RS-485 on AM335x

Jan Lübbe

Other Parts Discussed in Thread: PROFIBUS

Hi all,

according to http://www.ti.com.cn/general/cn/docs/lit/getliterature.tsp?literatureNumber=spry155a&fileType=pdf
ProfiBus/RS-485 is available for the AM335x. The transceiver seems to be connected to the PRUSS.

Which pins should be used for connecting the transceiver to be able to use this?

Regards,
Jan

over 13 years ago

0 Frank Walzer over 13 years ago

TI__Mastermind 44306 points

Jan,

you need ICE (http://www.ti.com/tool/tmdxice3359) and IA-SDK (http://www.ti.com/tool/sysbiossdk-ind-sitara) references.

The first contains the schematics and the second has the matching software including a Profibus demo.

Regards.

0 Jan Lübbe over 13 years ago in reply to Frank Walzer

Prodigy 90 points

Thanks for your quick reply,

I've checked the ICE schematics before, but am not sure which function is muxed to the relevant pins (UART1_TXD, UART_RXD, GPIO3_19).
For the HW design I'd need to know if GPIO3_19 is simply used as a GPIO from the PRU or if the McASP is involved.
If other pins could be used for RS-485, it would be good to know our options.

Regards,
Jan

0 Jan Lübbe over 13 years ago in reply to Jan Lübbe

Prodigy 90 points

Do you have any documentation regarding the PinMux alternatives when using RS-485 on the PRU?

Regards,
Jan

0 PratheeshGangadhar over 13 years ago in reply to Jan Lübbe

TI__Mastermind 47911 points

Technically you can use any GPIO muxed with PR1_PRU0_R30x, where x=0 to15. But stock PRU firmware for PROFIBUS support only PR1_PRU0_R30[5] muxed with GPIO_3_19. If there is a compelling reason we can consider making this programmable to use any one of these 16-pins.

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RS-485 on AM335x