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Posted by teralift | Jun 26, 2018 @ 07:05 AM | 9,384 Views
There has been couples of questions on how to connect S.Port and F.Port on Bi-uni-dir inverters on Omnibus F4 V3.

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# Betaflight / OMNIBUSF4SD (OBSD) 3.4.0 Jun 18 2018 / 02:15:39 (72d2fb243) MSP API: 1.39
resource INVERTER 3 NONE
resource PINIO 1 C09

feature RX_SERIAL

serial 5 64 115200 57600 0 115200

set serialrx_provider = FPORT
Implicit settings
set pinio_config = 1,1,1,1
set serialrx_halfduplex = OFF
set serialrx_inverted = OFF

Posted by teralift | Dec 01, 2017 @ 02:06 PM | 14,711 Views
Due to (semi) popular demand, I stopped talking on theory but actually modded the board.

Here's how to break out and enable RX3 to be used as ESC telemetry input.
  • The mod is actually easy if you have some experience with fine soldering, as the MCU pin is convieniently located just across from the connector pin for CRNT/Telemetry signal.
  • The MCU pin to break out is PB11 (RX3), the 3rd pin from the corner.
  • You may want to leave trace to current meter ADC input, so that you can still hook up a compatible 4-in-1 with current sensor output (VIOUT) on the CRNT/Telemetry signal.
  • It is safe to disable the current meter ADC input when telemetry is in use, by issuing the following CLI command.
    resource adc_curr none
  • Here's a diff for the mod. Don't forget to select one of DSHOT for ESC/Motor protocol.
    resource ADC_CURR 1 NONE
    feature ESC_SENSOR
    serial 2 1024 115200 57600 0 115200
    set current_meter = ESC
    set battery_meter = ESC

Posted by teralift | Nov 16, 2017 @ 12:14 PM | 19,419 Views
V3 Worksheet
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Posted by teralift | Oct 05, 2017 @ 04:43 AM | 13,665 Views
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Note that actual label for SBUS/PPM pad is "RC".
Posted by teralift | Sep 22, 2017 @ 10:41 PM | 15,584 Views
BFF4 Wiring Worksheet

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Posted by teralift | Sep 22, 2017 @ 11:02 AM | 57,264 Views
For summarizing compatibility of different cameras with BF3.2's Camera Control feature.

General Note
  • Please read the wiki first:
  • Foxeer Monster and Sparrow series requires "camera_control_internal_resistance = 99".
  • Foxeer Arrow Mini, Arrow Micro and Monster requires additional capacitor for hardware PWM mode to work.


Please provide the following information

Status: OK or NG
Camera model:
Flight controller model:
Firmware version:
Mode: PWM or Software PWM or DAC when available
Resource assignment: camera_control line from resource list output
Pad or through hole label:
Reference voltage: camera_control_reference_voltage
Internal resistance: camera_control_internal_resistance
Control key delay: camera_control_key_delay
Inline register value for PWM and capacitor if software PWM:
Additional comments:
Reported by:
Posted by teralift | Sep 20, 2017 @ 08:33 PM | 16,308 Views
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Posted by teralift | Sep 11, 2017 @ 07:34 AM | 15,678 Views
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Posted by teralift | Aug 30, 2017 @ 11:13 PM | 35,349 Views
UPDATED 2018-01-10
There has been a couple of reports that stock R-XSR is not compatible with the hardware UART + diode method.

UPDATED 2017-10-05
The example is now updated with an expected extension to run Camera Control feature over inverted output, and became Version 2.
Not applicable to general public until the inversion option is merged.

Version 2
OMNIBUS F4 Pro Corners configuration example with following setup:

- UART1 : ESC telemetry input (only uses RX1)
- UART3 : SmartPort (inverted, requires an inline diode on TX; mind the diode direction)
- UART6 : SBUS (only uses RX6)
- SOFTSERIAL1 (on TX1) : SmartAudio
- PA9 : Camera control (on TX6)

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# Betaflight / OMNIBUSF4SD (OBSD) 3.2.0 Oct 5 2017 / 22:44:18 (bbd732be4) MSP API: 1.36

