VTX power up state

[Hwurzburg]

AndyP and I have had discussions about the power up state of VTX power when controlled by a GPIO.

Andy believes it should default to powered after boot to avoid users thinking something is wrong with the board (having not read the documentation on VTX power control)

My position is that its a safety issue (shoot down someone flying already on your channel...since you cant power the VTX off until boot completes and the user takes an action to power off) and a power issue (many VTX will overheat in the pits if on...user should power it on just before takeoff)

To avoid review conflicts, I have modified my review tools to adhere to Andy's position, but I think it worth discussing....I know my flying buddies in MultiGP racing agree with my view.

[peterbarker]

@andyp1per

[LupusTheCanine]

Defaulting to off in bootloader seems better.

Would it be possible to keep the state during reboot? Some VTX take a noticeable amount of time to boot.

[Hwurzburg]

Defaulting to off in bootloader seems better.

Would it be possible to keep the state during reboot? Some VTX take a noticeable amount of time to boot.

a user can easily elect to have it boot with power on by changing the relay parameter, it will always power up on boot then....user choice...or even the OEM's choice for the board....I just think the default should be off unless the OEM specifically demands it default to power on (and I would cahnge my review tools to mention this if we agree) or the user conciously elects to boot up with power applied

[Hwurzburg]

labeled for both devcalls so everyone gets an input

[andyp1per]

A user can easily elect to switch it off by default. There are many boards where there is no switch - its just on - so I don't buy the safety concern. Net-net people who care will set it up correctly, those who don' t at least get something that works without tearing their hair out - there are already too many bear traps in AP lets not create another one.

[timtuxworth]

I think @Hwurzburg is right. People need to read the manual.

[CraigElder]

I vote to defaulting to off and the user can turn it on at their discretion when they are certain it will not cause a problem.

[rmackay9]

I don't fly FPV but I think the danger of knocking out other pilot's video is a serious enough safety hazard that we should default the power to low-power.

Saying that though, normally when we have a disagreement in the dev team (or in our user community) we add an option bit to allow either behaviour. Then of course we're left with trying to decide what the default should be.

Re handling the support load issue:

1. we could try and "handle it through documentation" by putting it on the wiki. of course we struggle to get users to read the manual
2. we could add something to the startup series of text outputs to specify what the power mode of the VTX is in the hopes that the pilot might see it on the GCS

Of course we all want our community members to be happy so we could consider a poll on RC Groups or wherever FPV fliers are. Maybe Trappy should decide?

[Hwurzburg]

I don't fly FPV but I think the danger of knocking out other pilot's video is a serious enough safety hazard that we should default the power to low-power.

Saying that though, normally when we have a disagreement in the dev team (or in our user community) we add an option bit to allow either behaviour. Then of course we're left with trying to decide what the default should be.

Re handling the support load issue:

1. we could try and "handle it through documentation" by putting it on the wiki.  of course we struggle to get users to read the manual

2. we could add something to the startup series of text outputs to specify what the power mode of the VTX is in the hopes that the pilot might see it on the GCS

Of course we all want our community members to be happy so we could consider a poll on RC Groups or wherever FPV fliers are. Maybe Trappy should decide?

there already is a user option...the user can change the value of the RELAYx_DEFAULT...

I could add in my board review tool, that we always ask the OEM which he prefers as default bootup state if he has a GPIO control of VTX power....OFF, to avoid a user unknowingly having a potential safety/heat issue, or ON, to avoid having a user intentionally setting the power on after boot with the relay, OR changing his RELAYx_DEFAULT param.....this lets the OEM decide the behaviour he wants....so my review will include this....the VTX section of the readme will explain the user appropriately whichever the OEM finally decides as default....

[LupusTheCanine]

Ideally I would like OFF on cold boot and keep state during commanded reboot to avoid needlesly power cycling the VTX if it was powered on.

[andyp1per]

The safety argument is just a straw man. Who on earth is going to turn up to a flying field having never used his vehicle and board before and never having configured it, its just rubbish. I have certainly had to deal with people not getting power to their VTX's. This whole argument is pointless. I definitely agree that whatever the vendor wants should take priority over everything else. Also note that these GPIOs are quite frequently the wrong polarity - either because the board was done wrongly or the vendor provided the wrong information.

[Hwurzburg]

The safety argument is just a straw man. Who on earth is going to turn up to a flying field having never used his vehicle and board before and never having configured it, its just rubbish. I have certainly had to deal with people not getting power to their VTX's. This whole argument is pointless. I definitely agree that whatever the vendor wants should take priority over everything else. Also note that these GPIOs are quite frequently the wrong polarity - either because the board was done wrongly or the vendor provided the wrong information.

Your "rubbish" comment is "rubbish" itself, if you are going to get derogatory....I personally have been shot down several times at the field...once even during a MultiGP race....once by an experienced flyer WHILE he was asking if anyone was on his frequency (me!)!!!!...mostly by newer flyers not realizing that they were interfering as they powered up....