Building a button to trigger a message on rak 4630

I was wondering if I could wire this button to send a message over helium/ttn? For example if when I press this button it would trigger the word “next” to be sent over the Helium network. Where would I need to solder the connections to? It has 4 pins on it, and what code example would be best to create something like this


You should. You can connect it to IO1 and IO2.

Check this code, you can connect the button pins on IO1 and GND for this to work. You have to update the regions and keys/eui.

#include <Arduino.h>
#include <LoRaWan-RAK4630.h> //http://librarymanager/All#SX126x
#include <SPI.h>

// RAK4630 supply two LED
#ifndef LED_BUILTIN
#define LED_BUILTIN 35
#endif

#ifndef LED_BUILTIN2
#define LED_BUILTIN2 36
#endif

bool doOTAA = true;   // OTAA is used by default.
#define SCHED_MAX_EVENT_DATA_SIZE APP_TIMER_SCHED_EVENT_DATA_SIZE /**< Maximum size of scheduler events. */
#define SCHED_QUEUE_SIZE 60										  /**< Maximum number of events in the scheduler queue. */
#define LORAWAN_DATERATE DR_0									  /*LoRaMac datarates definition, from DR_0 to DR_5*/
#define LORAWAN_TX_POWER TX_POWER_5							/*LoRaMac tx power definition, from TX_POWER_0 to TX_POWER_15*/
#define JOINREQ_NBTRIALS 3										  /**< Number of trials for the join request. */
DeviceClass_t g_CurrentClass = CLASS_A;					/* class definition*/
LoRaMacRegion_t g_CurrentRegion = LORAMAC_REGION_US915;    /* Region:EU868*/
lmh_confirm g_CurrentConfirm = LMH_CONFIRMED_MSG;				  /* confirm/unconfirm packet definition*/
uint8_t gAppPort = LORAWAN_APP_PORT;							        /* data port*/

/**@brief Structure containing LoRaWan parameters, needed for lmh_init()
*/
static lmh_param_t g_lora_param_init = {LORAWAN_ADR_ON, LORAWAN_DATERATE, LORAWAN_PUBLIC_NETWORK, JOINREQ_NBTRIALS, LORAWAN_TX_POWER, LORAWAN_DUTYCYCLE_OFF};

// Foward declaration
static void lorawan_has_joined_handler(void);
static void lorawan_join_failed_handler(void);
static void lorawan_rx_handler(lmh_app_data_t *app_data);
static void lorawan_confirm_class_handler(DeviceClass_t Class);
static void send_lora_frame(void);

/**@brief Structure containing LoRaWan callback functions, needed for lmh_init()
*/
static lmh_callback_t g_lora_callbacks = {BoardGetBatteryLevel, BoardGetUniqueId, BoardGetRandomSeed,
                                        lorawan_rx_handler, lorawan_has_joined_handler, lorawan_confirm_class_handler, lorawan_join_failed_handler
                                       };
//OTAA keys !!!! KEYS ARE MSB !!!!
uint8_t nodeDeviceEUI[8] = {0x70, 0xB3, 0xD5, 0x7E, 0xD0, 0x04, 0xB0, 0x65};
uint8_t nodeAppEUI[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
uint8_t nodeAppKey[16] = {0x8A, 0x02, 0x95, 0x2C, 0xFD, 0x98, 0x3A, 0x7F, 0x39, 0x2D, 0x75, 0x9A, 0x5A, 0x02, 0xD4, 0x86};

// ABP keys
uint32_t nodeDevAddr = 0x260116F8;
uint8_t nodeNwsKey[16] = {0x7E, 0xAC, 0xE2, 0x55, 0xB8, 0xA5, 0xE2, 0x69, 0x91, 0x51, 0x96, 0x06, 0x47, 0x56, 0x9D, 0x23};
uint8_t nodeAppsKey[16] = {0xFB, 0xAC, 0xB6, 0x47, 0xF3, 0x58, 0x45, 0xC7, 0x50, 0x7D, 0xBF, 0x16, 0x8B, 0xA8, 0xC1, 0x7C};

// Private defination
#define LORAWAN_APP_DATA_BUFF_SIZE 64                     /**< buffer size of the data to be transmitted. */
static uint8_t m_lora_app_data_buffer[LORAWAN_APP_DATA_BUFF_SIZE];            //< Lora user application data buffer.
static lmh_app_data_t m_lora_app_data = {m_lora_app_data_buffer, 0, 0, 0, 0}; //< Lora user application data structure.

static uint32_t count = 0;
static uint32_t count_fail = 0;

void setup()
{
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, LOW);
  pinMode(WB_IO1,INPUT_PULLUP);

  // Initialize LoRa chip.
  lora_rak4630_init();

