RTS/CTS（Request To Send/Clear To Send）握手协议，可以避免信道冲突导致的数据传输失败。. The full source code is listed as follows:I use Code blocks 20. 7 of Serial-HOWTO) CS8 : 8n1 (8bit,no parity,1 stopbit) CLOCAL : local connection, no modem contol CREAD : enable receiving characters */ newtio. petalinux is using 2019. All works fine expect the commissioning with the Thread Commissioning App. To get 9600 bps 8N1 with no flow control: Examples. 0. CRTSCTS return termios. 1. Using the command stty -F /dev/ttyS1 -a I can confirm that crtscts has been enabled. Example 2: UART1 in DCE mode. microcom -s 115200 /dev/ttyPS1. I typically use screen (1) to open a serial port with the command: sudo screen /dev/ttyUSB2 115200. Learn more about TeamsSerial communication is a commonly used method with which to exchange data between computers and peripheral devices. You signed in with another tab or window. > > Tested on S905X3 based board. Example 4-5. org> To: pkrasavin@imaqliq. 1 -chap modem #noauth -pap persist #maxfail 0 #holdoff 10 The passive option limits the number of (re)connection attempts. CRTSCTS : output hardware flow control (only used if the cable has all necessary lines. I can't get this working out of the box. Reported-by: Pho Tran <pho. 953090] vdd-3v3-slt: disabling [ 290. System administration command. 8. for output: when i do : int n = write (fd, "ATZ ", 4); it does not write immediately. c_iflag |= (IXOFF|IXON|IXANY); I assume that if I set both of UART1 and UART2 are Hardware flow control and baudrate is high (for eg. Read or write serial ports. Here is the output of the stty : root@localhost:~# stty -F /dev/ttyO0 speed 115200 baud; line = 0; -brkint -imaxbel. 4. Some versions of UNIX support hardware flow control using the CTS (Clear To Send) and RTS (Request To Send) signal lines. For example, connecting UART of I. RS232 +12V -12V is not TTL, avoid TTL devices these are for microcontrollers etc. Edit1: After you added your stty -a settings, I'll show you what differs between yours and mine. He used to manually respondxl2tpd is an implementation of the Layer 2 Tunneling Protocol as defined by RFC 2661 . Odd parity, else even. Yesterday, after enabling the FCM of 0xFF000024 directly with the devmem command, stty -F /dev/ttyPS1 crtscts. h> bit it gives me fatal error: sys/termios. it is used and works * add missing flow control pin configurations * change definition of MDMBUF to show it is an alias of CCAR_OFLOW * remove MDMBUF text in line with other flow control pinsSep 2 09:01:49 centos pppd[18018]: In file /etc/ppp/options. I have tried to set the correct serial settings using. h is squiggled with 'identifier "CRTSCTS" is undefined' but it can compile on gcc without any problems Default cStandard is incorrectly c11 instead of. Then, CTS/RTS was not effective, and I have been worried for a long time. The problem you are facing is a correct behaviour. If you need help enforcing a CRT order, you may want to get legal advice. The basic line discipline. Installed on Pi 3+ are asyn4-34, motor-R6-10-1, stream, ipac-2. Chapter 29. This option is not implemented on Windows. Reload to refresh your session. XCASE `crtscts' Enable RTS/CTS flow control. Avoid repeating the same code for rs485 twice. 2. The instructions to change the baud rate after returning from a device sleep state are as follows from the datasheet: I have one major problem in that I don't know what a 'break' code is in serial port communications. import serial import time ser = serial. 0. lecture materialsLinuxのC言語でシリアル通信に使うtermios構造体のc_cflag変数についてメモ。 数値はもしかしたら環境依存です。後に示すプログラムを実行して確認しました。 名前 値 説明 CBAUD 0x0000100F ボーレートのマスク。値は※1 CSIZE 0x00000030 データ長のマスク。値は※2 CSTO…patch to fix this. --help. For example, to view information that comes from the device behind the converter, you can use a command of the form: screen /dev/ttyUSB0 115200. h. Preprocessor macros do not have "scope" as such, they just define a piece of text that should replace the macro in the code. 下面将结合具体的代码说明如何设置这些参数。. 但如果每个工作站每次发送数据前都要执行该机制，则会导致过多的RTS帧占用信道带宽。. Provide details and share your research! But avoid. 