How many serial ports are on the Pi 3?





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How many serial ports are on the Pi 3? There is one on the GPIO pin that goes to ttyS0. Is there a separate one for USB? I have read somewhere about /dev/ttyUSB0. Is that a separate serial port?



Place mentioning ttyUSB0:
https://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi/setting-everything-up










share|improve this question































    3















    How many serial ports are on the Pi 3? There is one on the GPIO pin that goes to ttyS0. Is there a separate one for USB? I have read somewhere about /dev/ttyUSB0. Is that a separate serial port?



    Place mentioning ttyUSB0:
    https://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi/setting-everything-up










    share|improve this question



























      3












      3








      3








      How many serial ports are on the Pi 3? There is one on the GPIO pin that goes to ttyS0. Is there a separate one for USB? I have read somewhere about /dev/ttyUSB0. Is that a separate serial port?



      Place mentioning ttyUSB0:
      https://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi/setting-everything-up










      share|improve this question
















      How many serial ports are on the Pi 3? There is one on the GPIO pin that goes to ttyS0. Is there a separate one for USB? I have read somewhere about /dev/ttyUSB0. Is that a separate serial port?



      Place mentioning ttyUSB0:
      https://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi/setting-everything-up







      pi-3 serial






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited 15 hours ago









      Aurora0001

      5,39931533




      5,39931533










      asked yesterday









      bakalolobakalolo

      1659




      1659






















          2 Answers
          2






          active

          oldest

          votes


















          3














          The Pi has 2 serial ports, but only 1 is accessible - the other is connected to Bluetooth. (It is possible to switch ports in Device Tree.)



          See How do I make serial work on the Raspberry Pi3 , Pi3B+, PiZeroW for more detail.



          You can add additional ports with a USB-serial adapter.






          share|improve this answer


























          • Conscise answer (+1) but maybe just clarify that USB-serial adaptors are (depending on the driver etc.etc.) the ttyUSBn mentioned by the OP in the question?

            – Roger Jones
            15 hours ago





















          3














          Question



          How many serial ports are on the Rpi3



          Answer



          I have been playing with serial communication this couple of days. I googled and the found the following tutorial useful.



          Raspberry Pi Serial (UART) Tutorial - Roland Pelayo 2018jun22 17,305 Views



          I extracted what the author says below:




          Technically, the Raspberry Pi has two UARTs: PL011 UART and mini UART.
          However, you only have one pair of TXD and RXD pins to work with.



          The PL011 UART is the main UART for models without Bluetooth feature
          and is tied directly to the Linux console output. This means you can
          send Linux commands from your PC to the Raspberry Pi on this UART.



          On the other hand, the mini UART becomes the Linux console UART for
          models with Bluetooth like the Raspberry Pi 3 and Raspberry Pi Zero W.
          For these models, the PL011 UART is tied directly to the Bluetooth
          module.



          Whichever UART is assigned to the Linux console is accessible through
          /dev/serial0. Each UART can be accessed individually via /dev/ttyS0
          for the mini UART and /dev/ttyAMA0 for the PL011 UART.



          Generally, the PL011 UART is more reliable than the mini UART because
          the latter has smaller FIFOs , lacks flow control and has its baud
          rate reliant on the VPU clock speed.




          My experiment results



          I followed his instructions and have been doing experiments and found everything works as he suggests.



          I used to use four TXS0104 logical level converters to demux one UART channel into 4. I select one one of the four channels by enabling TXS0104 converter I want. It works smoothly, except you can not use more than one UART channel at the same time.



          I also tried the USB to TTL adapters for Rpi3B+ Raspbian version 2019Apr. I found both PL2302 and CH340 adapters can be detected without installed drivers.



          In other words, Raspbian version 2019apr already have Pl2303 and CH340 drivers installed.



          I also tried the CP2102 USB to TTL adapters, but many CP2102 modules are sadly not compatible to Win10 and ESP8266-12. I have not tried it on Rpi.



          rpi3b+ usb ttl driver



          NXP SC16IS750 I2C/SPI to UART Module Not Recommended for Newbies



          SparkFun once sold a NXP I2C/SPI to UART module. I thought it too good to be true to be able to have as many UART channels as I wanted. But then I found the datasheet has some "special features" which are perhaps OK for hackers to deal with, but too difficult for newbies to handle. I tried hard for a couple of days and gave up. SparkFun has now discontinued this module for a reason.