  // Initialize Serial for debug output
  time_t timeout = millis();
  Serial.begin(115200);
  while (!Serial)
  {
    if ((millis() - timeout) < 5000)
    {
      delay(100);
    }
    else
    {
      break;
    }
  }
  Serial.println("=====================================");
  Serial.println("Welcome to RAK4630 LoRaWan!!!");
  if (doOTAA)
  {
    Serial.println("Type: OTAA");
  }
  else
  {
    Serial.println("Type: ABP");
  }

  switch (g_CurrentRegion)
  {
    case LORAMAC_REGION_AS923:
      Serial.println("Region: AS923");
      break;
    case LORAMAC_REGION_AU915:
      Serial.println("Region: AU915");
      break;
    case LORAMAC_REGION_CN470:
      Serial.println("Region: CN470");
      break;
    case LORAMAC_REGION_EU433:
      Serial.println("Region: EU433");
      break;
    case LORAMAC_REGION_IN865:
      Serial.println("Region: IN865");
      break;
    case LORAMAC_REGION_EU868:
      Serial.println("Region: EU868");
      break;
    case LORAMAC_REGION_KR920:
      Serial.println("Region: KR920");
      break;
    case LORAMAC_REGION_US915:
      Serial.println("Region: US915");
      break;
  }
  Serial.println("=====================================");
  
  // Setup the EUIs and Keys
  if (doOTAA)
  {
    lmh_setDevEui(nodeDeviceEUI);
    lmh_setAppEui(nodeAppEUI);
    lmh_setAppKey(nodeAppKey);
  }
  else
  {
    lmh_setNwkSKey(nodeNwsKey);
    lmh_setAppSKey(nodeAppsKey);
    lmh_setDevAddr(nodeDevAddr);
  }

  uint32_t err_code;
  // Initialize LoRaWan
  err_code = lmh_init(&g_lora_callbacks, g_lora_param_init, doOTAA, g_CurrentClass, g_CurrentRegion);
  if (err_code != 0)
  {
    Serial.printf("lmh_init failed - %d\n", err_code);
    return;
  }

  // Start Join procedure
  lmh_join();
}

void loop()
{
  // Put your application tasks here, like reading of sensors,
  // Controlling actuators and/or other functions. 
  int stat=digitalRead(WB_IO1);
  if(!stat){
    send_lora_frame();
    delay(5000);
  }
}

/**@brief LoRa function for handling HasJoined event.
 */
void lorawan_has_joined_handler(void)
{
  Serial.println("OTAA Mode, Network Joined!");
}

/**@brief LoRa function for handling OTAA join failed
*/
static void lorawan_join_failed_handler(void)
{
  Serial.println("OTAA join failed!");
  Serial.println("Check your EUI's and Keys's!");
  Serial.println("Check if a Gateway is in range!");
}
/**@brief Function for handling LoRaWan received data from Gateway
 *
 * @param[in] app_data  Pointer to rx data
 */
void lorawan_rx_handler(lmh_app_data_t *app_data)
{
  Serial.printf("LoRa Packet received on port %d, size:%d, rssi:%d, snr:%d, data:%s\n",
          app_data->port, app_data->buffsize, app_data->rssi, app_data->snr, app_data->buffer);
}

void lorawan_confirm_class_handler(DeviceClass_t Class)
{
  Serial.printf("switch to class %c done\n", "ABC"[Class]);
  // Informs the server that switch has occurred ASAP
  m_lora_app_data.buffsize = 0;
  m_lora_app_data.port = gAppPort;
  lmh_send(&m_lora_app_data, g_CurrentConfirm);
}

void send_lora_frame(void)
{
  if (lmh_join_status_get() != LMH_SET)
  {
    //Not joined, try again later
    return;
  }

  uint32_t i = 0;
  memset(m_lora_app_data.buffer, 0, LORAWAN_APP_DATA_BUFF_SIZE);
  m_lora_app_data.port = gAppPort;
  m_lora_app_data.buffer[i++] = 1;
  m_lora_app_data.buffsize = i;

  lmh_error_status error = lmh_send(&m_lora_app_data, g_CurrentConfirm);
  if (error == LMH_SUCCESS)
  {
    count++;
    Serial.printf("lmh_send ok count %d\n", count);
  }
  else
  {
    count_fail++;
    Serial.printf("lmh_send fail count %d\n", count_fail);
  }
}

So there are 4 pins on the button, do I only wire it to 2 of the pins on the button and leave the other 2 untouched? Ok, I will look into this

You should check which pins are open by default and shorted when pressed down.

Most likely that will be like this illustration created by one of my colleagues.

image

1 Like

I successfully setup the button concept! Now, I would like for it to send a message. Couple of questions here

  1. How would I setup the button press to trigger a message such as “next”
  2. What does the payload decoder for sending texts over the network look like?
  1. Checkout the LoRaWAN_OTAA_ABP example in your Arduino IDE. It is sending a plain Hello! text.

image

  1. I am not really experienced Javascript coder but JS almost share syntax on C. You can find many decoders discussion for TTN or Chirpstack by simply using google :wink:
function Decoder(bytes, port) {
  // Decode plain text; for testing only 
  return {
      myTestValue: String.fromCharCode.apply(null, bytes)
  };
}