# resources
resource SERIAL_TX 1 NONE
resource SERIAL_TX 11 A09
resource CAMERA_CONTROL 1 C06

# feature
feature LED_STRIP
feature ESC_SENSOR

# serial
serial 0 1024 115200 57600 0 115200
serial 2 32 115200 57600 0 115200
serial 5 64 115200 57600 0 115200
serial 30 2048 115200 57600 0 115200

# master
set serialrx_provider = SBUS
set current_meter = ESC
set battery_meter = ESC
set tlm_halfduplex = OFF
set camera_control_inverted = ON
set camera_control_boost = 4

Version 1
OMNIBUS F4 Pro Corners configuration example with following setup:

- UART1 : ESC telemetry input
- UART6 : SmartPort (inverted, requires an inline diode on TX; mind the diode direction)
- SOFTSERIAL1 (on TX1) : SmartAudio

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# Betaflight / OMNIBUSF4SD (OBSD) 3.2.0 Aug 28 2017 / 12:02:37 (b2cd7294e)

# resources
resource SERIAL_TX 1 NONE
resource SERIAL_TX 11 A09
resource INVERTER 3 C09

# feature
feature ESC_SENSOR

# serial
serial 0 1024 115200 57600 0 115200
serial 2 64 115200 57600 0 115200
serial 5 32 115200 57600 0 115200
serial 30 2048 115200 57600 0 115200

# master
set serialrx_provider = SBUS
set current_meter = ESC
set battery_meter = ADC
set tlm_halfduplex = OFF
Note that SBUS (UART3) and SmartPort (UART6) can be swapped.
Posted by teralift | Aug 29, 2017 @ 01:45 AM | 20,055 Views

Betaflight 3.2 provides fully configurable I2C. This blog entry gives some examples of how to configure them.

There is a couple of basics to successful I2C configuration.

- I2C bus, unlike UART, become active without any user. This means it will occupy designated pin resource and may interfere with other resource uses if there is any.

- I2C bus requires proper bus conditioning including proper wire length and pull-ups. Without these, devices on the bus may not work or give sporadic errors. This blog entry will not help you to work this out.


OMNIBUS F4, AIRBOT F4 and ASGARD variants with TX3/RX3 pads/THs can configure them as I2C2 (SCL = TX3 and SDA = RX3).
resource i2c_scl 2 b10
resource i2c_sda 2 b11
OMNIBUS F4 variants with CH6 pad can configure the CH6 and PWM6 as I2C3 (SCL = PWM6, SDA = CH6).
This may be a better option for those of you who are short of hardware UARTs.
resource i2c_scl 3 a8
resource i2c_sda 3 c9
With BF3.2, barometers can be connected and configured to work on I2C3. Compasses are not ready for this kind of configurability (will be in BF3.3).


OMNIBUS F3 can configure the designated I2C pads/THs as I2C1. Note that I2C1 signals are duplicated as PWM7 and PWM8; configuring I2C1 will void other function assigned to PWM7 and/or PWM8.
resource i2c_scl 1 b6
resource i2c_sda 1 b7

Posted by teralift | Jun 07, 2017 @ 02:24 AM | 20,786 Views

I haven't done this myself. Everything is according to theory.


There were couples of questions here and there about how an external current sensor can be connected to OMNIBUS F3/F4 Pro Series.
Frankly speaking, using an external current sensor, especially that on a separate PDB, simply invalidates what Pro variants were designed for; simple single board solution. If it is necessary to use the separate PDB with the current sensor, non-Pro variant would provide far more cleaner, easy to build and maintain builds.

However, those of you still want to connect the external current sensor to Pro variants, this blog entry explains how to do it.


There are couples of prerequisites.

- Understanding of a separate blog entry Understanding Current Meters to know what you are dealing with.
- Proper skill and tools to perform medium fine soldering.
- An external current sensor with voltage output that swings from 0V to 3.3V in proportion to current flowing.
- An ability to self resolve questions regarding specifications and derivatives of the external current sensor, including current rating, schematics, scale to be used.


The onboard current meter of Pro variants is identical to the typical application circuit for INA169.

