I added a 232PTTL33 converter and now communication to the beaglebone works but communication from it to the computer doesn't work. The converter definetly is an improvement but not a complete solution has anyone else had good luck with it?
On Thursday, June 19, 2014 4:06:05 PM UTC-4, PLyttle wrote: > > When you say that the gps works on your windows box, I assume it has an > "com" interface, i.e. an RS-232 interface. > The BBB does not use this specification. it uses a "3.3v ttl". serial > connection. > > there are a few differences, > a: the voltage levels. RS232 specs allow voltages at least -25 to +25 volt > (common is -9 - +9 volts). BBB allows 0-3.3V > b: the logic. a '1' on RS-232 is *minus* 3-25 volt. a '1' on BBB is *plus* > 3.3 volt. > > Other things that can go wrong: > a: Not using a common ground. i.e only connecting rx and tx and assuming > the ground is good. > b: Using the wrong frame. 8 or 7 databits, 1, 1.5 or 2 stop bits > In all these cases a loopback will work, because the machine uses it's own > specs. > > c; there are crappy RS-232 - "ttl" converters on the market. > > please look up the RS-232 spec, If you don't know what you are doing you > can easily fry the BBB > > > success, LP > > On Thursday, June 19, 2014 3:49:31 PM UTC+2, Alvin M wrote: >> >> I'm working on a custom linux distro for our customer product. I've got a >> gps that works when I plug it into my windows machine but on linux at the >> same baud rate I'm getting gabled output. I've tested it on loopback and it >> seems to work fine for loopback other than some extra newlines. I had to >> manually set the pins to >> >> name: uart1_txd.uart1_txd (0x44e10984/0x984 = 0x0040), b NA, t NA >> mode: OMAP_MUX_MODE0 | AM33XX_SLEWCTRL_SLOW >> signals: uart1_txd | mmc2_sdwp | NA | i2c1_scl | NA | pr1_uart0_txd_mux1 >> | NA | gpio0_15 >> >> name: uart1_rxd.uart1_rxd (0x44e10980/0x980 = 0x0070), b NA, t NA >> mode: OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP | AM33XX_SLEWCTRL_SLOW >> signals: uart1_rxd | mmc1_sdwp | NA | i2c1_sda | NA | pr1_uart0_rxd_mux1 >> | NA | gpio0_14 >> >> >> stty settings >> speed 9600 baud; line = 0; >> intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; >> eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt >> = ^R; >> werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0; >> >> Any Ideas? >> > -- 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/d/optout.