11 2. vim works fine on the first invocation on a remote Windows host, but further use leads to my terminal getting messed up. 1. Shell ("stty -F " & mConnuri & " " & mPortspeed & " cs8 -parenb -cstopb -crtscts", Arh, Response, Error) But the other day we upgraded to Android 12. PC ( usually, DTE device): PC_UART_CTS ----INPUT; PC_UART_RTS---OUTPUT. Certified Rehabilitation Technology Supplier. The device. Specify an initialization timeout. 建议使用缺省值。. sudo cat /dev/ttyUSBPort1. 3. tty. API documentation for the Rust `CRTSCTS` constant in crate `libc`. h> ). Parity enable. @@ -828,7 +833,7 @@ static void sc16is7xx_set_mctrl (struct uart_port *port, unsigned int mctrl) + to disable CRTSCTS from now on. This can be verified by the command. Example 4-2. When you try to write to the UART output buffer it, probably, is full and application temporarily stops running and waits until some buffer space becomes available. See the xterm man page. 14 (but can move to 4. This is probably just what you expect. I'm ssh ing into the ubuntu system, if that matters. Then, CTS/RTS was not effective, and I have been worried for a long time. 長いオプションに必須の引数は短いオプションにも必須です。. If you're not using RTS/CTS, there's also the ixon setting that enables XON/XOFF flow control, but you may not want that. From: Pavel Krasavin <pkrasavin@imaqliq. In case i put VTIME to 0 then read blocks forever. To disable RTS/CTS hardware flow control on a serial port using the stty command, you can use the -crtscts option (including the hyphen). c_iflag |= (IXOFF|IXON|IXANY); I assume that if I set both of UART1 and UART2 are Hardware flow control and baudrate is high (for eg. c: uart 通信のテストプログラム. May 21, 2015 at 15:21. Working with QNX Momentics IDE. ExplanationThe CRTSCTS is (not in POSIX) Enable RTS/CTS (hardware) flow control. hello world wrote 4 bytes number of bytes read is 0 read error:: Success 0 0 0 0 0 0 0 0 0 0. c:38: error: `CRTSCTS' undeclared (first use in this function) >> >> CRTSCTS is defined in bits/termios. h instead of termios. c_cflag |= CRTSCTS. stty -F /dev/tty0 1000000 raw clocal -hupcl -echoIn the mode, CTS is INPUT, RTS is OUTPUT. This is almost never what. CRTSCTS (not in POSIX) Enable RTS/CTS (hardware) flow control. to these common problems, but in order to save his sanity (he kept. The device will transmit if CTS is active and will drop RTS if it cannot receive any more. We can set the CRTSCTS by "stty -F /dev/ttyS0 crtscts" 3、I have some question. kernel. CRTSCTS (not in POSIX) Enable RTS/CTS (hardware) flow control. 03 at windows 10 64 bit, using cygwin32 bit and i am trying to include #include <termios. org, neil. cu command modify "crtscts" option and the only way to push it forward is to run "stty -F /dev/ttyS0 -crtscts". print all current settings in human-readable form. > CRTSCTS constant will be defined. org Cc: <stable@vger. Share. open and use the specified DEVICE instead of stdin. Suspends output until the CTS (Clear to Send) line is raised. I understand that the normal way to use this device is to download the driver for your favorite OS, install it, and then it's plug-and-play. sudo stty -F /dev/ttyS0 -a. This enables RTS/CTS hardware flow control in the Linux device driver. > > > > > > Signed-off-by: Konstantin Shkolnyy <konstantin. Negated "Request To Send" (-12 volts) means "request NOT to send to me" (stop sending). Society for Cardiothoracic Surgery in Great Britain & Ireland 38-43 Lincoln's Inn Fields, London, WC2A 3PE. 2. A "modem disconnect" apparently involves toggling the RTS line, because once that flag is disabled, the behavior goes away regardless of the CRTSCTS flag setting. You can find the rest described in the. h file for Flow control:. Breaks can be generated by the TCSBRK, TIOCSBRK and TIOCCBRK ioctl() calls. stty sane. ICANON Enable canonical mode (described below). 0. g. 45 Element Plus Version: 2. The termios functions describe a general terminal interface that is provided to control asynchronous communications ports. If you're not using RTS/CTS, there's also the ixon setting that enables XON/XOFF flow control, but you may not want that. The two changes above ensure that hardware. To match a <Nul> with a search pattern you can just enter CTRL-@ or "CTRL-V 000". But qemu can not get the hardware flow control of the guest set。