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Both boards are plugged in together via header pins. The following figure shows the complete NB | DEV KIT and its components.
EX-EVL210 USB/RS232 serial adapter board
UART Interface selection
The EVL210 has three serial UART interfaces, which can be used to interact with the EX-COM210 NB-IoT board:
Label | Connector type | Voltage level | Comments |
|---|---|---|---|
J102 | female screw terminals | 3.3V | pin mapping: U1 = TX, U2 = RX, U3 = GND |
J103 | micro USB connector | 5V | The micro USB connection is also the power supply, therefore it must always be connected (even if not used as UART). |
J104 | RS232 connector | 12V |
In order to the select the desired serial interface, the jumper on J101 has to be changed:
Interface | Connected jumper pins |
|---|---|
| screw terminals | J4 & J2 |
| mirco USB | J1 & J2 |
| RS232 | J3 & J2 |
Peripherals
The reset button triggers a hard reset of the EX-COM210 NB-IoT board. Any state of the microcontroller and the NB-IoT modem will be reset, therefore a (Re-)Attach is needed.
There are also three status LEDs:
- LED1 indicates the power status of the EX-COM210 board
- LED2 indicates if the microcontroller is updating its status; in normal situations the LED should blink every second
- LED3 indicates if the NB-IoT modem is attached to a NB-IoT cell (LED on = attached, LED off = detached)
- LED4 indicates if a modem procedure (attach, transmit, receive, ...) is ongoing
The EX-COM210 NB-IoT communication board
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