From 20837a135346bd6458c90c222e4846f194849be4 Mon Sep 17 00:00:00 2001 From: Joel Fuster Date: Fri, 2 Jan 2015 20:27:57 -0500 Subject: [PATCH] Mixer and SBUS documenation updates --- docs/Mixer.md | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++ docs/Rx.md | 6 +++++- 2 files changed, 63 insertions(+), 1 deletion(-) create mode 100644 docs/Mixer.md diff --git a/docs/Mixer.md b/docs/Mixer.md new file mode 100644 index 000000000..777cae38d --- /dev/null +++ b/docs/Mixer.md @@ -0,0 +1,58 @@ +# Mixer + +Cleanflight supports a number of mixing configurations as well as custom mixing. Mixer configurations determine how the servos and motors work together to control the aircraft. + +## Configuration + +To use a built-in mixing configuration, you can use the Chrome configuration GUI. It includes images of the various mixer types to assist in making the proper connections. See the Configuration section of the documentation for more information on the GUI. + +You can also use the Command Line Interface (CLI) to set the mixer type: + +1. Use `mixer list` to see a list of supported mixes +2. Select a mixer. For example, to select TRI, use `mixer TRI` +3. You must use `save` to preserve your changes + +## Supported Mixer Types + +| Name | Description | Motors | Servos | +| ------------- | ------------------------- | -------------- | ---------------- | +| TRI | Tricopter | M1-M3 | S1 | +| QUADP | Quadcopter-Plus | M1-M4 | None | +| QUADX | Quadcopter-X | M1-M4 | None | +| BI | Bicopter (left/right) | M1-M2 | S1, S2 | +| GIMBAL | Gimbal control | N/A | S1, S2 | +| Y6 | Y6-copter | M1-M6 | None | +| HEX6 | Hexacopter-Plus | M1-M6 | None | +| FLYING_WING | Fixed wing; elevons | M1 | S1, S2 | +| Y4 | Y4-copter | M1-M4 | None | +| HEX6X | Hexacopter-X | M1-M6 | None | +| OCTOX8 | Octocopter-X (over/under) | M1-M8 | None | +| OCTOFLATP | Octocopter-FlatPlus | M1-M8 | None | +| OCTOFLATX | Octocopter-FlatX | M1-M8 | None | +| AIRPLANE | Fixed wing; Ax2, R, E | M1 | S1, S2, S3, S4 | +| HELI_120_CCPM | | | | +| HELI_90_DEG | | | | +| VTAIL4 | Quadcopter with V-Tail | M1-M4 | N/A | +| HEX6H | Hexacopter-H | M1-M6 | None | +| PPM_TO_SERVO | | | | +| DUALCOPTER | Dualcopter | M1-M2 | S1, S2 | +| SINGLECOPTER | Conventional helicopter | M1 | S1 | +| ATAIL4 | Quadcopter with A-Tail | M1-M4 | N/A | +| CUSTOM | User-defined | | | + + +## Servo filtering + +A low-pass filter can be enabled for the servos. It may be useful for avoiding structural modes in the airframe, for example. Currently it can only be configured via the CLI: + +1. Use `set servo_lowpass_freq_idx = nn` to select the cutoff frequency. Valid values range from 0 to 99. +2. Use `set servo_lowpass_enable = 1` to enable filtering. + +The actual cutoff frequency is determined by the value of the `looptime` variable and the selected index. +The formula is: +`Frequency = 1000000 * (servo_lowpass_freq_idx + 1)*0.0025 / looptime )` + + +For example, if `servo_lowpass_freq_idx` is set to 40, and looptime is set to the default of 3500 us (0.0035 s), the cutoff frequency will be 29.3 Hz. + + diff --git a/docs/Rx.md b/docs/Rx.md index 96c334067..361916ce1 100644 --- a/docs/Rx.md +++ b/docs/Rx.md @@ -47,7 +47,11 @@ http://www.lemon-rx.com/shop/index.php?route=product/product&product_id=118 ### S.BUS -16 channels via serial currently supported. +16 channels via serial currently supported. See the Serial chapter in the documentation for a configuration example. + +* In most cases you will need an inverter between the receiver output and the flight controller hardware. +* Softserial ports cannot be used with SBUS because it runs at too high of a bitrate (1Mbps). Refer to the chapter specific to your board to determine which port(s) may be used. +* You will need to configure the channel mapping in the GUI (Receiver tab) or CLI (`map` command). These receivers are reported working: