tag:blogger.com,1999:blog-6238454757421809452.post5953642934014245338..comments2024-01-29T06:22:58.174-05:00Comments on The Raspberry Pi <br>Hobbyist: Raspberry Pi Serial PortTed B Halehttp://www.blogger.com/profile/16887056993667506084noreply@blogger.comBlogger20125tag:blogger.com,1999:blog-6238454757421809452.post-20599237592502041042017-05-11T05:50:10.604-04:002017-05-11T05:50:10.604-04:00I have previous experience with PACKT publishing. ...I have previous experience with PACKT publishing. I am most definitely NOT INTERESTED in dealing with you again.Ted B Halehttps://www.blogger.com/profile/16887056993667506084noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-28805396878465556432017-05-11T03:41:36.196-04:002017-05-11T03:41:36.196-04:00Would like to contact you for creating a course on...Would like to contact you for creating a course on Raspberry Pi 3 with Packt Publishing. Would you be interested?Anonymoushttps://www.blogger.com/profile/12731907765266464967noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-50911770885579906282016-06-20T10:08:02.952-04:002016-06-20T10:08:02.952-04:00Yes, this is still the same for the Pi 3.
One hard...Yes, this is still the same for the Pi 3.<br />One hardware change from the design above that I recommend is to use a MAX3232 instead of a MAX232. The MAX3232 is designed for 3.3V systems so you won't need to convert the voltage for the Pi.Ted B Halehttps://www.blogger.com/profile/16887056993667506084noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-29459857660817085242016-06-19T16:59:23.383-04:002016-06-19T16:59:23.383-04:00Thanks for posting this, but before I head down th...Thanks for posting this, but before I head down this path, I'm wondering if this is still a correct procedure for use with the Raspberry Pi 3?<br />Anonymoushttps://www.blogger.com/profile/03366694273791832023noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-84594692669668450402015-03-25T12:15:17.205-04:002015-03-25T12:15:17.205-04:00The changes should survive a reboot. What OS are ...The changes should survive a reboot. What OS are you using? I did this on Raspbian Linux. It is possible that there are changes related to device tree overlays in the latest version that affect the serial port. I will look into that.Ted B Halehttps://www.blogger.com/profile/16887056993667506084noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-39286992927818067972015-03-25T01:53:56.161-04:002015-03-25T01:53:56.161-04:00Hello Ted, Useful Post! Thanks for sharing :)
I h...Hello Ted, Useful Post! Thanks for sharing :)<br /><br />I have a question:<br /><br />How to permanently disable the serial port?<br />It seems that the changes suggested by you does not survive a reboot! <br />So any insights upon how can I do that?Anonymoushttps://www.blogger.com/profile/10855435137532870376noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-57757892244008868072014-04-29T11:37:28.638-04:002014-04-29T11:37:28.638-04:00This comment has been removed by a blog administrator.Anonymoushttps://www.blogger.com/profile/04980535685968813949noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-64505307320716142332014-04-29T11:33:08.237-04:002014-04-29T11:33:08.237-04:00This comment has been removed by the author.Anonymoushttps://www.blogger.com/profile/04980535685968813949noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-23211909560758933152014-01-18T05:08:30.382-05:002014-01-18T05:08:30.382-05:00Hi,
I'm trying to do this on a Pi with Xbian i...Hi,<br />I'm trying to do this on a Pi with Xbian installed. The project is for a PWM controlled fan for CPU cooling my aggressively over clocked media centre. My desire to use the UART port comes from the fact that I have a nice three pin plug that connects to the ground, 5V and the UART Tx pin (as they are all in a row). I'd thus like to use that Tx as the PWM pin.<br /><br />However the cmdline.txt file has no references to the serial controller, nor does the equivalent of the login prompt for Xbian, which appears to be /etc/init/tty1.conf and is referenced directly in the cmdline.txt file:<br /><br />sdhci-bcm2708.sync_after_dma=0 dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootflags=subvol=root/@,autodefrag,compress=lzo rootfstype=btrfs rootwait smsc95xx.turbo_mode=N elevator=cfq logo.nologo quiet noswap loglevel=0 mod_scsi.scan=sync partswap startevent=mountall splash nohdparm --startup-event mountall<br /><br />The tty1.conf file reads:<br />start on stopped rc RUNLEVEL=[2345] and (<br /> not-container or<br /> container CONTAINER=lxc or<br /> container CONTAINER=lxc-libvirt)<br /><br />stop on runlevel [!2345]<br /><br />respawn<br />exec /sbin/getty -8 38400 tty1<br /><br />So, my question is: is there a way to disable the UART ports or is that step not even necessary?Anonymoushttps://www.blogger.com/profile/15384867567172983617noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-51332440759520083802013-10-06T11:47:15.052-04:002013-10-06T11:47:15.052-04:00I find connecting two Raspberry Pi, that between 1...I find connecting two Raspberry Pi, that between 10 and 50 percent of echos go missing this way, am I doing something wrong? <br />or to put it another way, I would like to send a single 8 bit number from one RPi to the other,<br />is there a simple way to ensure it is received?chadhttps://www.blogger.com/profile/00640243835424818843noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-20733077096670544862013-09-08T07:33:21.535-04:002013-09-08T07:33:21.535-04:00I've just written a neat little Bash script to...I've just written a neat little Bash script to automate the task of disabling the RPi's serial console, enabling it to be used as a regular 3.3V serial port.<br />https://github.com/lurch/rpi-serial-consoleAndrewShttp://www.andrewscheller.co.uknoreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-44426208028687211652013-07-11T12:30:30.313-04:002013-07-11T12:30:30.313-04:00Hi,