You may wish to try some invocatoin of stty (your example looks a bit like a "stty cbreak" or "raw" mode). Then, CTS/RTS was not effective, and I have been worried for a long time. 2. 3. Input modes. 8 for more details. Then without exiting the communications program (such as minicom) see if the device driver knows about. a", "xlnx,xuartps";I am using an RS485 to USB adapter in order to communicate with hardware, whose parameters can be changed by sending data strings in hex. org, neil. 0. Here is the stty command I executed. 1 and the other end of the link will be 10. If the code in his first post had a delay of a few seconds after the port setup it would work OK. 终端有三种工作模式：规范模式（canonical mode）、非规范模式（non-canonical mode）和原始模式（raw mode）。. 6. 16. 209 compatible = "xlnx,ps7-uart-1. In ~/. Those boards are based on chips FT232RL CH340G CP2102 and others. printf(" ttyACM0 Opened Successfully ");I. While it's not part of POSIX, it's present on Linux, Mac OS X, BSD. PARENB is defined in header termios. 0. Detailed Description. 0-48-generic Hardware Flow Control (CRTSCTS) If the CRTSCTS field is set, hardware RTS/CTS flow control is enabled. We can acquire some information by "stty -F /dev/ttyS0 -a ". hupcl -hupcl, Stop asserting modem control (do not stop) asserting modem control on last close. I've tried to export TERM with: linux, xterm, xterm-color, xterm-256color, ansi, screen-256color,. 3. 1 -chap modem #noauth -pap persist #maxfail 0 #holdoff 10 The passive option limits the number of (re)connection attempts. Linux > echo élève > française Linux > od -c française 0000000 303 251 l 303 250 v e 0000010 Linux > ls | od -c 0000000 f r a n 303 247 a i s e 0000013 Linux > ls françaisethe bind-key command in this solution also causes ctrl-h to correctly be sent when typing c-h, and the keyboard backspace to correctly be <del>. This section describes the terminal flags and fields that control parameters usually associated with asynchronous serial data transmission. It uses the UDP port 1701 to communicate. Using PPP across a null modem (direct serial) connection. When any of the characters INTR, QUIT, SUSP, or DSUSP are received, generate the corresponding signal. crtscts (-crtscts) Enable (disable) RTS/CTS flow control. 255. We can acquire some information by "stty -F /dev/ttyS0 -a ". May be negated. 串口通过termios进行配置。. el7 How reproducible: Connect to the server using L2TP. I typically use screen (1) to open a serial port with the command: sudo screen /dev/ttyUSB2 115200. 1 Answer. 83. parmrk (-parmrk) Mark (do not mark) parity errors. inputrc and add this line: "C-H":"C-W" Now, open a new terminal and it should work. 3. We can set the CRTSCTS by "stty -F /dev/ttyS0 crtscts" 3、I have some question 1) Does the qemu init all pci-serial port crtscts or raw? For example, I make the qemu configure with 4 pci-serial port. Here is what I see from [dmesg --follow] at 4Mbaud. > Possible solution would be to not allow to setup crtscts on such port. Already have an account? Sign in to comment. Although I expected it to read the 4 characters I just wrote it seems that read reads 0 bytes. All examples have been derived from miniterm. Sign up for free to join this conversation on GitHub . Examples. -g, --save. I set: sudo chmod o+rw /dev/ttyUSB0 stty -F /dev/ttyUSB0 1. com, gregkh@linuxfoundation. 320175E+03,+0. Reset all terminal settings to "sane" values; this has the effect of "fixing" the terminal when another program alters the terminal settings to an unusable condition. stty -F /dev/ttyPS1 crtscts. There are multiple ways of doing things because there were never any protocols built into the standards. The CRTSCTS is (not in POSIX) Enable RTS/CTS (hardware) flow control. I had been setting crtscts in the terminfo, but we did not have the pins connected. Re: How to enable CTS RTS for Raspberry Pi 3 b+ UART. I've tried setting parenb (and a number of other things) using the following command: sudo screen /dev/ttyUSB2 115200,cs8,parenb,-parodd,-cstopb. You can use strace to diagnose and chat -v should show all characters received. 