# DHT library problem **URL:** \ **Category:** Firmware\ **Created:** [January 27, 2021, 9:57pm UTC](https://community.particle.io/t/dht-library-problem/59210 "2021-01-27T21:57:53Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![majed](https://avatars.discourse-cdn.com/v4/letter/m/71c47a/32.png) [@majed](https://community.particle.io/u/majed)\ **Post date:** [January 27, 2021, 9:57pm UTC](https://community.particle.io/t/dht-library-problem/59210/1 "2021-01-27T21:57:53Z")
I used the example code from DHT library and the following error popped up. ```auto Processing dhttester.ino Checking library DHT... Installing library DHT 1.3.0 to lib/DHT ... Library DHT 1.3.0 installed. make -C ../modules/photon/user-part all make[1]: Entering directory '/firmware/modules/photon/user-part' make -C ../../../user make[2]: Entering directory '/firmware/user' Building cpp file: src/dhttester.cpp Invoking: ARM GCC CPP Compiler mkdir -p ../build/target/user/platform-6-msrc/ arm-none-eabi-gcc -DSTM32_DEVICE -DSTM32F2XX -DPLATFORM_THREADING=1 -DPLATFORM_ID=6 -DPLATFORM_NAME=photon -DPLATFORM_GEN=2 -DUSBD_VID_SPARK=0x2B04 -DUSBD_PID_DFU=0xD006 -DUSBD_PID_CDC=0xC006 -DSPARK_PLATFORM -g3 -gdwarf-2 -Os -mcpu=cortex-m3 -mthumb --specs=nano.specs -DINCLUDE_PLATFORM=1 -DPRODUCT_ID=6 -DPRODUCT_FIRMWARE_VERSION=65535 -DUSE_STDPERIPH_DRIVER -DDFU_BUILD_ENABLE -DSYSTEM_VERSION_STRING=2.0.1 -DRELEASE_BUILD -I./inc -I../wiring/inc -I../system/inc -I../services/inc -I../third_party/nanopb/nanopb -I../communication/inc -I../hal/inc -I../hal/shared -I../hal/src/photon -I../hal/src/stm32f2xx -I../hal/src/stm32 -I../hal/network/util -I../hal/network -I../hal/src/photon/api -I../hal/src/photon/include -I../hal/src/photon/wiced/security/BESL/host/WICED/ -I../hal/src/photon/wiced/security/BESL/include -I../hal/src/photon/wiced/security/BESL -I../hal/src/photon/wiced/security/BESL/crypto -I../hal/src/photon/wiced/WWD/include/ -I../hal/src/photon/wiced/platform/include/ -I../hal/src/photon/wiced/platform/GCC/ -I../hal/src/photon/wiced/security/BESL/supplicant/ -I../hal/src/photon/libraries/crypto -I../hal/src/photon/libraries/daemons/DNS_redirect -I../third_party/miniz/miniz -I../platform/shared/inc -I../platform/MCU/STM32F2xx/STM32_USB_Host_Driver/inc -I../platform/MCU/STM32F2xx/STM32_USB_OTG_Driver/inc -I../platform/MCU/STM32F2xx/STM32_StdPeriph_Driver/inc -I../platform/MCU/STM32F2xx/STM32_USB_Device_Driver/inc -I../platform/MCU/STM32F2xx/SPARK_Firmware_Driver/inc -I../platform/MCU/shared/STM32/inc -I../platform/MCU/STM32F2xx/CMSIS/Include -I../platform/MCU/STM32F2xx/CMSIS/Device/ST/Include -I../dynalib/inc -Isrc -I./libraries -Ilib/DHT/src -I. -MD -MP -MF ../build/target/user/platform-6-msrc/dhttester.o.d -ffunction-sections -fdata-sections -Wall -Wno-switch -Wno-error=deprecated-declarations -fmessage-length=0 -fno-strict-aliasing -DSPARK=1 -DPARTICLE=1 -Wundef -DSTART_DFU_FLASHER_SERIAL_SPEED=14400 -DSTART_YMODEM_FLASHER_SERIAL_SPEED=28800 -DBOOTLOADER_SDK_3_3_0_PARTICLE -DPARTICLE_DCT_COMPATIBILITY -DSPARK_PLATFORM_NET=BCM9WCDUSI09 -fno-builtin-malloc -fno-builtin-free -fno-builtin-realloc -DLOG_INCLUDE_SOURCE_INFO=1 -DPARTICLE_USER_MODULE -DUSER_FIRMWARE_IMAGE_SIZE=0x20000 -DUSER_FIRMWARE_IMAGE_LOCATION=0x80A0000 -DMODULAR_FIRMWARE=1 -DMODULE_VERSION=6 -DMODULE_FUNCTION=5 -DMODULE_INDEX=1 -DMODULE_DEPENDENCY=4,2,2011 -DMODULE_DEPENDENCY2=0,0,0 -D_GNU_SOURCE -DLOG_MODULE_CATEGORY="\"app\"" -fno-exceptions -fno-rtti -fcheck-new -std=gnu++14 -c -o ../build/target/user/platform-6-msrc/dhttester.o src/dhttester.cpp In file included from dhttester.ino:4: lib/DHT/src/DHT.h:9:5: warning: "ARDUINO" is not defined, evaluates to 0 [-Wundef] 9 | #if ARDUINO >= 100 | ^ ~~~~~~ Building cpp file: lib/DHT/src/DHT.cpp Invoking: ARM GCC CPP Compiler mkdir -p ../build/target/user/platform-6-mDHT/src/ arm-none-eabi-gcc -DSTM32_DEVICE -DSTM32F2XX -DPLATFORM_THREADING=1 -DPLATFORM_ID=6 -DPLATFORM_NAME=photon -DPLATFORM_GEN=2 -DUSBD_VID_SPARK=0x2B04 -DUSBD_PID_DFU=0xD006 -DUSBD_PID_CDC=0xC006 -DSPARK_PLATFORM -g3 -gdwarf-2 -Os -mcpu=cortex-m3 -mthumb --specs=nano.specs -DINCLUDE_PLATFORM=1 -DPRODUCT_ID=6 -DPRODUCT_FIRMWARE_VERSION=65535 -DUSE_STDPERIPH_DRIVER -DDFU_BUILD_ENABLE -DSYSTEM_VERSION_STRING=2.0.1 -DRELEASE_BUILD -I./inc -I../wiring/inc -I../system/inc -I../services/inc -I../third_party/nanopb/nanopb -I../communication/inc -I../hal/inc -I../hal/shared -I../hal/src/photon -I../hal/src/stm32f2xx -I../hal/src/stm32 -I../hal/network/util -I../hal/network -I../hal/src/photon/api -I../hal/src/photon/include -I../hal/src/photon/wiced/security/BESL/host/WICED/ -I../hal/src/photon/wiced/security/BESL/include -I../hal/src/photon/wiced/security/BESL -I../hal/src/photon/wiced/security/BESL/crypto -I../hal/src/photon/wiced/WWD/include/ -I../hal/src/photon/wiced/platform/include/ -I../hal/src/photon/wiced/platform/GCC/ -I../hal/src/photon/wiced/security/BESL/supplicant/ -I../hal/src/photon/libraries/crypto -I../hal/src/photon/libraries/daemons/DNS_redirect -I../third_party/miniz/miniz -I../platform/shared/inc -I../platform/MCU/STM32F2xx/STM32_USB_Host_Driver/inc -I../platform/MCU/STM32F2xx/STM32_USB_OTG_Driver/inc -I../platform/MCU/STM32F2xx/STM32_StdPeriph_Driver/inc -I../platform/MCU/STM32F2xx/STM32_USB_Device_Driver/inc -I../platform/MCU/STM32F2xx/SPARK_Firmware_Driver/inc -I../platform/MCU/shared/STM32/inc -I../platform/MCU/STM32F2xx/CMSIS/Include -I../platform/MCU/STM32F2xx/CMSIS/Device/ST/Include -I../dynalib/inc -Isrc -I./libraries -Ilib/DHT/src -I. -MD -MP -MF ../build/target/user/platform-6-mDHT/src/DHT.o.d -ffunction-sections -fdata-sections -Wall -Wno-switch -Wno-error=deprecated-declarations -fmessage-length=0 -fno-strict-aliasing -DSPARK=1 -DPARTICLE=1 -Wundef -DSTART_DFU_FLASHER_SERIAL_SPEED=14400 -DSTART_YMODEM_FLASHER_SERIAL_SPEED=28800 -DBOOTLOADER_SDK_3_3_0_PARTICLE -DPARTICLE_DCT_COMPATIBILITY -DSPARK_PLATFORM_NET=BCM9WCDUSI09 -fno-builtin-malloc -fno-builtin-free -fno-builtin-realloc -DLOG_INCLUDE_SOURCE_INFO=1 -DPARTICLE_USER_MODULE -DUSER_FIRMWARE_IMAGE_SIZE=0x20000 -DUSER_FIRMWARE_IMAGE_LOCATION=0x80A0000 -DMODULAR_FIRMWARE=1 -DMODULE_VERSION=6 -DMODULE_FUNCTION=5 -DMODULE_INDEX=1 -DMODULE_DEPENDENCY=4,2,2011 -DMODULE_DEPENDENCY2=0,0,0 -D_GNU_SOURCE -DLOG_MODULE_CATEGORY="\"app\"" -fno-exceptions -fno-rtti -fcheck-new -std=gnu++14 -c -o ../build/target/user/platform-6-mDHT/src/DHT.o lib/DHT/src/DHT.cpp In file included from lib/DHT/src/DHT.cpp:7: lib/DHT/src/DHT.h:9:5: warning: "ARDUINO" is not defined, evaluates to 0 [-Wundef] 9 | #if ARDUINO >= 100 | ^ ~~~~~~ Building cpp file: lib/DHT/src/DHT_U.cpp Invoking: ARM GCC CPP Compiler mkdir -p ../build/target/user/platform-6-mDHT/src/ arm-none-eabi-gcc -DSTM32_DEVICE -DSTM32F2XX -DPLATFORM_THREADING=1 -DPLATFORM_ID=6 -DPLATFORM_NAME=photon -DPLATFORM_GEN=2 -DUSBD_VID_SPARK=0x2B04 -DUSBD_PID_DFU=0xD006 -DUSBD_PID_CDC=0xC006 -DSPARK_PLATFORM -g3 -gdwarf-2 -Os -mcpu=cortex-m3 -mthumb --specs=nano.specs -DINCLUDE_PLATFORM=1 -DPRODUCT_ID=6 -DPRODUCT_FIRMWARE_VERSION=65535 -DUSE_STDPERIPH_DRIVER -DDFU_BUILD_ENABLE -DSYSTEM_VERSION_STRING=2.0.1 -DRELEASE_BUILD -I./inc -I../wiring/inc -I../system/inc -I../services/inc -I../third_party/nanopb/nanopb -I../communication/inc -I../hal/inc -I../hal/shared -I../hal/src/photon -I../hal/src/stm32f2xx -I../hal/src/stm32 -I../hal/network/util -I../hal/network -I../hal/src/photon/api -I../hal/src/photon/include -I../hal/src/photon/wiced/security/BESL/host/WICED/ -I../hal/src/photon/wiced/security/BESL/include -I../hal/src/photon/wiced/security/BESL -I../hal/src/photon/wiced/security/BESL/crypto -I../hal/src/photon/wiced/WWD/include/ -I../hal/src/photon/wiced/platform/include/ -I../hal/src/photon/wiced/platform/GCC/ -I../hal/src/photon/wiced/security/BESL/supplicant/ -I../hal/src/photon/libraries/crypto -I../hal/src/photon/libraries/daemons/DNS_redirect -I../third_party/miniz/miniz -I../platform/shared/inc -I../platform/MCU/STM32F2xx/STM32_USB_Host_Driver/inc -I../platform/MCU/STM32F2xx/STM32_USB_OTG_Driver/inc -I../platform/MCU/STM32F2xx/STM32_StdPeriph_Driver/inc -I../platform/MCU/STM32F2xx/STM32_USB_Device_Driver/inc -I../platform/MCU/STM32F2xx/SPARK_Firmware_Driver/inc -I../platform/MCU/shared/STM32/inc -I../platform/MCU/STM32F2xx/CMSIS/Include -I../platform/MCU/STM32F2xx/CMSIS/Device/ST/Include -I../dynalib/inc -Isrc -I./libraries -Ilib/DHT/src -I. -MD -MP -MF ../build/target/user/platform-6-mDHT/src/DHT_U.o.d -ffunction-sections -fdata-sections -Wall -Wno-switch -Wno-error=deprecated-declarations -fmessage-length=0 -fno-strict-aliasing -DSPARK=1 -DPARTICLE=1 -Wundef -DSTART_DFU_FLASHER_SERIAL_SPEED=14400 -DSTART_YMODEM_FLASHER_SERIAL_SPEED=28800 -DBOOTLOADER_SDK_3_3_0_PARTICLE -DPARTICLE_DCT_COMPATIBILITY -DSPARK_PLATFORM_NET=BCM9WCDUSI09 -fno-builtin-malloc -fno-builtin-free -fno-builtin-realloc -DLOG_INCLUDE_SOURCE_INFO=1 -DPARTICLE_USER_MODULE -DUSER_FIRMWARE_IMAGE_SIZE=0x20000 -DUSER_FIRMWARE_IMAGE_LOCATION=0x80A0000 -DMODULAR_FIRMWARE=1 -DMODULE_VERSION=6 -DMODULE_FUNCTION=5 -DMODULE_INDEX=1 -DMODULE_DEPENDENCY=4,2,2011 -DMODULE_DEPENDENCY2=0,0,0 -D_GNU_SOURCE -DLOG_MODULE_CATEGORY="\"app\"" -fno-exceptions -fno-rtti -fcheck-new -std=gnu++14 -c -o ../build/target/user/platform-6-mDHT/src/DHT_U.o lib/DHT/src/DHT_U.cpp In file included from lib/DHT/src/DHT_U.cpp:22: lib/DHT/src/DHT_U.h:25:10: fatal error: Adafruit_Sensor.h: No such file or directory 25 | #include | ^ ~~~~~~~~~~~~~~~~~~ compilation terminated. ../build/module.mk:286: recipe for target '../build/target/user/platform-6-mDHT/src/DHT_U.o' failed make[2]: *** [../build/target/user/platform-6-mDHT/src/DHT_U.o] Error 1 make[2]: Leaving directory '/firmware/user' ../../../build/recurse.mk:11: recipe for target 'user' failed make[1]: *** [user] Error 2 make[1]: Leaving directory '/firmware/modules/photon/user-part' ../build/recurse.mk:11: recipe for target 'modules/photon/user-part' failed make: *** [modules/photon/user-part] Error 2 ``` The code I used: ```auto // Example testing sketch for various DHT humidity/temperature sensors // Written by ladyada, public domain #include "DHT.h" #define DHTPIN 2 // what digital pin we're connected to // Uncomment whatever type you're using! //#define DHTTYPE DHT11 // DHT 11 #define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321 //#define DHTTYPE