1.The link for the schematic of the SEN0189 Gravity: Analog Turbidity Sensor for Arduino board is here:

https://github.com/Arduinolibrary/DFRobot_Turbidity_sensor/blob/master/SEN0189%20Turbidity%20sensor(V1.0)%20schematic.pdf

2.You do not have to, you can adjust the threshold potentiometer on it to do calibration.

3.No, it can only powered by 5V.

ToF Laser Ranging Module for Outdoor (15m) (SKU:SEN0524) is a pretty sensitive sensor and should react quickly with the change in distance.

Could you please share a video via Google drive? So we can understand what problem you are facing exactly.

Hello

We do not have microbit environment science extension board marqued as (v3.0). Did you mean Environment Science Expansion Board V2.0 for micro:bit (SKU:MBT0034)? https://www.dfrobot.com/product-2194.html

If yes, could you please try sending a message to your Thingspeak, and check whether your board has connected to your wifi correctly or not?

Your code seems right, However, it is recommended to add a delay (for 1 second, for example) at the end of forever block, which can avoid some problem.

We have tested the sensor without RX and TX connected, and it worked fine.

It could be a hardware problem.

Please contact techsupport@dfrobot.com for after-sell service.

Please change the baud rate of the serial monitor to 57600, and you will get the right result.

Could you please try comment these lines in the codes? it could be the code stack at reading the serial port, while the RX and TX is unplugged.

Could you please share a screenshot of your setting(board manager) and the error message? It can help us find the problem.

Could you please try connecting the Gravity: Factory Calibrated Electrochemical CO Sensor to your PC via TTL to USB converter?

You can try setting the software to send commands as shown above and see if you can enter passive mode.

If it doesn't work, that could be an hardware issue.

Please calibrate the EC sensor. As it read the data from EEPROM as the parameter for calculation, you need to first calibrate and save the right parameter value into the EEPROM.

About how to calibrate the sensor, see the below link.

https://wiki.dfrobot.com/Gravity__Analog_Electrical_Conductivity_Sensor___Meter_V2__K%3D1__SKU_DFR0300 

The FireBeetle package is for Firebeetle series development board only, you may face compatibility issue when you use other ESP32 board.

Please follow this instruction to install your board properly.

https://randomnerdtutorials.com/installing-the-esp32-board-in-arduino-ide-windows-instructions/

Which development board you are using? The example code only work for Arduino UNO.

mmWave Radar - Human Presence Detection Sensor(SKU:SEN0395) can be used without serial connection, as long as you modify the mode.

Could you please change the start-up Mode to 1m? So it will work directly as on as you power it.

Here is the API.

You can find more information in our WIKI page.

https://wiki.dfrobot.com/mmWave_Radar_Human_Presence_Detection_SKU_SEN0395

You can first try hardserial connection, via TX and RX pins on the board.

SoftwareSerial library is included in arduino IDE, please download the 1.8.19 version.

The working sketch is provide in wiki, see the picture below.

For SIM808 GPS/GPRS/GSM arduino shield(SKU:TEL0097), the GPS function will only work if you set yhe GPS antenna outside before it can obtain a stable GPS location data output.

Also, could you please try AT command? See whether the module work properly.

For more details see the WIKI page here.

https://wiki.dfrobot.com/SIM808_GPS_GPRS_GSM_Shield_SKU__TEL0097

Could you please share a screenshot of your serial monitor and your code?

If it didn't detect the sensor, according to the code, it should print "IIC init failed, please check if the wire connection is correct"

If you do IIC scanning and find no device, it could be a poor connection, please change your cable.

Otherwise, it could be a hardware failure, please contact DFrobot via email for help.

Could you please follow the WIKI page of A02YYUW Waterproof Ultrasonic Sensor(SKU:SEN0311)?

See https://wiki.dfrobot.com/_A02YYUW_Waterproof_Ultrasonic_Sensor_SKU_SEN0311

Also, could you share your wiring? This can help us find the problem.

Have you change the min.c file befor doing gcc?

For more information about RS485 Wind Direction Transmitter(SKU:SEN0482), please see the link below.

https://wiki.dfrobot.com/RS485_Wind_Direction_Transmitter_SKU_SEN0482#target_5

Hi

Gravity: Analog Water Pressure Sensor(SKU:SEN0257) is a pure analogue sensor, which means that it must work with ADCs like ads1115 or ADCs built-in development board.

For more detail, see the link below.

https://wiki.dfrobot.com/Gravity__Water_Pressure_Sensor_SKU__SEN0257

According to the wiki page of ToF Laser Ranging Module for Outdoor (15m)(SKU:0524), the dis_status means that whether the measurement of distance is valid.

signal_strengh indicates the strength of the current return signal, the larger the value, the stronger the return signal.

For more information, see the wiki page.

https://wiki.dfrobot.com/SKU_SEN0524_ToF_Outdoor_Laser_Ranging_Module_15m 

It is quite abnormal, the package of Gravity: Analog Industrial pH Sensor / Meter Pro Kit V2(SKU:SEN0169-V2), this metal piece is not included.

However, if the probe is fine, just use it.

If the probe does not behave normally, please contact DFrobot for the after-sell service.