# PX4 Dev Call: April 27, 2022

**URL:** <https://discuss.px4.io/t/px4-dev-call-april-27-2022/27066>\
**Category:** PX4 Autopilot\
**Created:** [April 20, 2022, 5:00pm UTC](https://discuss.px4.io/t/px4-dev-call-april-27-2022/27066 "2022-04-20T17:00:51Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![rroche](https://discuss.px4.io/user_avatar/discuss.px4.io/rroche/32/17635_2.png) [@rroche](https://discuss.px4.io/u/rroche)\
**Post date:** [April 20, 2022, 5:00pm UTC](https://discuss.px4.io/t/px4-dev-call-april-27-2022/27066/1 "2022-04-20T17:00:51Z")

</div>

# April 27, 2022

## Join us

> **[Jitsi Meet](https://meet.jit.si/PX4DeveloperCallWeekly)**
>
> Join a WebRTC video conference powered by the Jitsi Videobridge

## Agenda

- Community Announcement
- Community Q&A
- Project Updates
- General Discussions
- Weekly Overview
- High priority queue
- Release

## 📢 Community Announcement

* * *

### 🎉 THANK YOU for 35 applications to the CFP!

- Ramon

## 🧑‍🤝‍🧑 Community Q&A (No deep technical discussions)

* * *

### Q.1 : Servo Control by UAVCAN - Dave

- Currently in the Doc, it’s mentioned that Servos are not supported.
- Is there a support upcoming in the roadmap?
- [UAVCAN servo support?](https://discuss.px4.io/t/uavcan-servo-support/27110)
- There’s UAVCAN call at 2pm
- Check the **Description** Language listed (directory under UAVCAN)

### Q.2 : Response delay when using MAVROS (Python → C++) - Patrick

- Using coaxial quadcopter w/ tilting mechanism, controlled by parameters!
- Using Telemetry Module, baudrate unknown.
- Experiencing ~10 sec delay when using Python API
- Answers
  - MAVROS Python itself doesn’t have much delay - Ben
  - Could be that telemetry is the problem, 921600 is usually good baud - Jay
  - Check the exact delay (by Python code)
  - Can increase parameter update checking rate

### Q.3 : Actuators : How to send PWM without arming - Safy

- Currently using Offboard Actuator control
- Want to release a payload (servo control), without arming the vehicle
- Answers
  - For Fixed Wing, it is possible to move control surfaces without arming
  - Check Fixed Wing Mixer, may need customized mixer
  - COM\_PREARM\_MODE parameter
  - [Prearm, Arm, Disarm Configuration | PX4 User Guide (v1.12)](https://docs.px4.io/v1.12/en/advanced_config/prearm_arm_disarm.html#arming-sequence-pre-arm-mode-safety-button) \<\< Check it out!

### Q.4 : When RC receiver powers up after vehicle powers up, it doesn’t get recognized - Safy

- Using v1.13 alpha version (from a month ago)
- Answers
  - Can have race conditions where power-up order can change how the RC protocol is guessed
  - RC input drivers will be separated, and remove auto-guessing eventually
  - Chris will put a detailed answer in comment section
  - Using MAVLink message for remote control is just not as good as RC (Due to telemetry limitations) - Chris
  - Even with IP radio (WiFi), MAVLink protocol overhead will limit the rate - Ben

### Q.5 : Sensors Redundancy & RAM usage - Safy

- New versions of Flight controllers advertise high CPU / RAM capability. But when do we need it?
- Trying to use SLAM
- Answer
  - For Multi-EKF, H7 or F7 processors will be needed - David
  - RAM size varies a lot
  - Check Jenkins’ build, for RAM usage percentage.
  - Original 1 MB RAM v2 hardware
  - Better to stick to higher capability CPUs!
  - Good for encryption & secure bootloading

## 👷‍♀️ Project Updates

* * *

### P.1 :

## 🤔 General Discussions

* * *

### D.0 : 1. Safe local coordinate manipulation by @tstastny

- 

### D.1 : Dubins Aircraft MAVLink Message by @tstastny

> **[Google Docs: Sign-in](https://accounts.google.com/v3/signin/identifier?continue=https%3A%2F%2Fdocs.google.com%2Fdocument%2Fd%2F18CDpSgL1j5-sSV6hj4FbS7FYCLAv8xj-fcbaUclOoTU%2Fedit&dsh=S-838032008%3A1774376494147973&followup=https%3A%2F%2Fdocs.google.com%2Fdocument%2Fd%2F18CDpSgL1j5-sSV6hj4FbS7FYCLAv8xj-fcbaUclOoTU%2Fedit&ltmpl=docs&osid=1&passive=1209600&service=wise&flowName=GlifWebSignIn&flowEntry=ServiceLogin&ifkv=AT1y2_VTMlcoF_bBX-dXveTk9FOFTtWPcNIh3apA6uMFBl7iRcylRTLQpUIsL6F8W9ibS0FLMR9DOA)**
>
> Access Google Docs with a personal Google account or Google Workspace account (for business use).

