I am using a custom built cape for my application, so I have not tested it. Though according to the schematics it looks like the chip does not support those rates.
According to the schematic at: http://beagleboardtoys.info/index.php?title=BeagleBone_RS485 It looks like the RS485 cape uses a TI transceiver part no: SN75HVD12D http://www.ti.com/lit/ds/symlink/sn75hvd12.pdf <https://lh6.googleusercontent.com/-iazVOLORISQ/Up4HgMpjUQI/AAAAAAAAA54/FZqOvYcHf28/s1600/12-3-2013+10-31-36+AM.png> Should be able to go up to 1Mbps, but not much higher. Checking the ARM Datasheet (AM335x ARM Cortex -A8 MPU Technical Reference Manual): 19.1.1 UART Mode Features The general features of the UART/IrDA module when operating in UART mode are: - 16C750 compatibility - Baud rate from 300 bps up to 3.6864 Mbps - Auto-baud between 1200 bps and 115.2 Kbps Since on the ARM side, you have slightly higher max data rates, so if you had a faster chip you could approach the rate you need given the right design. If you need faster than what is natively on the ARM, you could look into a custom solution with the PRU, but I don't have any experience with that. Zach On Tuesday, December 3, 2013 6:17:45 AM UTC-6, [email protected] wrote: > > Hi Mika, > > I need to go two orders of magnitude higher (3.8 Meg, for a short distance > of six feet, half duplex). Is there a chance with BBB? > > Thanks, > Haik > > On Tuesday, December 3, 2013 3:40:39 AM UTC-5, Mickae1 wrote: >> >> Hi, >> >> Well, I'm working with the BaudRate 38400 and I don't have any problem. I >> didn't try further. >> >> micka, >> >> >> On Tue, Dec 3, 2013 at 3:13 AM, <[email protected]> wrote: >> >>> Hi all, >>> >>> Interesting Work! What is the max baud rate you can get from this rs485 >>> cape on BBB? >>> >>> Haik >>> >>> >>> On Friday, June 21, 2013 5:54:29 AM UTC-4, Mickae1 wrote: >>>> >>>> Hi all, >>>> >>>> Yes I did it ^^, I successfully made my BBB ( Kernel 3.8.x ) work with >>>> the *RS485 CAP ( I was able to talk with my PC with a USB<>RS485 >>>> adaptater ) * >>>> >>>> To do it, I modified the Kernel (omap serial driver) and I tested it on >>>> a Ubuntu Distribution ( Why ? Because I don't know how to modify the >>>> source >>>> code of the kernel with an angstrom distribution. And Robert Nelson >>>> explain >>>> very well how to do it with a Ubuntu distribution). >>>> >>>> It's true, that the eMMC use the GPIO1_0 & GPIO1_4 of the BBB and the >>>> RS485 cap need them, but it's also *easy *to disable the virtual cap >>>> eMMC! Just a simple echo -4 > $SLOTS do the trick. >>>> And I also had to create my own rs485 virtual cap to enable the GPIO1_0 >>>> & GPIO1_4 & UART1_TX & UART1_RX >>>> >>>> But now, for my project I need to cross compile, and it looks like that >>>> there is no toolchain on the ubuntu distribution (working with the Robert >>>> Nelson Ubuntu distribution). >>>> >>>> So I'm going back to the Angstrom distribution, but my problem is that >>>> I don't know where to put my patch ? Will it work ? I don't know how to >>>> create a patch, I just did this command : " sudo git diff > >>>> ../rs485.patch" >>>> ( Robert Nelson => on your KERNEL folder ) >>>> >>>> I read here => http://downloads.angstrom-distribution.org/demo/ >>>> beaglebone/ >>>> >>>> That i can create my own image, with this : >>>> >>>> git clone git://github.com/Angstrom-distribution/setup-scripts.git >>>> >>>> cd setup-scripts >>>> >>>> ./oebb.sh config beaglebone >>>> >>>> MACHINE=beaglebone ./oebb.sh bitbake systemd-image >>>> >>>> >>>> My question is where I can put my patch ? Or where I can modify the >>>> Kernel ? >>>> >>>> >>>> Thx you every one, It's because of your help, That I was able to make >>>> this Work ! >>>> >>>> >>>> I will soon explain my work on this project in my blog. >>>> >>>> >>>> >>>> Michael Musset, >>>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >> >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
