Multiwii Write Actuators
Writes the commands for the motors to the auto-pilot.
Library
QUARC Targets/Communications/Multiwii
Description
The Multiwii Write Actuators block uses the Multiwii protocol on the input stream to send a command to the aircraft to
write the commands for the motors to the auto-pilot. The Multiwii Write Actuators block sends a MSP_SET_MOTOR
message to the auto-pilot.
This block is designed to be used with blocking I/O. It is typically used with a stream connected to a serial port. To open the stream a Multiwii Connect block should be used.
The input of the block is a fixed or variable-sized vector. The units depend on the Input units parameter. The order of the actuators depends on the auto-pilot.
A copy of the stream is also output so that the Multiwii blocks may be chained together.
If an error occurs, then the block returns a negative error code at its err output. The Compare to Error block may be used to check for specific error codes. If the stream is not valid because it is not yet connected, the err output will be zero since this condition is expected and the validity of the stream may be checked using the con output of the Multiwii Connect block.
Helpful Hints
Other uses of this block
Although it is intended for use in the main diagram with the other Multiwii
blocks, the
Multiwii Write Actuators
block may be used
with the Advanced stream blocks, even in an asynchronous thread.
Input Ports
stm
A reference to the stream created by the Multiwii Connect block. If a connection has not yet been established, then the err output of the Multiwii Write Actuators block will be zero.
val
This input depends on the Input units parameter. Each element of the input vector corresponds to a separate actuator. However the data type and range changes depending on the input units. Refer to the Input units parameter for details.
This input may be a fixed or variable-sized vector.
Output Ports
stm
A reference to the stream. This output is merely a copy of the stm input. Providing this output makes it much easier to establish the execution order of Multiwii blocks in the diagram because Simulink generally executes daisy-chained blocks in sequence.
err
An int32 value indicating whether the message was sent successfully. This value will be positive if message was sent successfully. It will be zero if no message was sent. If an error occurs then this value is a negative error code. See Error Codes for the different error codes and their values. Use the Compare to Error block rather than the error code itself to check for specific error codes. To check for errors in general use the Compare to Zero block to check whether the err output is less than zero.
Parameters and Dialog Box
Input units
This parameter determines the data type and units of the val input. The table below shows the input for each of the different units:
|
Units |
Data Type |
Description |
|---|---|---|
|
Bipolar percentage |
double |
Each element maps the input range of [-1,1] to the typical [1000,2000] range such that -1 becomes 1000, 0 becomes 1500 and 1 becomes 2000. Any values outside this range are mapped according to the same affine transformation. These units are useful when the RC data represent -100% to 100% throttle. |
|
Unipolar percentage |
double |
Each element maps the input range of [0,1] to the typical [1000,2000] range such that 0 becomes 1000 and 1 becomes 2000. Any values outside this range are mapped according to the same affine transformation. These units are useful when the RC data represent 0 to 100% throttle. |
|
Seconds |
double |
Each element maps the input range of [0.001,0.002] to the typical [1000,2000] range such that 0.001 becomes 1000 and 0.002 becomes 2000 so that the input is the RC pulse width in seconds. Any values outside this range are mapped according to the same affine transformation. These units are useful when the RC data are being used to drive PWM pulse widths via the HIL blocks. |
|
Microseconds (raw) |
uint16 |
Each element is the raw RC value, which is the RC pulse width in microseconds. |
Write only when the input changes
Check this option to have the block only write new motor commands when the input changes. If this option is not checked then the block will write new motor commands every time it executes.
This option makes it easier to use the block, since it typically makes a Triggered Subsystem unnecessary when the option is checked.
Targets
|
Target Name |
Compatible* |
Model Referencing |
Comments |
|---|---|---|---|
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
||
|
Yes |
Yes |
Last fully supported in QUARC 2018. |
|
|
Rapid Simulation (RSIM) Target |
Yes |
Yes |
|
|
S-Function Target |
No |
N/A |
Old technology. Use model referencing instead. |
|
Normal simulation |
Yes |
Yes |
See Also
Copyright ©2024 Quanser Inc. This page was generated 2024-04-16. Submit feedback to Quanser about this page.
Link to this page.