{"id":571,"date":"2018-09-14T11:23:10","date_gmt":"2018-09-14T11:23:10","guid":{"rendered":"http:\/\/lora.vsb.cz\/?page_id=571"},"modified":"2018-09-17T09:33:12","modified_gmt":"2018-09-17T09:33:12","slug":"build-sensor-with-adafruit-feather-32u4","status":"publish","type":"page","link":"https:\/\/lora.vsb.cz\/index.php\/build-sensor-with-adafruit-feather-32u4\/","title":{"rendered":"Build Sensor with Adafruit Feather 32u4"},"content":{"rendered":"

General Configuration<\/span><\/strong><\/h2>\n

At the Feather 32u4<\/strong>‚s heart is at ATmega32u4 clocked at 8 MHz and at 3.3V logic.\u00a0Feather 32u4 LoRa Radio<\/strong>\u00a0uses the extra space left over to add\u00a0an RFM9x LoRa 868\/915 MHz radio module. We use 868 MHz one. See complete specification here<\/a>.<\/p>\n

    \n
  1. Run Arduino IDE.<\/li>\n
  2. You will need to install the Adafruit Package<\/a> in your Arduino IDE<\/a>. Copy and paste the link below into the Additional Boards Manager URLs option in the Arduino IDE preferences. https:\/\/adafruit.github.io\/arduino-board-index\/package_adafruit_index.json<\/code><\/li>\n
  3. Install the Adafruit boards via Tools -> Boards Manager<\/li>\n
  4. You should see in menu Tools<\/strong> -> Board<\/strong> the Adafruit Feather 32u4
    \n\"\"<\/li>\n
  5. Connect\u00a0 the Adafruit Feather using directly micro USB cable (no FTDI adapter is needed here).<\/li>\n
  6. Check the appropriate COM port which is used for communication with Adafruit.\"\"<\/li>\n<\/ol>\n

