Mono: DllImport unable to load library 'MonoPosixHelper'

Hi All
I have a Feather7v1 and I’m trying to connect a WIT accelerometer (Tilt angle) module C#_SDK Quick Start - WITMOTION SDK
I’ve followed their SDK docs on GitHub - WITMOTION/WitStandardProtocol_JY901: 维特协议标准精度示例程序(c#) and everything is compiling.
In runtime though, I get the following error.

Mono: DllImport unable to load library 'MonoPosixHelper'.
Mono: DllImport unable to load library 'MonoPosixHelper'.
Mono: DllImport unable to load library 'MonoPosixHelper'.
exception initializing Accel: System.DllNotFoundException: MonoPosixHelper assembly:<unknown assembly> type:<unknown type> member:(null)
at (wrapper managed-to-native) System.IO.Ports.SerialPortStream.open_serial(string)
at System.IO.Ports.SerialPortStream..ctor (System.String portName, System.Int32 baudRate, System.Int32 dataBits, System.IO.Ports.Parity parity, System.IO.Port
.StopBits stopBits, System.Boolean dtrEnable, System.Boolean rtsEnable, System.IO.Ports.Handshake handshake, System.Int32 readTimeout, System.Int32 writeTimeout, System.Int32 readBufferSize, System.Int32 writeBufferSize) [0x00006] in <cea975cc30894a9a8ff0f0086089e710>:0
at System.IO.Ports.SerialPort.Open () [0x0006f] in <cea975cc30894a9a8ff0f0086089e710>:0
at Wit.SDK.Modular
Sensor.Modular.Connector.Role.SPConnector.Open () [0x000fd] in <8aca52c947a94292893c7f745f906a13>:0
at Wit.SDK.Modular.Sensor.Device.DeviceModel.OpenDevice () [0x0005e] in <8aca52c947a94292893c7f745f906a13>:0
at Wit.SDK.Modular.WitSensorApi.Modular.JY901.JY901.Open () [0x00000] in <9e243c6c42b6421c835e3001696e5305>:0
at bike1.MeadowApp.Initialize () [0x0040c] in <9e243c6c

Can anyone suggest where I should be looking for a solution.

Any help appreciated

Hi Michael,

I’m not sure what would cause that error - are you able to share your code?



Hi Adrian

The code running is attempting to open a serial port on “COM1” it is done through the 3rd party library.
It’s error is triggered on “accel.Open()”

            accel.OnRecord += JY901_OnRecord;