we can not use Rs232 direct normal port,
exa...Hi,<br /><br />we can not use Rs232 direct normal port,<br /><br />example;<br /><br />we can use pi's usb ports convert to usb - rs232 and we can see our PC terminal send or receive any data so no problem all OK<br /><br />but when we use direct pi's rs232 port GPIO15 / 16 pins... connect to MAX3232 and change for 3.3V then connec to PC after we can Pi send but can not any data take...<br /><br />if we want take any data for Pi we do send data 20 times or 30 times after Pi can take and show to terminal page this data... but we must do 20 or 30 times send from PC to Pi....<br /><br />but if we use Pi's USB port to PC Rs232 port every thing is OK good work... but Pi'original Rx/Tx pins not normaly work...<br /><br />so Please help to us for about...<br /><br />dmgsarac@parsnav.com you can send to me any email... I will wait...<br /><br />thanks alot...Anonymoushttps://www.blogger.com/profile/06666236919961930153noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-33804714241922161482013-06-26T05:01:58.403-04:002013-06-26T05:01:58.403-04:00Dear Ted,
thanks for this manual - this works just...Dear Ted,<br />thanks for this manual - this works just beautifully, especially thanks for the schematics. I'm using a MAX2323CPE here.<br />Maybe it'd be nice pointing out that the voltage levels on the RPI Rx and Tx are +3.3V without having a RS232 device attached to the MAX232, while the Rx drops to 0 when a device is sending bits.<br />Best regards! Steffen<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-30778028118492992522013-03-07T08:17:46.931-05:002013-03-07T08:17:46.931-05:00"which will work for 3.0 to 5.5V"
It wil..."which will work for 3.0 to 5.5V"<br />It will work from either for power.<br />However, the data pins are 3.3V so you don't need level convertors.Ted B Halehttps://www.blogger.com/profile/16887056993667506084noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-41818966389568535062013-03-06T20:41:30.443-05:002013-03-06T20:41:30.443-05:00And the MAX3232 chip needs to be powered from the ...And the MAX3232 chip needs to be powered from the 3.3 Volt GPIO pin 1 NOT 5V. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-53540479797211415132013-01-13T21:09:46.262-05:002013-01-13T21:09:46.262-05:00That is the typical MAX232 chip and does need capa...That is the typical MAX232 chip and does need capacitors.<br />The chip has to take 5V and produce +15V and -15V. In reality, it will typically only produce around 9V.<br />The chip uses a circuit called a "charge pump" to achieve this.<br />Capacitors are needed to store the additional charge required for this circuit.<br /><br />MAX232 chips are intended for 5V circuits. Since the Raspberry Pi is a 3.3V device, a better choice would be the MAX3232 chip, which will work for 3.0 to 5.5V<br /><br />There are versions of the MAX232 that have built in capacitors. Also, some versions use external 1uF caps while others use 0.1uF caps.Check the data sheet for whatever chip you use to be sure you have it right. Using larger caps than required is OK.Ted B Halehttps://www.blogger.com/profile/16887056993667506084noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-71458701767096850932013-01-12T22:43:10.931-05:002013-01-12T22:43:10.931-05:00Thanks for posting this! It's just what I was ...Thanks for posting this! It's just what I was looking for.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-76019582891523652982013-01-10T23:38:12.558-05:002013-01-10T23:38:12.558-05:00Hy,
Could you explain more about the purpose of t...Hy,<br /><br />Could you explain more about the purpose of the capacitors?<br /><br />I would use this IC http://sk.fotoarchiefje.nl/Datasheets/max232.pdf<br /><br />Does that mean it has built in capacitors and i don't need to use extra ones?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-45412960993315633362012-12-07T10:03:33.043-05:002012-12-07T10:03:33.043-05:00Need to stop OS from using the serial port as desc...Need to stop OS from using the serial port as described in the post.<br />(Feel free to use nano in place of vi as the editor.)<br /><br />Then set baud rate with command like:<br />sudo setserial /dev/ttyAMA0 baud_base 9600<br /><br />The you could do something as simple as <br />cat /dev/ttyAMA0<br />and any data from the serial port would echo on the console.<br />Hopefully not binary data, and line feeds (or a lack of them) can be a problem to readablility.<br />Press Ctrl-C to stop<br /><br />If you want a full terminal emulator on the console, you could use minicom.<br />If you are on X you could use gtkterm.<br />Ted B Halehttps://www.blogger.com/profile/16887056993667506084noreply@blogger.comtag:blogger.com,1999:blog-6238454757421809452.post-18674132280076241052012-12-06T17:07:08.344-05:002012-12-06T17:07:08.344-05:00How can I listen for data on AMA0 in the console w...How can I listen for data on AMA0 in the console without any other scripts? Anonymoushttps://www.blogger.com/profile/17448039022702636059noreply@blogger.com