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And if you are going to use an external sensor, then you will be having an additional circuit just like it.
You task is to isolate the original sensor block and connect the external sensor block to the point where...Continue Reading
Posted by teralift | Apr 21, 2017 @ 07:39 AM | 31,305 Views

This is a note for users of OMNIBUS and AIRBOT F4 family those who wishes to isolate ESC_5V rail from rest of the FC so that it could be used to power servos on multi-servo vehicle such as a four control surface airplane.


OMNIBUS and AIRBOT F4 families all share a same design regarding 5V power supply, which is shown below.

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The diode triplet is used to select the highest voltage of the three 5V sources, which are ESC_5V, USB_VBUS, and LDO_5V or SBEC_5V. (These diodes also prevents reverse powering unselected sources.)

To power the ESC_5V with an external 5V source dedicated for servo power, one of the diode triplet, Dx, must be removed.


In theory, you can use a DMM to determine where the Dx is by testing continuity between a relatively large SMD device (marked Dn with diode icon --i>| in a pin map if you have any) and one of the ESC_5V through-holes/pads. Result of measuring for some of the family members are given below, but builders are advised to verify the continuity before proceeding.

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Description: ...Continue Reading
Posted by teralift | Apr 18, 2017 @ 11:07 AM | 19,921 Views

Collection of information for building tricopters with OMNIBUS family FC.

Servo Signal Mapping

OMNIBUS AIO and Pro (F3)

With OMNIBUS AIO and Pro, motor 3 (PWM3) or motor 4 (PWM4) can be assigned to a tail servo.

resource servo 1 a3 # For motor 3 (PWM3)
resource servo 1 a2 # For motor 4 (PWM4)

With OMNIBUS F4 family, motors 1 & 2 and 3 & 4 each shares a timer, so one of these signals can't be assigned to a tail servo.

Use motor 5 or motor 6 (labelled PWM5 and PWM6 respectively) instead.

Note that with 3.1.7 and later, LED strip signal is available at designated signal connector/through-hole, so PWM5 and PWM6 are free for use, except for OMNIBUS F4 AIO (the original F4 AIO without SDCARD) in which PWM5 is used for LED strip signal.

resource servo 1 a1 # For PWM5
resource servo 1 a8 # for PWM6
Servo Configuration and Setting

The tail servo will be automatically configured using the first (and only) servo assigned in the signal mapping section above, and it will appear as "servo 5" (zero origin) in the servo tab of the configurator.

Servo View

Signal to the tail servo can be monitored using motors tab of the configurator. "Servo 6" (one origin) is the tail servo.
If you setup the angle mode, you will be able to see the servo 6 respond to yaw movement of the tricopter.

Servo Powering

Servos are considered dirty in terms of power, and it is...Continue Reading
Posted by teralift | Mar 15, 2017 @ 04:37 PM | 20,951 Views
Measure the DC resistance between OUT pin of INA169 and ground.

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For the reference, this is OMNIBUS F3 Pro circuit.

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Posted by teralift | Feb 19, 2017 @ 08:55 PM | 27,013 Views
Here are side-by-side comparison pics for two revisions of OMNIBUS F4 Pro boards.

LEFT: OmnibusF4-Pro-0A / OMNIBUS F4 Pro (v2)
RIGHT: OmnibusF4-Pro-0A-V2 / OMNIBUS F4 Pro v3

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Note that v3 requires solder jumper to be installed to use the SBUS/PPM pin header.
Posted by teralift | Feb 19, 2017 @ 08:49 PM | 57,482 Views
Here are the side by side comparison pics between two revisions of non-Pro OMNIBUS F4, with SDCARD.

LEFT: OmnibusF4-0B-V1 (OMNIBUS AIO F4 V2)
RIGHT: OmnibusF4-0B-V3

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On OmnibusF4-0B-V3 (OMNIBUS AIO F4 V3), SBUS/PPM header is connected to UART6, as oppose to UART1 on F4 V2.
Posted by teralift | Feb 10, 2017 @ 09:28 AM | 22,540 Views
Ever dreamed of having one more timer capable pin on your OMNIBUS F3 or F3 Pro, so that you can hook up your TBS SmartAudio or IRC Tramp or S.PORT telemetry?

If you use PPM, then you will have an extra UART

No, that's not what I wanted to tell you.