DHT21 // DHT 21 (AM2301) // Connect pin 1 (on the left) of the sensor to +5V // NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1 // to 3.3V instead of 5V! // Connect pin 2 of the sensor to whatever your DHTPIN is // Connect pin 4 (on the right) of the sensor to GROUND // Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor // Initialize DHT sensor. // Note that older versions of this library took an optional third parameter to // tweak the timings for faster processors. This parameter is no longer needed // as the current DHT reading algorithm adjusts itself to work on faster procs. DHT dht(DHTPIN, DHTTYPE); void setup() { Serial.begin(9600); Serial.println("DHTxx test!"); dht.begin(); } void loop() { // Wait a few seconds between measurements. delay(2000); // Reading temperature or humidity takes about 250 milliseconds! // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor) float h = dht.readHumidity(); // Read temperature as Celsius (the default) float t = dht.readTemperature(); // Read temperature as Fahrenheit (isFahrenheit = true) float f = dht.readTemperature(true); // Check if any reads failed and exit early (to try again). if (isnan(h) || isnan(t) || isnan(f)) { Serial.println("Failed to read from DHT sensor!"); return; } // Compute heat index in Fahrenheit (the default) float hif = dht.computeHeatIndex(f, h); // Compute heat index in Celsius (isFahreheit = false) float hic = dht.computeHeatIndex(t, h, false); Serial.print("Humidity: "); Serial.print(h); Serial.print(" %\t"); Serial.print("Temperature: "); Serial.print(t); Serial.print(" *C "); Serial.print(f); Serial.print(" *F\t"); Serial.print("Heat index: "); Serial.print(hic); Serial.print(" *C "); Serial.print(hif); Serial.println(" *F"); } ``` I used web editor to verify the example code. ---
**Author:** ![armor](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/armor/32/18398_2.png) [@armor](https://community.particle.io/u/armor)\ **Post date:** [January 27, 2021, 10:33pm UTC](https://community.particle.io/t/dht-library-problem/59210/2 "2021-01-27T22:33:23Z")
If you #include “Particle.h” before the include for “DHT.h” then the ARDUINO not defined should disappear. With the DHT I believe the pierretech library works/works better than the Adafruit version. ---
**Author:** ![majed](https://avatars.discourse-cdn.com/v4/letter/m/71c47a/32.png) [@majed](https://community.particle.io/u/majed)\ **Post date:** [January 28, 2021, 8:59pm UTC](https://community.particle.io/t/dht-library-problem/59210/3 "2021-01-28T20:59:52Z")
I did #include “Particle.h” the same error popped up. I used PietteTech\_DHT library instead and it is working fine now. ---
**Author:** ![armor](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/armor/32/18398_2.png) [@armor](https://community.particle.io/u/armor)\ **Post date:** [January 28, 2021, 10:44pm UTC](https://community.particle.io/t/dht-library-problem/59210/4 "2021-01-28T22:44:49Z")
Good to hear. Can you please mark as Solved. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/particle/original/3X/3/2/3291e3c9351789fe8620ae5bcec8d3fec67ff221.png) [@system](https://community.particle.io/u/system)\ **Post date:** [July 30, 2021, 10:45am UTC](https://community.particle.io/t/dht-library-problem/59210/5 "2021-07-30T10:45:20Z")
Closed on July 30, 2021, 10:45am UTC This topic was automatically closed 182 days after the last reply. New replies are no longer allowed.