          The other modules AdaFruit are recommending are TXS/TXB0108 modules. I have been using TSX/TSB0104s for demultiplexing UART/I2C/SPI channels and found them OK, if not too greedy to entertain too many channels at the same time. Actually I found many I2C modules (including MCP23017) when grouped more than two, become unstable and difficult to troubleshoot. Perhaps I have not learnt all the tricks in fiddling the I2C pull up resistors. Anyway, trying just one is OK for newbies.



          TSX0104E



          References



          AdaFruit TXB0108 8-channel Bi-directional Logic Level Converter - $8.00



          TXB0108 Datasheet - TI



          TXS0104E Datasheet - TI



          Amazon SC16IS750 I2C/SPI to UART Module



          SparkFun SC16IS750 I2C/SPI-to-UART Module



          SC16IS750 I2C/SPI to UART Datasheet - NXP



          The 6 Best Arduino GPS Modules - Josh Darling 2019jan






          share|improve this answer


























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            2 Answers
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            2 Answers
            2






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            3














            The Pi has 2 serial ports, but only 1 is accessible - the other is connected to Bluetooth. (It is possible to switch ports in Device Tree.)



            See How do I make serial work on the Raspberry Pi3 , Pi3B+, PiZeroW for more detail.



            You can add additional ports with a USB-serial adapter.






            share|improve this answer


























            • Conscise answer (+1) but maybe just clarify that USB-serial adaptors are (depending on the driver etc.etc.) the ttyUSBn mentioned by the OP in the question?

              – Roger Jones
              15 hours ago


















            3














            The Pi has 2 serial ports, but only 1 is accessible - the other is connected to Bluetooth. (It is possible to switch ports in Device Tree.)



            See How do I make serial work on the Raspberry Pi3 , Pi3B+, PiZeroW for more detail.



            You can add additional ports with a USB-serial adapter.






            share|improve this answer


























            • Conscise answer (+1) but maybe just clarify that USB-serial adaptors are (depending on the driver etc.etc.) the ttyUSBn mentioned by the OP in the question?

              – Roger Jones
              15 hours ago
















            3












            3








            3







            The Pi has 2 serial ports, but only 1 is accessible - the other is connected to Bluetooth. (It is possible to switch ports in Device Tree.)



            See How do I make serial work on the Raspberry Pi3 , Pi3B+, PiZeroW for more detail.



            You can add additional ports with a USB-serial adapter.






            share|improve this answer















            The Pi has 2 serial ports, but only 1 is accessible - the other is connected to Bluetooth. (It is possible to switch ports in Device Tree.)



            See How do I make serial work on the Raspberry Pi3 , Pi3B+, PiZeroW for more detail.



            You can add additional ports with a USB-serial adapter.







            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited 22 hours ago

























            answered 22 hours ago









            MilliwaysMilliways

            30.8k1357117




            30.8k1357117













            • Conscise answer (+1) but maybe just clarify that USB-serial adaptors are (depending on the driver etc.etc.) the ttyUSBn mentioned by the OP in the question?

              – Roger Jones
              15 hours ago





















            • Conscise answer (+1) but maybe just clarify that USB-serial adaptors are (depending on the driver etc.etc.) the ttyUSBn mentioned by the OP in the question?

              – Roger Jones
              15 hours ago



















            Conscise answer (+1) but maybe just clarify that USB-serial adaptors are (depending on the driver etc.etc.) the ttyUSBn mentioned by the OP in the question?

            – Roger Jones
            15 hours ago







            Conscise answer (+1) but maybe just clarify that USB-serial adaptors are (depending on the driver etc.etc.) the ttyUSBn mentioned by the OP in the question?

            – Roger Jones
            15 hours ago















            3














            Question



            How many serial ports are on the Rpi3



            Answer



            I have been playing with serial communication this couple of days. I googled and the found the following tutorial useful.



            Raspberry Pi Serial (UART) Tutorial - Roland Pelayo 2018jun22 17,305 Views



            I extracted what the author says below:




            Technically, the Raspberry Pi has two UARTs: PL011 UART and mini UART.
            However, you only have one pair of TXD and RXD pins to work with.



            The PL011 UART is the main UART for models without Bluetooth feature
            and is tied directly to the Linux console output. This means you can
            send Linux commands from your PC to the Raspberry Pi on this UART.