If you are using S.BUS or other Serial RX receivers, then you can move your receiver input from SBUS/PPM header (J8) to UART3 RX (F3: J22/PWM6, F3 Pro: J12/PWM6), and make the SBUS/PPM header dedicated for PPM signal.

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- You may have to re-do your jumper work on SBUS/PPM selection jumpers.

- Newer revision may have solder jumper with SBUS bridged by default. In this case, you have to cut the bridge and install a solder jumper for PPM.

The PPM signal is connected to MCU pin PB4, and you can use this for single-wire software serial available in BF3.1.6 and later.

OMNIBUSF3 / F3 Pro can test if this really works by using the firmware in Exotic OMNIBUS.
Posted by teralift | Jan 09, 2017 @ 02:39 AM | 27,062 Views
Another signal that comes in handy with exotic configurations on OMNIBUS F4 Series and AIRBOT F4 is PPM, provided that the PPM is not used to connect to a receiver.

These boards have pin header triplets for shared SBUS/PPM connection, and there are two jumpers close to the signal pin. On OMNIBUS Series, these jumpers are marked as SBUS and PPM (Figure 1). On AIRBOT F4, these are not marked, but cross referencing with the pin map reveals they are called R19 and R20 (Figure 2).

These jumpers are usually both closed, connecting the SBUS/PPM header pin to both PB14 (OMNIBUSF4 and AIRBOTF4, PB8 for OMNIBUSF4SD) and PA10 (UART1 RX) through an inverter circuit (Figure 3).

So, if you are using S.BUS, you can remove the PPM jumper and break out the PB14 pin for other uses (Figure 4).

Figures 5, 6 and 7 shows actual implementation.

OMNIBUS F4 V2 doesn't have jumper resistors, but pads. It may be easier to do this mod.
Posted by teralift | Jan 08, 2017 @ 07:44 AM | 30,598 Views
Firmwares under "[BF] Fully configurable software serial" heading in the Exotic OMNIBUS blog entry are produced directly from Betaflight PR "Configurable serial port pin assignment #1849".

With these firmwares, you have maximum flexibility of configuring software serial ports; you can assign two unused timer capable pins, with some constraints, to software serial tx and rx pins.

Introductory Example: Stock OMNIBUS F4

With a stock OMNIBUSF4, you have a pair of pins you can assign to the software serial port; PWM5 and PWM6. PWM5 may be used for LED strip on your build, but we will disable it here as an example.

To assign PWM5 to SOFTSERIAL1 TX and PWM6 to RX, use the following resource commands.
resource motor 5 none
resource motor 6 none
resource led_strip none
resource serial_tx 11 a1
resource serial_rx 11 a8
First three "none" assignments releases the PWM5 and PWM6 from other uses. They may not be required, but better to be sure than sorry.
The "11" is the identifier for SOFTSERIAL1. For SOFTSERIAL2, use "12".

With this resource assignment, you can turn on SOFTSERIAL feature in Config tab, assign a function to SOFTSERIAL1 in Ports tab and you are good to go.

Finding More Pins

What if we want to keep the LED strip on PWM5 and still use a software serial port?

If you can solder a fine gauge wire to a 0.8mm diameter pad, then you have three more pins you can use to configure the...Continue Reading
Posted by teralift | Dec 26, 2016 @ 02:39 PM | 25,707 Views
The firmware in this entry has been superseded by BF v3.1.0.
Though, you can still use the procedure for downloading and executing up to date configurator.

This blog entry tells you how to flash your OMNIBUS F4 V2 and OMNIBUS F4 Pro with the correct firmware.

As of today (2016-12-27), OMNIBUS F4 V2 and OMNIBUS F4 Pro needs developer version of the 3.1 firmware.

The firmware
This firmware is available for download from Boris's build server:

Download a recent build, and select OMNIBUSF4SD.hex

The configurator
The new firmware requires up to date configurator to properly configure the board, especially the OSD tab.
(a) Goto Betaflight Configurator github.
(b) Press the green "Clone or Download", select "Download ZIP", save and expand it at your favorite location.
(c) In Chrome, open "Extensions Manager", check "Developer Mode" and press "Load unpacked extension...".
(d) Select the location you have saved your files in (b).
(e) Launch.