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abelectronicsuk
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Pi Zero W UART and bluetooth

Tue Feb 28, 2017 10:37 am

Can anyone at RPI confirm if the new Pi Zero W uses the same soft UART to the GPIO headers as the Pi 3 or is the original hardware UART still connected to the GPIO ?

jamesh
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Re: Pi Zero W UART and bluetooth

Tue Feb 28, 2017 2:54 pm

abelectronicsuk wrote:Can anyone at RPI confirm if the new Pi Zero W uses the same soft UART to the GPIO headers as the Pi 3 or is the original hardware UART still connected to the GPIO ?
It's effectively the same as the Pi3 (note, both are HW UARTS on there too) with a minor but useful difference in the on the Zero, the UART to the BT module now has the HW flow control wired up so can go much faster. So BT on the ZeroW is 'better' than on the Pi3.

AMA0 goes to the BT, TTY0 for console on the GPIO pins.
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stderr
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Re: Pi Zero W UART and bluetooth

Tue Feb 28, 2017 4:09 pm

jamesh wrote:So BT on the ZeroW is 'better' than on the Pi3.
I have a pi3 and I've never used the bluetooth or the wifi. I hope that the original zero is still produced and that serious effort is made to catch up to demand.

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abelectronicsuk
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Re: Pi Zero W UART and bluetooth

Tue Feb 28, 2017 6:58 pm

jamesh wrote:
abelectronicsuk wrote:Can anyone at RPI confirm if the new Pi Zero W uses the same soft UART to the GPIO headers as the Pi 3 or is the original hardware UART still connected to the GPIO ?
It's effectively the same as the Pi3 (note, both are HW UARTS on there too) with a minor but useful difference in the on the Zero, the UART to the BT module now has the HW flow control wired up so can go much faster. So BT on the ZeroW is 'better' than on the Pi3.

AMA0 goes to the BT, TTY0 for console on the GPIO pins.
Thank you for the info. With a HW uart on the GPIO it shouldnt change the baud rate like the Pi 3 does without fixing the CPU speed.

I have a barcode scanner project currently using a Pi Zero with external wifi card which uses the GPIO uart at 115200 to capture data from the laser module and the new board with onboard wifi should save some space in the case :)

dgordon42
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Re: Pi Zero W UART and bluetooth

Tue Feb 28, 2017 7:00 pm

jamesh wrote:AMA0 goes to the BT, TTY0 for console on the GPIO pins.
Previously it was ttyS0 on the Pi 3B. Has the device name changed, or is this a typo?

Also, can you confirm that the "serial0" alias will still work on the Zero W.

Kudos on the new model Pi, by the way.

Thanks,
Dave.

dgordon42
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Re: Pi Zero W UART and bluetooth

Tue Feb 28, 2017 7:11 pm

abelectronicsuk wrote:With a HW uart on the GPIO it shouldnt change the baud rate like the Pi 3 does without fixing the CPU speed.
Both of the UART's on the Pi 3B are hardware, it's the clock into the ttyS0 UART that changes.
I believe that the Zero W will still need "enable_uart=1" in '/boot/config.txt' to stabilize that clock, though it would be nice to hear it from the horses mouth.

Dave.

jamesh
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Re: Pi Zero W UART and bluetooth

Wed Mar 01, 2017 10:08 am

dgordon42 wrote:
jamesh wrote:AMA0 goes to the BT, TTY0 for console on the GPIO pins.
Previously it was ttyS0 on the Pi 3B. Has the device name changed, or is this a typo?

Also, can you confirm that the "serial0" alias will still work on the Zero W.

Kudos on the new model Pi, by the way.

Thanks,
Dave.
Typo I think. Not sure about the alias, but everything should work the same as on the B I believe.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
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jamesh
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Re: Pi Zero W UART and bluetooth

Wed Mar 01, 2017 10:09 am

stderr wrote:
jamesh wrote:So BT on the ZeroW is 'better' than on the Pi3.
I have a pi3 and I've never used the bluetooth or the wifi. I hope that the original zero is still produced and that serious effort is made to catch up to demand.
It will be produced, but I don't expect the one limit will be lifted in the near future. The margins are just too small, and we cannot have one person buying them all.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Please direct all questions to the forum, I do not do support via PM.

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