            On the other hand, the mini UART becomes the Linux console UART for
            models with Bluetooth like the Raspberry Pi 3 and Raspberry Pi Zero W.
            For these models, the PL011 UART is tied directly to the Bluetooth
            module.



            Whichever UART is assigned to the Linux console is accessible through
            /dev/serial0. Each UART can be accessed individually via /dev/ttyS0
            for the mini UART and /dev/ttyAMA0 for the PL011 UART.



            Generally, the PL011 UART is more reliable than the mini UART because
            the latter has smaller FIFOs , lacks flow control and has its baud
            rate reliant on the VPU clock speed.




            My experiment results



            I followed his instructions and have been doing experiments and found everything works as he suggests.



            I used to use four TXS0104 logical level converters to demux one UART channel into 4. I select one one of the four channels by enabling TXS0104 converter I want. It works smoothly, except you can not use more than one UART channel at the same time.



            I also tried the USB to TTL adapters for Rpi3B+ Raspbian version 2019Apr. I found both PL2302 and CH340 adapters can be detected without installed drivers.



            In other words, Raspbian version 2019apr already have Pl2303 and CH340 drivers installed.



            I also tried the CP2102 USB to TTL adapters, but many CP2102 modules are sadly not compatible to Win10 and ESP8266-12. I have not tried it on Rpi.



            rpi3b+ usb ttl driver



            NXP SC16IS750 I2C/SPI to UART Module Not Recommended for Newbies



            SparkFun once sold a NXP I2C/SPI to UART module. I thought it too good to be true to be able to have as many UART channels as I wanted. But then I found the datasheet has some "special features" which are perhaps OK for hackers to deal with, but too difficult for newbies to handle. I tried hard for a couple of days and gave up. SparkFun has now discontinued this module for a reason.



            The other modules AdaFruit are recommending are TXS/TXB0108 modules. I have been using TSX/TSB0104s for demultiplexing UART/I2C/SPI channels and found them OK, if not too greedy to entertain too many channels at the same time. Actually I found many I2C modules (including MCP23017) when grouped more than two, become unstable and difficult to troubleshoot. Perhaps I have not learnt all the tricks in fiddling the I2C pull up resistors. Anyway, trying just one is OK for newbies.



            TSX0104E



            References



            AdaFruit TXB0108 8-channel Bi-directional Logic Level Converter - $8.00



            TXB0108 Datasheet - TI



            TXS0104E Datasheet - TI



            Amazon SC16IS750 I2C/SPI to UART Module



            SparkFun SC16IS750 I2C/SPI-to-UART Module



            SC16IS750 I2C/SPI to UART Datasheet - NXP



            The 6 Best Arduino GPS Modules - Josh Darling 2019jan






            share|improve this answer






























              3














              Question



              How many serial ports are on the Rpi3



              Answer



              I have been playing with serial communication this couple of days. I googled and the found the following tutorial useful.



              Raspberry Pi Serial (UART) Tutorial - Roland Pelayo 2018jun22 17,305 Views



              I extracted what the author says below:




              Technically, the Raspberry Pi has two UARTs: PL011 UART and mini UART.
              However, you only have one pair of TXD and RXD pins to work with.



              The PL011 UART is the main UART for models without Bluetooth feature
              and is tied directly to the Linux console output. This means you can
              send Linux commands from your PC to the Raspberry Pi on this UART.



              On the other hand, the mini UART becomes the Linux console UART for
              models with Bluetooth like the Raspberry Pi 3 and Raspberry Pi Zero W.
              For these models, the PL011 UART is tied directly to the Bluetooth
              module.



              Whichever UART is assigned to the Linux console is accessible through
              /dev/serial0. Each UART can be accessed individually via /dev/ttyS0
              for the mini UART and /dev/ttyAMA0 for the PL011 UART.



              Generally, the PL011 UART is more reliable than the mini UART because
              the latter has smaller FIFOs , lacks flow control and has its baud
              rate reliant on the VPU clock speed.




              My experiment results



              I followed his instructions and have been doing experiments and found everything works as he suggests.



              I used to use four TXS0104 logical level converters to demux one UART channel into 4. I select one one of the four channels by enabling TXS0104 converter I want. It works smoothly, except you can not use more than one UART channel at the same time.