29%” and some “RxData DMA copy to tty layer failed”. Asking for help, clarification, or responding to other answers. Let's assume that I run a program which reads/writes to a serial port (/dev/ttyS0). CRTS. termios是在POSIX规范中定义的标准接口，表示终端设备，包括虚拟终端、串口等。. Hi all, I am trying to using hardware flow control of the UART, and I would like that Linux would handle automatically the RTS and CTS signals, but I think I am a little bit confused about the topic. 3 Invoking Screen. It also contains the no longer supported option "lock". [ 41. Hey there ;-) Actually I've already got this set, however as far as I can tell this (crtscts) only turns on the hardware flow control, I cant use it to stop and start data. The low level serial hardware driver is responsible for supplying port information (defined by uart_port) and a set of control methods (defined by uart_ops) to the core serial driver. 現在のすべての設定を人間に読める形式で出力する. The machine has a small input buffer and uses hardware flow control to signal when it has completed a command and can receive a new one. crtscts. brkint (-brkint) Signal (do not signal) INTR on break. paste : Ctrl + v. To enforce a. It's possible to setup a serial port communication using hardware flow control with the RTS/CTS pins (CRTSCTS flag for tcsetattr), but there is no way to use the DTR/DSR pins for flow control in a reliable and efficient way. 説明. Sign up for free to join this conversation on GitHub . crtscts Specifies that pppd should set the serial port to use hardware flow control using the RTS and CTS sig‐ disconnect script Execute the command specified by script, by passing it to a shell, after pppd has terminated the link. stty -F /dev/ttyUSBx -crtscts. As you say, C-x @ is used for possible-hostname-completions. It's possible to setup a serial port communication using hardware flow control with the RTS/CTS pins (CRTSCTS flag for tcsetattr), but there is no way to use the DTR/DSR pins for flow control in a reliable and efficient way. This command will display all the settings for the specified UART device. To be able to output the value I use the following code using termios libraries:I want to read data from UART, i followed this tutorial, the write function works as expected, however i'am getting problem with the read function : This is the uart_init function: void uart_init(). Uses the state of CTS signal to do outbound flow control and RTS signal to do inbound flow control. Is it possible to check those parameters from terminal ? I have tried setserial -g /dev/ttyS0. Serial port initialization. 2 netmask 255. @@ -828,7 +833,7 @@ static void sc16is7xx_set_mctrl (struct uart_port *port, unsigned int mctrl) + to disable CRTSCTS from now on. 16. Specifies that pppd should set the serial port to use hardware flow control using the RTS and CTS signals in the RS-232 interface. NOTICE: ATF running on XCZU9EG/silicon v4/RTL5. For example (the usual): to highlight a word/sentence: Shift + arrow key. tty. igrr closed this as completed on Feb 10, 2015. or this: sudo screen /dev/ttyS0 115200,cs8,-parenb,-cstopb,inlcr,onlret,echo. > > Signed-off-by: Pavel Krasavin <pkrasavin@imaqliq. This can be verified by the command. 너무 복잡해 설명하기가 힘드나 위에서 6번째 줄 끝에 crtscts라고 나와있다. com> Hi, This is the friendly patch-bot of Greg Kroah-Hartman. The stty command has a crtscts flag that enables hardware handshaking on a device; you'll need to use this. (Default is 5 seconds. Architecture: AVR Component: Toolchain Type: Bug labels. tty. armstrong@linaro. stty -echo. If neither the crtscts, the nocrtscts, the cdtrcts nor the nocdtrcts option is given, the hardware flow control setting for the serial port is left unchanged. # stty -a speed 38400 baud; rows 59; columns 208; line = 0; intr = ^C;QNX Momentics IDE User's Guide. Introduction 华为me909s是基于海思芯片方案的物联网无线通信模块，ME909s系列4G模块集成华为海思芯片平台，继承华为领先的LTE技术，集成DDR降低成本，采用车规级质量管控。同时作为全球首款Cat4 LTE工业模块，同步开放FOTA易升级、降低维护成本。 ME909s系列是车载、跟踪、工业路由器、安防监控mossheim added this to the 3. I have successfully emulated a direct serial connect with a windows client (Windows 2000) with a CentOS 8 dial-in server (mgetty+pppd) between two virtual machines (Windows 2000 is client and CentOS 8 is server), using libvirt in Slackware Host. But /dev/ttyS* ports are full-duplex, with CRTSCTS or without, > so they don't use such handshaking. crtscts Specifies that pppd should set the serial port to use hardware flow control using the RTS and CTS signals in the RS-232 interface. cstopb -cstopb: Use two (one stop bits per character. a:對ttymxc0. Hello! I am trying to read data from the UART port telem2 i. Re: enable/disable RS232 flow control. There are at least two compilation errors below. xl2tpd: unrecognized option 'crtscts' The crtscts option seems to come from ppp-options. RTS will be asserted except when the kernel input buffer is full. hMon, 14 Jan 2019 14:21:49 +0800 (GMT+08:00) Hi, I followed How to use an ASYN record to communicate with a message-based instrument to build my example. I'm trying to use RTS/CTS flow control with CP2102N / CP2104 devices on Mac OS. crtscts mru 576 mtu 576 passive 10. These differ in name and location between PPP 2. Then, we just set up our script. c_cflag &= ~CRTSCTS; tty. */The Belkin F5U109 seems to be a device of fairly old design, so perhaps the F5U409 with the same usb vendor:device id is similar. -F, --file = DEVICE. dmbaturin closed this task as Resolved. 16. h file also supports ioctl modem-control operations. Serial-HOWTO 의 7 장을 참조할 것. This module provides an interface to the POSIX calls for tty I/O control. We can set the CRTSCTS by "stty -F /dev/ttyS0 crtscts" 3、I have some question. all: uart_test. CRTSCTS (not in POSIX) Enable RTS/CTS (hardware) flow control. -a, --all. 2 $ uname -r $ 3. petalinux is using 2019. But I would like to be able to use the keyboard instead of mouse to do those things. stty -F /dev/ttymxc0 raw ispeed 9600 ospeed 9600 cs8 -ignpar -cstopb -echo . Select option 5, Interfacing options, then option P6, Serial, and. 12:195. See sect. Note that RTS+CTS almost spells: crtscts and the initial "c" means "control". org> Subject: FAILED: patch "[PATCH] tty: serial: meson: fix hard LOCKUP on crtscts mode" failed to apply to 5. After that, CTS/RTS became effective. serial stty CommandsFor instance, STTY=crtscts enables outbound hardware flow control. 168. o cc -o uart_test uart_test. We can acquire some information by "stty -F /dev/ttyS0 -a ". 0. 0. But the most serious issue is that you only manipulate the RS-485 control lines one time, whereas I would expect these control lines to be toggled between read and write modes for proper half-duplex operation. Either: A. 100. $ stty -F /dev/ttymxc2 crtscts and disable flow control with $ stty -F /dev/ttymxc2 -crtscts To view the current settings for UART3, use $ stty -a -F /dev/ttymxc2 Just replace /dev/ttymxc2 with the name of the UART device. microcom -s 115200 /dev/ttyPS1. Edit 1: Forgot to include lsusb and ls /dev/ttyUSB*: Bus 002 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB. 数据位指的是每字节中实际数据所占的比特数。. once fixed (if it works) you'll have an easier time to investigate. TCSANOW, a) // Flush flushes both data received but not read, and data written but not transmitted. 最近のアップデートでcrtsctsとlockというオプションがなくなったらしく、これをコメントアウトしないとxl2tpが起動に失敗してしまう。 options. I'm using the eval kits CP2102N-MINIEK and CP2104-MINIEK, respectively. 2 Apr 22 2021 - 23:19:25. 0. Opening of Serial Port. conf file contains configuration information for xl2tpd, the implementation of l2tp protocol. I can set up RTS line on mangOH green but I cannot do it on FX30. org Cc: <stable@vger. -a, --all print all current settings in human-readable form -g, --save print all current settings in a stty-readable form -F, --file = DEVICE open and use the specified DEVICE instead of stdin --help display this help and exit. RTS (strictly, nRTS) is driven low when the UART is ready to receive data. Sun Feb 16, 2020 6:26 pm. open and use the specified DEVICE instead of stdin. 