    Temperature Sensor using Adafruit Feather 32u4 and DHT22<\/strong>
    \n\"\"
    \n<\/span><\/h2>\n
      \n
    1. Connect the one wire temperature sensor DHT22 to Adafruit. For data, we can use any of available digital<\/strong> pins, see here<\/a><\/li>\n
    2. Use an addition 4.7k resistor between +3.3V and the data line.<\/li>\n
    3. You need to additionally wire up the board’s IO1 pin with the board’s pin 6. You can use a simple wire bridge for that. Check the picture below to make sure you are actually using the right pins.<\/li>\n
    4. Everything assembled:
      \n\"\"<\/li>\n
    5. For communication with DHT22 we need\u00a0Arduino library for DHT11DHT22, etc Temp & Humidity Sensors<\/a>, import it to Arduino IDE<\/li>\n
    6. Check if your Adafruit Feather can simply read the temperature and humidity from a sensor using Arduino IDE simple sketch:\n
      #include <\/span>\"DHT.h\"<\/span>\r\n\r\n#define<\/span> DHTPIN 2 \/\/ define data pin on Adafruit, we used 2\r\n#define<\/span> DHTTYPE DHT22   \/\/ define type of sensor\r\nDHT<\/span> dht(DHTPIN, DHTTYPE); \/\/define properties of sensor\r\n\r\nfloat<\/span> hum;\r\nfloat<\/span> temp;  \r\n                                \r\nvoid<\/span> setup<\/span>()\r\n{\r\n  Serial.begin<\/span>(9600);   \r\n  dht.begin<\/span>(); \/\/initiate the communication with sensor                                \r\n}\r\n\r\nvoid<\/span> loop<\/span>()\r\n{\r\n  hum = dht.readHumidity();  \/\/save the value of humidity to hum variable\r\n  temp = dht.readTemperature<\/span>(); \/\/ save the value of temperature to temp variable             \r\n\r\n  Serial.print<\/span>(\"Humidity is: \"<\/span>);                \r\n  Serial.print<\/span>(hum);\r\n  Serial.print<\/span>(\"% | \"<\/span>);\r\n  Serial.print<\/span>(\"Temperature is: \");\r\n  Serial.print<\/span>(temp);\r\n  Serial.println<\/span>(\" degrees of Celsius\"<\/span>);\r\n\r\n  delay<\/span>(1000);                              \r\n}<\/pre>\n<\/li>\n
    7. \u00a0Use serial monitor,… and it works!\"\"<\/li>\n
    8. Within TheThingsNetwork\u00a0https:\/\/thethingsnetwork.org\/<\/a>\u00a0 we use the LMIC-Library\u00a0\u00a0https:\/\/github.com\/matthijskooijman\/arduino-lmic<\/a>,\u00a0slightly modified to run in the Arduino environment, allowing using the SX1272, SX1276 tranceivers and compatible modules (such as some HopeRF RFM9x modules).<\/li>\n
    9. Import following library into ArduinoIDE:\u00a0https:\/\/github.com\/matthijskooijman\/arduino-lmic<\/a><\/li>\n
    10. Before a device can communicate via The Things Network<\/a> you need to register it with an application. To use the default Over The Air Activation (OTAA) you will need to register your device with its Device EUI<\/a>.<\/li>\n
    11. We used\u00a0adafruit-feather-32u4-lora-ota.ino<\/a>\u00a0sketch with slight modification.<\/li>\n
    12. Change the\u00a0DEVEUI<\/strong>, APPEUI<\/strong> and APPKEY.
      \n<\/strong>Note:<\/span>\u00a0DEVEUI<\/strong>, APPEUI\u00a0<\/strong>are reverse order (LSB)<\/li>\n
    13. Change pin mapping to:\n
      const lmic_pinmap lmic_pins = { \r\n   .nss = 8, \r\n   .rxtx = LMIC_UNUSED_PIN, \r\n   .rst = 4, \r\n   .dio = {7, 6, LMIC_UNUSED_PIN}, \r\n};<\/pre>\n<\/li>\n
    14. To send current temperature via TTN comment following:\n
      \/\/static mydata[] = \"Hello, TTN over OTAA!\";<\/pre>\n<\/li>\n
    15. Don’t forget to add:
      \n#include \"DHT.h\"<\/code><\/li>\n
    16. Add to\u00a0void do_send(osjob_t* j)<\/code>\u00a0the following:\n
      float teplota = dht.readTemperature();\r\ndtostrf(teplota,5,2,(char*)mydata);   \r\nLMIC_setTxData2(1, mydata, strlen((char*) mydata), 0); \r\nSerial.println(F(\"Packet queued\"));<\/pre>\n<\/li>\n
    17. Let LMIC compensate for an inaccurate clock. Just add this to your setup somewhere:\n
      LMIC_setClockError(MAX_CLOCK_ERROR * 1 \/ 100);\u00a0\/\/ Let LMIC compensate for +\/- 1% clock error<\/pre>\n
      This lets LMIC make the RX windows longer and start sooner so it will catch a downlink even when the clock runs up to 1% faster or slower.<\/li>\n
    18. Check TTN console if payload as temperature is received:
      \n\"\"<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"
      General Configuration At the Feather 32u4‚s heart is at ATmega32u4 clocked at 8 MHz and at 3.3V logic.\u00a0Feather 32u4 LoRa Radio\u00a0uses the extra space left over to add\u00a0an RFM9x LoRa 868\/915 MHz radio module. We use 868 MHz one. See complete specification here. Run Arduino IDE. You will need to install the Adafruit Package in […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-571","page","type-page","status-publish","hentry","post"],"_links":{"self":[{"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/pages\/571","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/comments?post=571"}],"version-history":[{"count":6,"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/pages\/571\/revisions"}],"predecessor-version":[{"id":586,"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/pages\/571\/revisions\/586"}],"wp:attachment":[{"href":"https:\/\/lora.vsb.cz\/index.php\/wp-json\/wp\/v2\/media?parent=571"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}