              I also tried the USB to TTL adapters for Rpi3B+ Raspbian version 2019Apr. I found both PL2302 and CH340 adapters can be detected without installed drivers.



              In other words, Raspbian version 2019apr already have Pl2303 and CH340 drivers installed.



              I also tried the CP2102 USB to TTL adapters, but many CP2102 modules are sadly not compatible to Win10 and ESP8266-12. I have not tried it on Rpi.



              rpi3b+ usb ttl driver



              NXP SC16IS750 I2C/SPI to UART Module Not Recommended for Newbies



              SparkFun once sold a NXP I2C/SPI to UART module. I thought it too good to be true to be able to have as many UART channels as I wanted. But then I found the datasheet has some "special features" which are perhaps OK for hackers to deal with, but too difficult for newbies to handle. I tried hard for a couple of days and gave up. SparkFun has now discontinued this module for a reason.



              The other modules AdaFruit are recommending are TXS/TXB0108 modules. I have been using TSX/TSB0104s for demultiplexing UART/I2C/SPI channels and found them OK, if not too greedy to entertain too many channels at the same time. Actually I found many I2C modules (including MCP23017) when grouped more than two, become unstable and difficult to troubleshoot. Perhaps I have not learnt all the tricks in fiddling the I2C pull up resistors. Anyway, trying just one is OK for newbies.



              TSX0104E



              References



              AdaFruit TXB0108 8-channel Bi-directional Logic Level Converter - $8.00



              TXB0108 Datasheet - TI



              TXS0104E Datasheet - TI



              Amazon SC16IS750 I2C/SPI to UART Module



              SparkFun SC16IS750 I2C/SPI-to-UART Module



              SC16IS750 I2C/SPI to UART Datasheet - NXP



              The 6 Best Arduino GPS Modules - Josh Darling 2019jan






              share|improve this answer




























                3












                3








                3







                Question



                How many serial ports are on the Rpi3



                Answer



                I have been playing with serial communication this couple of days. I googled and the found the following tutorial useful.



                Raspberry Pi Serial (UART) Tutorial - Roland Pelayo 2018jun22 17,305 Views



                I extracted what the author says below:




                Technically, the Raspberry Pi has two UARTs: PL011 UART and mini UART.
                However, you only have one pair of TXD and RXD pins to work with.



                The PL011 UART is the main UART for models without Bluetooth feature
                and is tied directly to the Linux console output. This means you can
                send Linux commands from your PC to the Raspberry Pi on this UART.



                On the other hand, the mini UART becomes the Linux console UART for
                models with Bluetooth like the Raspberry Pi 3 and Raspberry Pi Zero W.
                For these models, the PL011 UART is tied directly to the Bluetooth
                module.



                Whichever UART is assigned to the Linux console is accessible through
                /dev/serial0. Each UART can be accessed individually via /dev/ttyS0
                for the mini UART and /dev/ttyAMA0 for the PL011 UART.



                Generally, the PL011 UART is more reliable than the mini UART because
                the latter has smaller FIFOs , lacks flow control and has its baud
                rate reliant on the VPU clock speed.




                My experiment results



                I followed his instructions and have been doing experiments and found everything works as he suggests.



                I used to use four TXS0104 logical level converters to demux one UART channel into 4. I select one one of the four channels by enabling TXS0104 converter I want. It works smoothly, except you can not use more than one UART channel at the same time.



                I also tried the USB to TTL adapters for Rpi3B+ Raspbian version 2019Apr. I found both PL2302 and CH340 adapters can be detected without installed drivers.



                In other words, Raspbian version 2019apr already have Pl2303 and CH340 drivers installed.



                I also tried the CP2102 USB to TTL adapters, but many CP2102 modules are sadly not compatible to Win10 and ESP8266-12. I have not tried it on Rpi.



                rpi3b+ usb ttl driver



                NXP SC16IS750 I2C/SPI to UART Module Not Recommended for Newbies



                SparkFun once sold a NXP I2C/SPI to UART module. I thought it too good to be true to be able to have as many UART channels as I wanted. But then I found the datasheet has some "special features" which are perhaps OK for hackers to deal with, but too difficult for newbies to handle. I tried hard for a couple of days and gave up. SparkFun has now discontinued this module for a reason.