### D.2 :

## 📅 Weekly Overview

* * *

### 🐁 Github

> [Recently updated Issues / PRs in PX4-Autopilot Link](https://github.com/PX4/PX4-Autopilot/issues?q=sort%3Aupdated-desc)

#### Pull Requests

> Board Support

- [add Holybro KakuteH7 support by bkueng · Pull Request #19019 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/19019)

> Architecture

- [PX4 protected build pub by jlaitine · Pull Request #16931 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/16931)
- [[draft] drivers/pca9685\_pwm\_out switch to Dynamic Control Allocator by SalimTerryLi · Pull Request #19504 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/19504)
- [[WIP]: multi-EKF baro support and generalize sensors\_status (accel/baro/gyro/mag) by dagar · Pull Request #18065 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/18065)
- [https://github.com/PX4/PX4-Autopilot/pull/18318](https://github.com/PX4/PX4-Autopilot/pull/18318)
  - Currently the Auto modes are outputting trajectory\_setpoint uORB topic, and is getting confused with the same topic published from offboard control.
    - [Offboard trajectory\_setpoint conflict when in auto modes · Issue #18306 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/issues/18306)

  - Having 2 redundant topics can be problemetic - Jay
  - Currently only possible to land in offboard mode by setting offboard trajectory setpoint below the ground.
  - Intertwined with PX4 ROS comm
  - There’s Offboard Control message for MAVLink.
  - Suggestion : **Check the case of doing offboard via MAVLink** , and check why in ROS mode there’s an error.
  - Better to fix in higher-level!

> New Feature

- [MSP telemetry and OSD support by chris1seto · Pull Request #19515 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/19515)

> Convenience

- [Automate baro pressure coefficients tuning by bresch · Pull Request #19507 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/19507)

> Flight control

- [https://github.com/PX4/PX4-Autopilot/pull/18973](https://github.com/PX4/PX4-Autopilot/pull/18973)
- [FlightTaskAuto: remove \_land\_heading and instead directly set \_yaw\_setpoint (fixes weather vane landings) by sfuhrer · Pull Request #19510 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/19510)
- [[WIP]: fw\_pos\_control\_l1: landing speed for FW Landing and alternate min airspeed with flaps deployed by ryanjAA · Pull Request #16675 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/16675)
- [mc\_pos\_control: filter velocity before derivative and switch to AlphaFilter by dagar · Pull Request #19505 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/19505)

> Other

- [commander: Add prearm check for flight termination by julianoes · Pull Request #19419 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/19419)
- [add ability to disable board sensors by PonomarevDA · Pull Request #18550 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/18550)
- [Offboard separate trajectory\_setpoint topic by benjinne · Pull Request #18318 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/18318#discussion_r859850920)
- [RC not responding when vehicle is powered up before the RC · Issue #19541 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/issues/19541)

#### Issues

- [Some questions about mission mode issues? · Issue #19519 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/issues/19519)

> SITL

- [Unable to launch Custom Airframe (proprietary) on SITL. · Issue #19457 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/issues/19457)

### 💻 Slack

> General Updates

- MODAL-AI’s VOXL 2 Launch
  - [https://www.businesswire.com/news/home/20220425005133/en/ModalAI](https://www.businesswire.com/news/home/20220425005133/en/ModalAI)

> Issues

- [QGC\_v4.1.7 Not Support other languages? · Issue #10268 · mavlink/qgroundcontrol · GitHub](https://github.com/mavlink/qgroundcontrol/issues/10268)

> Questions

- [Setting PX4’s PWM Voltage level](https://px4.slack.com/archives/C0V533X4N/p1650885687342809)
- [How to check GPS heading being received](https://px4.slack.com/archives/C0V533X4N/p1650885821107229)
- [Planning a mission from a moving vehicle on fixed wing](https://px4.slack.com/archives/C0V533X4N/p1650852990392959)
- [Flying indoor in position mode with PX4flow without GPS](https://px4.slack.com/archives/C0V533X4N/p1650632360176189)

### ☎ Last Dev-Call

> [PX4 Dev Call: April 20, 2022](https://discuss.px4.io/t/px4-dev-call-april-20-2022/26970)

- BeiDou satellite network usage update - Tony

## ❗ High priority queue

* * *

Discussion based on : [https://github.com/orgs/PX4/projects/24](https://github.com/orgs/PX4/projects/24)

## 🌾 Release

* * *