+
+  /* Initialize SX127X */
+
+  ret = sx127x_register(spidev, &lower);
+  if (ret < 0)
+    {
+      wlerr("ERROR: Failed to register sx127x\n");
+      goto errout;
+    }
+
+errout:
+  return ret;
+}

boards/xtensa/esp32/heltec_wifi_lora32/src/heltec_wifi_lora32.h

@@ -37,6 +37,11 @@
 
 /* Heltec WiFi LoRa32 GPIOs *************************************************/
 
+/* SX1276 pins */
+
+#define GPIO_SX127X_RESET   14    /* RESET connected to IO14 */
+#define GPIO_SX127X_DIO0    26    /* DIO0 connected to IO26  */
+
 /* BOOT Button */
 
 #define BUTTON_BOOT  0
@@ -111,5 +116,24 @@
 
 int esp32_bringup(void);
 
+/****************************************************************************
+ * Name: esp32_lpwaninitialize
+ *
+ * Description:
+ *   Initialize the SX127x driver
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_LPWAN_SX127X
+int esp32_lpwaninitialize(void);
+#endif
+
 #endif /* __ASSEMBLY__ */
 #endif /* __BOARDS_XTENSA_ESP32_HELTEC_WIFI_LORA32_SRC_HELTEC_WIFI_LORA32_H */