Question about UART's

Racing Quads, Self-builds & FPV
1

I have a question about UART’s. I have a GPS to wire up. On my fc I have 3 UART’s with tx and rx pads. I also have JST-SH sockets for camera, LED/buzzer board and SBUS receiver which are all being used. I have nothing soldered to the UART pads currently. Does that mean all my UART’s are free to use still or are the JST-SH sockets just another way to connect to the UART’s? Below is the fc I’m using

Screenshot_20210516-181354_Acrobat for Samsung
Screenshot_20210516-181354_Acrobat for Samsung1440×3088 627 KB

2

This.

But the camera and led’s/buzzer won’t use a uart

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3

Thanks for quick reply Karl :+1:t2: So that means my SBUS receiver is using a UART but the other 2 are free to use?

4

I reckon sbus is uart 2 or 4 maybe? So no pad for it as a uart as its inverted.

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5

This is my ports tab in Betaflight

20210516_183323
20210516_1833234000×3000 3.38 MB

But is was preconfigured when I got my quad. Like I say I have nothing soldered to the pads currently. Am I able to use any of these for my gps?

6

Looks like you have to use uart 1. You may have to remove the wire from the esc to the fc marked telemetry I think. No one uses it.

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7

Looks like a neat stack. uart 1 can be free, uart 3 for tramp (vtx setting control) and uart 6 is your rx.

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8

I will add one point though. I do like mmcx antenna connectors, but they can be picky.
If the antenna connector on the antenna is out of mechanical tolerance, it can move side to side or up and down, causing video signal loss. Sort of like a loose fit.

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9

Cheers Karl :+1:t2: I don’t seem to have a wire marked Telemetry? Between the fc and esc board I have a 7 pin JST-SH socket. They are labelled GRD, Batt, M1, M2, M3, M4 and CUR ? Do you think I can just use UART1 without having to remove a wire and just reassign the UART in Betaflight?

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10

Yep.

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11

Ah ok I will keep a good eye out for that thanks mate :+1:t2: What kind of connection are you using for your antenna?

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12

On my thfs and 5" its a ufl. The 7" is mmcx. But a nice tight fit antenna wise.

I only mention it because a while back I had a cheap antenna on a good vtx. But it wobbled. With the vibes of the quad, the video cut out 50m away.

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13

I’ll definitely keep an eye out on that then cheers. I have just fitted a new pig tail (mmcx to sma) for my antenna. It seems like a nice snug fit so far.
I have just reassigned UART 1 to gps so will solder it up and check it works cheers man :+1:t2:

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14

Update: Worked a treat thanks Karl @notveryprettyboy :+1:t2:
Out of curiosity what determines the GPS protocol used? The GPS unit itself or the fc being used?

15

I think its betaflight. I think most gps pucks are capable of nmea and ublox. But thats about as far as my knowledge goes with them.

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16

Ah cool thanks mate :+1:t2:

17

You can set the protocol in betaflight. You can also change the number of sats needed before arming is permitted, which I reduced to the minimum because I was waiting soooooo long for it to get a fix