                The other modules AdaFruit are recommending are TXS/TXB0108 modules. I have been using TSX/TSB0104s for demultiplexing UART/I2C/SPI channels and found them OK, if not too greedy to entertain too many channels at the same time. Actually I found many I2C modules (including MCP23017) when grouped more than two, become unstable and difficult to troubleshoot. Perhaps I have not learnt all the tricks in fiddling the I2C pull up resistors. Anyway, trying just one is OK for newbies.



                TSX0104E



                References



                AdaFruit TXB0108 8-channel Bi-directional Logic Level Converter - $8.00



                TXB0108 Datasheet - TI



                TXS0104E Datasheet - TI



                Amazon SC16IS750 I2C/SPI to UART Module



                SparkFun SC16IS750 I2C/SPI-to-UART Module



                SC16IS750 I2C/SPI to UART Datasheet - NXP



                The 6 Best Arduino GPS Modules - Josh Darling 2019jan






                share|improve this answer















                Question



                How many serial ports are on the Rpi3



                Answer



                I have been playing with serial communication this couple of days. I googled and the found the following tutorial useful.



                Raspberry Pi Serial (UART) Tutorial - Roland Pelayo 2018jun22 17,305 Views



                I extracted what the author says below:




                Technically, the Raspberry Pi has two UARTs: PL011 UART and mini UART.
                However, you only have one pair of TXD and RXD pins to work with.



                The PL011 UART is the main UART for models without Bluetooth feature
                and is tied directly to the Linux console output. This means you can
                send Linux commands from your PC to the Raspberry Pi on this UART.



                On the other hand, the mini UART becomes the Linux console UART for
                models with Bluetooth like the Raspberry Pi 3 and Raspberry Pi Zero W.
                For these models, the PL011 UART is tied directly to the Bluetooth
                module.



                Whichever UART is assigned to the Linux console is accessible through
                /dev/serial0. Each UART can be accessed individually via /dev/ttyS0
                for the mini UART and /dev/ttyAMA0 for the PL011 UART.



                Generally, the PL011 UART is more reliable than the mini UART because
                the latter has smaller FIFOs , lacks flow control and has its baud
                rate reliant on the VPU clock speed.




                My experiment results



                I followed his instructions and have been doing experiments and found everything works as he suggests.



                I used to use four TXS0104 logical level converters to demux one UART channel into 4. I select one one of the four channels by enabling TXS0104 converter I want. It works smoothly, except you can not use more than one UART channel at the same time.



                I also tried the USB to TTL adapters for Rpi3B+ Raspbian version 2019Apr. I found both PL2302 and CH340 adapters can be detected without installed drivers.



                In other words, Raspbian version 2019apr already have Pl2303 and CH340 drivers installed.



                I also tried the CP2102 USB to TTL adapters, but many CP2102 modules are sadly not compatible to Win10 and ESP8266-12. I have not tried it on Rpi.



                rpi3b+ usb ttl driver



                NXP SC16IS750 I2C/SPI to UART Module Not Recommended for Newbies



                SparkFun once sold a NXP I2C/SPI to UART module. I thought it too good to be true to be able to have as many UART channels as I wanted. But then I found the datasheet has some "special features" which are perhaps OK for hackers to deal with, but too difficult for newbies to handle. I tried hard for a couple of days and gave up. SparkFun has now discontinued this module for a reason.



                The other modules AdaFruit are recommending are TXS/TXB0108 modules. I have been using TSX/TSB0104s for demultiplexing UART/I2C/SPI channels and found them OK, if not too greedy to entertain too many channels at the same time. Actually I found many I2C modules (including MCP23017) when grouped more than two, become unstable and difficult to troubleshoot. Perhaps I have not learnt all the tricks in fiddling the I2C pull up resistors. Anyway, trying just one is OK for newbies.



                TSX0104E



                References



                AdaFruit TXB0108 8-channel Bi-directional Logic Level Converter - $8.00



                TXB0108 Datasheet - TI



                TXS0104E Datasheet - TI



                Amazon SC16IS750 I2C/SPI to UART Module



                SparkFun SC16IS750 I2C/SPI-to-UART Module



                SC16IS750 I2C/SPI to UART Datasheet - NXP



                The 6 Best Arduino GPS Modules - Josh Darling 2019jan







                share|improve this answer














                share|improve this answer



                share|improve this answer








                edited 18 hours ago

























                answered 23 hours ago









                tlfong01tlfong01

                807312




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