[solved] flow brekboard on pixhawk4

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zhanghaijason
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[solved] flow brekboard on pixhawk4

Post by zhanghaijason » Fri Jul 03, 2020 10:47 pm

Hello,
I am trying to use the flow breakout board on pixhawk4. However, I found a problem. When I don't connect the battery to the drone, only with the USB cable to pixhawk 4, I can see the output of the flow breakout board in Qgroundcontrol, pretty good. However, when I plug in the battery. The flow breakout board connection was gone. The quality of the flow in Qgoundcontrol is vibrating between 0 and 255, making it impossible to use. Do you have any suggestions how to solve this? Thanks!



kimberly
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Re: flow brekboard on pixhawk4

Post by kimberly » Mon Jul 06, 2020 8:07 am

We are a bit low staffed at the office due to the holidays. I haven't worked myself with the flow-breakout board myself, but it indeed seems like an obvious power supply problem. Have you looked at the specifications on the storepage and are you sure it is constantly supplied between 3 and 5V

zhanghaijason
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Posts: 52
Joined: Fri Jul 28, 2017 9:07 pm

Re: flow brekboard on pixhawk4

Post by zhanghaijason » Mon Jul 06, 2020 5:16 pm

Hi Thanks for your reply. I checked that the VCC from pixhawk 4 SPI is even a little higher when using battery than USB power only. It is really strange since when I only use the USB to power the pixhawk 4 (pixhawk 4 SPI powers flow breakout board), flow breakout board works well. But when using the battery and to power pixhawk 4, the VCC from pixhawk 4 SPI is even higher (5.01v vs about 4.9v with USB power only). I will resolder everything today and to see if it still behaves like this.

zhanghaijason
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Posts: 52
Joined: Fri Jul 28, 2017 9:07 pm

Re: flow brekboard on pixhawk4

Post by zhanghaijason » Mon Jul 06, 2020 9:17 pm

kimberly wrote:
Mon Jul 06, 2020 8:07 am
We are a bit low staffed at the office due to the holidays. I haven't worked myself with the flow-breakout board myself, but it indeed seems like an obvious power supply problem. Have you looked at the specifications on the storepage and are you sure it is constantly supplied between 3 and 5V
Hi Kim,
Somehow I fixed the problem. But I cannot figure out why. What I did is just changed a connector of the VCC. But I don't think it makes sense a connector can cause this disconnection when using battery+usb power method. (While USB only power method is working well). Also, before I changed the connector, if using battery+usb, when I measure the voltage between VCC and GROUND, the flow breakout board can work again.

kimberly
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Re: flow brekboard on pixhawk4

Post by kimberly » Tue Jul 07, 2020 10:27 am

I'm kind of in the dark about this one itself. I wouldn't expect that the 5.01V would be even a problem at all. Once the rest is back I will mention this forum post and see if we can investigate this further.

Until then, at least I'm happy you were able to fix your problem.

zhanghaijason
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Posts: 52
Joined: Fri Jul 28, 2017 9:07 pm

Re: flow brekboard on pixhawk4

Post by zhanghaijason » Wed Jul 08, 2020 10:12 pm

kimberly wrote:
Tue Jul 07, 2020 10:27 am
I'm kind of in the dark about this one itself. I wouldn't expect that the 5.01V would be even a problem at all. Once the rest is back I will mention this forum post and see if we can investigate this further.

Until then, at least I'm happy you were able to fix your problem.
Unfortunately, It doesn't work again. I also tried using battery only, still no luck.I have no idea how to fix it now.

zhanghaijason
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Posts: 52
Joined: Fri Jul 28, 2017 9:07 pm

Re: flow brekboard on pixhawk4

Post by zhanghaijason » Thu Jul 09, 2020 5:09 am

zhanghaijason wrote:
Wed Jul 08, 2020 10:12 pm
kimberly wrote:
Tue Jul 07, 2020 10:27 am
I'm kind of in the dark about this one itself. I wouldn't expect that the 5.01V would be even a problem at all. Once the rest is back I will mention this forum post and see if we can investigate this further.

Until then, at least I'm happy you were able to fix your problem.
Unfortunately, It doesn't work again. I also tried using battery only, still no luck.I have no idea how to fix it now. And the voltage with battery +USB is more than 5.1V VS with USB only 4.8V

kimberly
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Re: flow brekboard on pixhawk4

Post by kimberly » Thu Jul 09, 2020 8:57 am

Ah oke too bad. How much V does the battery provide? It might have been too much and maybe it broke...

Do you maybe a different board you can try it on to see if it has not burned? Like here in the tutorial: https://www.bitcraze.io/documentation/t ... -breakout/

I can't not help you out much with these since the ones who know the most about this are not currently at the office. You could send an email to contact@bitcraze.io so that we can talk about if it is broken or not and if replacement is necessary.

zhanghaijason
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Posts: 52
Joined: Fri Jul 28, 2017 9:07 pm

Re: flow brekboard on pixhawk4

Post by zhanghaijason » Wed Jul 15, 2020 6:53 am

kimberly wrote:
Thu Jul 09, 2020 8:57 am
Ah oke too bad. How much V does the battery provide? It might have been too much and maybe it broke...

Do you maybe a different board you can try it on to see if it has not burned? Like here in the tutorial: https://www.bitcraze.io/documentation/t ... -breakout/

I can't not help you out much with these since the ones who know the most about this are not currently at the office. You could send an email to contact@bitcraze.io so that we can talk about if it is broken or not and if replacement is necessary.
Hi Kim,
Somehow I figured it out. The reason is still the VCC. Even the pixhawk 4 claims to output 5V, but it is 5.1V on mine as I said before. Then I used a 3.3V voltage regulator to power the VCC. Now everything works. So, I think PMW3901 should be strictly powered under 5V.

kimberly
Bitcraze
Posts: 456
Joined: Fri Jul 06, 2018 11:13 am

Re: flow brekboard on pixhawk4

Post by kimberly » Wed Jul 15, 2020 7:37 am

Alright good you figured it out! I didn't know that the flow-breakout board was so strict with that but apparently it is. Good to know!

Thanks for giving us an update.

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