Development Kit¶
The W-Modbus Development Kit simplifies the evaluation and prototyping of the W-Modbus module. The kit contains the parts needed to build a prototype and integrate it into your product, which includes:
- 2x W-Modbus Devices
- 1x W-Modbus Development Board
- 1x W-Modbus Shield
- 5x W-Modbus OEM Modules
- 1x Patch Antenna
- 1x Dipole Antenna
- 1x Outdoor Dome Antenna
- 1x Micro USB Cable
The W-Modbus Development Board has the W-Modbus module mounted. The board is powered by USB or the pin headers. A development shield with an RS485 interface is included and can be attached to the pin headers. The shield also includes headers for the SPI or UART management pins. The module with the shield attached is shown in the figure below.
Demonstration video¶
The video embedded below, "One-Hour Engineering Prototype Challenge", demonstrates how prototyping can be done from scratch using the W-Modbus development kit.
Powering the development board¶
The development board can be powered using the included USB cable, by connecting it to the J6 micro USB port, labeled "USB IMCU". If the board does not power on using this method, confirm that this port is selected by the power supply selector (S1).
The jumpers and switches are factory set and should not be changed. In the event of a malfunction, remove the shield from the main board and check the jumpers and the position of the DIP switch positions.
Switch S1 should be set to "USB IMCU", while J1, J9 and J10 header pins should be connected with jumpers. See the jumper positions in the picture below.
For J1, VDD and VDD MIRA should be connected. J9 and J10 are reserved.
Shield¶
The shield has additional components to simplify getting started with the W-Modbus Module, like an RS485 interface (J3), SPI (J4) and UART management (J5). It also has a bootloader entry button and LEDs to indicate power OK, as well as traffic on the communication buses. The shield is powered by the development board.
Configure the device using the SPI or UART management interfaces.
Pins¶
The pins for the W-Modbus module can be found in the Pin assignment section.
Relevant pins for the shield can be found below. UART_TXD and UART_RXD pins
are shown below so the RS485 IC can be bypassed.
| Pin | Name | Pin type | Description |
|---|---|---|---|
| J4.1 | CS | Digital output | SPI Chip select, active low |
| J4.3 | MISO | Digital output | SPI Master In, Slave Out |
| J4.5 | MOSI | Digital input | SPI Master Out, Slave In |
| J4.7 | SCK | Digital input | SPI Clock |
| J4.9 | IRQ | Digital output | SPI Interrupt signal, active low |
| J5.1 | UART_MGMT_TXD | Digital output | UART Management TXD |
| J5.3 | UART_MGMT_RXD | Digital input | UART Management RXD (3.3V Max) |
| J5.5 | GND | Power | Signal ground |
| J5.7 | 3V3 | Power | 3.3 V supply output |
| J5.9 | BOOTLOADER / Push Button | Digital input | Bootloader entry (3.3V Max) (Pulled-up) |
| JP12.2 | UART_TXD | Digital output | UART TXD |
| JP1.4 | UART_RXD | Digital input | UART RXD (3.3V Max) |
| JP1.3 | RS485_DE | Digital output | RS485 Driver Enable |
| JP1.3 | RS485_RE | Digital output | RS485 Receive Enable (active low) |
Legacy shield¶
Devkits shipped pre-2025 come with an earlier version of the shield, which lacks some quality-of-life improvements like indicator LED's and pushbutton. However, basic functionality like RS485, SPI, and UART management remains.
Note that the LED's, three pole switch, and DIP switch are not used by the W-Modbus module. Configure the device using the SPI or UART management interfaces.
Pins¶
The pins for the W-Modbus module can be found in the Pin assignment section.
Relevant pins for the shield can be found below. UART_TXD and UART_RXD pins
are shown below so the RS485 IC can be bypassed.
| Pin | Name | Pin type | Description |
|---|---|---|---|
| J4.1 | CS | Digital output | SPI Chip select, active low |
| J4.3 | MISO | Digital output | SPI Master In, Slave Out |
| J4.5 | MOSI | Digital input | SPI Master Out, Slave In |
| J4.7 | SCK | Digital input | SPI Clock |
| J4.9 | IRQ | Digital output | SPI Interrupt signal, active low |
| JP12.2 | UART_TXD | Digital output | UART TXD |
| JP1.4 | UART_RXD | Digital input | UART RXD (3.3V Max) |
| JP12.5 | UART_MGMT_TXD | Digital output | UART Management TXD |
| JP12.8 | UART_MGMT_RXD | Digital input | UART Management RXD (3.3V Max) |
| JP10.3 | BOOTLOADER / Push Button | Digital input | Bootloader entry (3.3V Max) (Pull-up) |
Antennas¶
The kit includes 3 different antennas of varying size, form factor and performance for evaluation.
Compact Patch Antenna¶
The compact patch antenna is a flat patch adhesive mount antenna for ABS or PC plastic enclosure. It is an indoor ultra-compact antenna with adhesive backside for easy "peel and stick" mounting. The antenna is designed for mounting inside on a ABS/PC plastic enclosure of 2 mm thickness. This antenna has a moderate performance compared to the other antennas, and range would typically be limited to 500 meters line of sight when used by the W-Modbus module.
| Manufacturer product number | Digi-Key order code |
|---|---|
| YF0027AA | WM12218-ND |
 |
|
| Alternative part: | |
| 1461530100 | WM12218-ND |
 |
Dome antenna for outdoor use¶
The dome antenna from Linx Technologies can be used for relatively compact mounting in outdoor environments. This antenna needs to be mounted on a grounded metal surface for optimal performance. Full range performance of up to 1500 meters line of sight can be expected using this antenna together with the W-Modbus module.
| Manufacturer product number | Digi-Key order code |
|---|---|
| ANT-DB1-WRT-MON-UFL | ANT-DB1-WRT-MON-UFL-ND |
 |
2.15 dBi Omni antenna¶
The omni-directional antenna from LumenRadio provides the best performance out of the options provided with the development kit. Since it uses an RP-TNC male connector, it requires an IPEX adapter cable. Full range performance of up to 1500 meters line of sight can be expected using this antenna with the W-Modbus module.
| Lumenradio order code | Antenna cable order code |
|---|---|
| 104-1001 | 102-2006 |
 |