# RPi-3 serial port problems

**URL:** <https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153>\
**Category:** General\
**Created:** [23 May 2020 17:58 UTC](https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153 "2020-05-23T17:58:09Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![warnert](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/warnert/32/108132_2.png) [@warnert](https://discourse.nodered.org/u/warnert)\
**Post date:** [23 May 2020 17:58 UTC](https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153/1 "2020-05-23T17:58:09Z")

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I had a setup running on a RPi-2 with sensors on the serial port, ttyAMA0. That worked.  
But it was a bit slow so I moved to a RPi-3. They used the ttyAMA0 port for bluetooth, so it is not free anymore.  
I found something about removing the port from BT, but that didn't work.  
I have a very simple test setup: a timestamp connected to serial out, and the a serial in to debug.  
I tried ttyS0 but that didn't work either. And there are problems with the baudrate as the clock is derived from the cpu clock and that varies.  
So I hooked up a FTDI232 to the usb to give me a ttyUSB0. I thought that should work. No. Oh btw, I did connect the rx to the tx on the FTDI as well as on the pi.  
Obvoiusly I am doing something wrong of forget something, but I don't know what.  
Or should I abandon the serial port altogether and hook my sensors to a ESP8266 and connect that to MQTT (what I also have running)?  
Oh and I run latest versions of all the software, although Raspbian without GUI.

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**Author:** ![warnert](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/warnert/32/108132_2.png) [@warnert](https://discourse.nodered.org/u/warnert)\
**Post date:** [23 May 2020 19:06 UTC](https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153/2 "2020-05-23T19:06:18Z")

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I checked again and I see the RX and the TX led on the FTDI232 flash when I trigger the timestamp.  
So I think the transmit portion works, only the receive does not do what I expect.

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**Author:** ![warnert](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/warnert/32/108132_2.png) [@warnert](https://discourse.nodered.org/u/warnert)\
**Post date:** [23 May 2020 20:49 UTC](https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153/3 "2020-05-23T20:49:20Z")

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Ok. One problem solved. On the serial-port properties section input the "split input" I had to set.  
For my test setup to a time-out. Or to \n but that I had to add to the output-section to indicate the end-of-packet.  
That solved the problem with the ttyUSB0.  
Still I don't like the fact that you cannot use AMA0 anymore. Would save me a device. And a USB-port.

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**Author:** ![edje11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/edje11/32/572_2.png) [@edje11](https://discourse.nodered.org/u/edje11)\
**Post date:** [23 May 2020 21:21 UTC](https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153/4 "2020-05-23T21:21:25Z")

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You can still use AMA0,

> **[Configuring The GPIO Serial Port On Raspbian Jessie and Stretch Including Pi...](https://spellfoundry.com/2016/05/29/configuring-gpio-serial-port-raspbian-jessie-including-pi-3-4/)**
>
> The Raspberry Pi GPIO serial port configuration has changed under Jessie / Stretch / Buster and also with the Raspberry PI 3 / 4. How to set it up.

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**Author:** ![warnert](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/warnert/32/108132_2.png) [@warnert](https://discourse.nodered.org/u/warnert)\
**Post date:** [24 May 2020 06:38 UTC](https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153/5 "2020-05-24T06:38:09Z")

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Thanks, that worked. So I'm back to AMA0.

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [7 June 2020 06:38 UTC](https://discourse.nodered.org/t/rpi-3-serial-port-problems/27153/6 "2020-06-07T06:38:16Z")

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