1. You can use strace to diagnose and chat -v should show all characters received. If the tty (4) TIOCFLAG_CRTSCTS flag has been set on the port then the CRTSCTS flag will automatically be set on every open. UNIX에서 시리얼 장치를 다루는 것은 시리얼 터미널의 전통적 방법에 크게 의존하고 있다. Teams. An easy way to set the various flags in a termios struct for this mode is to use cfmakeraw (3). I've ran into this problem before, there is a combo key that you can press to send the correct char code to do your deleting. Yesterday, after enabling the FCM of 0xFF000024 directly with the devmem command, stty -F /dev/ttyPS1 crtscts. print all current settings in a stty-readable form. It works when I'm not root. c_cflag &= ~CRTSCTS; tty. -echo. Check our new training course. If not, then there maybe a flow control issue. The output will look like that shown in Example 4-2. Some serial ports (such as Macintosh serial. So there is technically still not enough information about this issue to answer this question with certainty, but I am going to share how I would debug this isssue, only knowing what is in the question, explaining each step along the way. CRTSCTS. The UART may not be configured to use them. 2、 Uart 設定為 RTSCTS 下. You would need a baud rate of less than 32 baud to achieve a quarter-second break. c_cflag |= PARENB | PARODD; The full source code is listed as follows: Copy. This is how you should do most stuff in Qt, In order to be able to act upon multiple events that may arrive at any time. This allows the UART to be used for ter- minals, modems and serial line IP applications. init 1200 cs7 -parodd parenb -cstopb -icanon -iexten -ixon -ixoff -crtscts cread clocal echo -echoe echok -echoctl. This enables RTS/CTS hardware flow control in the Linux device driver. com> Subject: [PATCH 6. The current sum is: 5. Addendum. I was hoping to read from this device using a simple bash script, but can't find any way to set the handshaking lines, using stty or otherwise, to allow for the above configuration. . [requires _BSD_SOURCE or _SVID_SOURCE] c_lflag flag constants: ISIG. This tutorial shows you how to use PARENB. h and in asm/termbits. stty echo. 数据位指的是每字节中实际数据所占的比特数。. and it actually seem to work. How are these two escape sequences usually handled in C?1. As a data nerd I wanted to know how much power I am consuming or feeding-in with my solar inverter. – user2430607. ) Specify an initial speed instead of the hardware default. And while debugging i can se that the software is stopping here . If that doesn't work try shift + backspace / del. A half duplex modem cannot be used on a full-duplex-only port. This patch was tested with success with a serial printer configured with a small buffer. I have a serial device that has no flow control, but is powered from the RS232 port by holding the RTS high and DTR low. # stty - change and print terminal line settings # # -F /dev/ttyUSB0 Change the settings of /dev/ttyUSB0 # cs7 Use 7 character bits # parenb Enable the a parity bit # -parodd Don't use ODD, but use EVEN parity # -cstopb Don't use 2 stopbits, but just the regular 1 # crtscts Enable RTS/CTS handshaking (hardware flow control) stty -F /dev/ttyUSB0. print all current settings in human-readable form. Your code can be rewritten like this: #include <QtSerialPort> int main (int argc, char* argv. 1. h and in asm/termbits. uart 通信のテストをする c のプログラムです。. Configuration -> Windows -> Translation -> Remote character set : UTF-8. My termios setup is modifying the first character read from the serial port using read (). Description: public const int CRTSCTS*FAILED: patch "[PATCH] tty: serial: meson: fix hard LOCKUP on crtscts mode" failed to apply to 4. The cool thing is, if I send "stty -F /dev/ttyACM0 -cstopb -crtscts cs8 9600 ; echo "ver" >>/dev/ttyACM0" when I open a "screen /dev/ttyACM0" the version value is sitting there, so I know Im talking to it, but it cant. stty -f /dev/ttyu0. You cannot generate a break condition by manipulating the baud rate. Re: enable/disable RS232 flow control. # stty -a speed 38400 baud; rows 59; columns 208; line = 0; intr = ^C; QNX Momentics IDE User's Guide. stty -a. linux. -a, --all. Bug Type: TypeScript Environment Vue Version: 3. You use whatever ad-hoc "standard" your equipment implements. Feb 11 2021, 2:25 PM. Note that CRTSCTS support is hardware and driver dependent. 04. CRTSCTS : 하드웨어 흐름 제어. h> SoftwareSerial mySerial(0, 1); //. crtscts. When the PC is ready for more bytes. Configured minicom to use hardware flow control (Ctl A-O to open minicom serial port setup menu, and F to enable hardware flow control). I have confirmed that when sending a character from Linux on the Zynq-7035, out the /dev. Serial ("/dev/ttyACM0") ser.