常见问题

IoT:bit is an expansion board designed for BBC Micro:bit, aimed to improve the accessibility of Micro:bit. With IoT:bit, not only the original features can be performed easily, but also make up for the deficiency of Micro:bit – Internet access ability. Using IoT:bit with Micro:bit allows Micro:bit to access different internet resources, making it able to participate in IoT projects.

IoT:bit provides three power supply options, they are USB (5V), lithium battery (3.7V),  Dry cell with battery box (AA, 1.5V*4). Users can either use one of them to power up the IoT:bit expansion board, Micro:bit and the connected sensor/actuator.

No, different power supplies should not be used at the same time. Some power supply may interfere with another power supply to cause damage, worst case may cause fire, DON’T DO IT!

According to Micro:bit’s official website[https://tech.microbit.org/hardware/powersupply/], the power chip on Micro:bit can only supply up to 120ma, that is absolutely not enough for driver IoT:bit. Please be sure to power from the IoT:bit but not from Micro:bit.

IoT:bit use UART protocol to communicate with Micro:bit, it is connected to Pin P8 and P16 through the edge connector. So Micro:bit can use Serial command to send commands to IoT:bit.

Check the direction of the Micro:bit installed on the edge connector. The side of the Micro:bit with LEDs and two buttons should be facing toward the same direction of the instruction arrow printed on board. If reversed, it will not work and may damage the Micro:bit and IoT:bit. Also, please check the power LED on the Wi-Fi Module whether it is turned or not.

IoT:bit provides a makecode extension for Micro:bit to communicate with IoT:bit. Please refer to the tutorial on  https://smarthon-docs-en.readthedocs.io/en/latest/smartcity/3_getstart.html .

If you do no need smartcity module but just iot function in case, the IoT:bit extension is also available in https://github.com/smarthon/pxt-iot-bit

In the IoT:bit extension, after initializing the IoT:bit, it can return the firmware version from IoT:bit->ESP->firmware version. Showing it on the OLED display or LEDs array, if it can show up, means the communication is fine, and the firmware is working.

IoT:bit allows the user to decide to use the buzzer on the expansion board or not, so provide a switch to control the connection from Micro:bit P0 to buzzer. Check the switch at the top-right corner position, follow the icon instructure to switch it to connected position to let Micro:bit access the buzzer. 

Check the switch at the top-right corner position, following the icon instructure to switch it to disconnected position. It can avoid the buzzer interfering with the signal in Pin P0.

Check the power supply output current, it is suggested to use 5V 1A power supply when using the heavy loading actuators. When using the lithium battery or Dry Cell, check their remaining power and the specification of their current output ability. The entire IoT:bit designed to operate in maximum 1A current, so the number of heavy loading actuators should be limited. Normally, the maximum 2-3 servo or 1-2 heavy actuator can be used for iot:bit. When you need to use multiple heavy loading actuators, consider using an external driver board with an independent power supply to work with IoT:bit.

here may be several reasons for the IoT:bit cannot connect to the internet.

1. Router is too far away
2. No that AP actually
3. The typo on SSID/PWD (No space or special character)
4. The battery have run out, please change to new battery or use USB to provide stable power supply to IoT:bit
5. Double check your AP is in 2.4Ghz Mode, but not in 5Ghz, IoT:bit using ESP32 chip do not support 5Ghz WiFi
6. Follow the best practice on using the iot:bit

i.Load the program into the micro:bit (Micro:bit not connected to iot:bit

ii. Take the USB out from micro:bit

iii. Insert the micro:bit to iot:bit

iv. Switch on the iot:bit

When compared to other wifi extension boards on the market, IoT:bit has few notable advantages.

IoT:bit using ESP32 instead of ESP8266. ESP32 is a new generation of WiFi module from Espressif. When compared to ESP8266 which is commonly used on other products, it has a great upgrade on hardware specifications, the CPU is from single core to dual core; frequency nearly double; SRAM and Flash ROM size increase for 2 and 8 times respectively. It helps to improve the performance and stability when doing internet transmission.

IoT:bit provides three types of power supply option, it can let the user choose the best method to power the device in different situations. When used in some place that is fixed and has a stable power supply, such as on a desktop, indoor room, it can use USB to power up easily. When needed outdoors, it can switch to use an AA battery holder for better portability. If using a heavy power consumption module, choosing to use a rechargeable lithium battery is a better option for saving the spending on AA battery.