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Author Topic: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup  (Read 839 times)

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Offline yarshevichTopic starter

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Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« on: February 19, 2013, 04:23:22 PM »
What are USART settings for Axon Mote (channel 0) to operate properly with on-board FT232R USB bridge?
  - character size (looks like 8 bit is used)
  - parity bit mode (even or odd, if supported at all),
  - baud rate,
  - etc.
Does FT232R operates in synchronous or asynchronous mode with Axon Mote?
Does FT232R wired to support duplex transmission with Axon Mote?

We are trying to program UART "manually", e.g. we do not use WebBotLib in our project. So we need a setup configuration for on-boar USART port 0, that is connected to the USB bridge.

If no information available, will have to dig into WebBotLib generated project to get default working settings. However knowing all the supported options would be very helpful.

PS: Could someone please add this information to the Axon Mote datasheet page?
PPS: Datasheet link to Atmel website is also outdated. New one is http://www.atmel.com/devices/atmega128rfa1.aspx?tab=documents

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Re: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« Reply #1 on: February 21, 2013, 12:04:42 PM »
The answers to all your questions are in the reference links:
http://www.societyofrobots.com/axon_mote/axon_mote_datasheet.shtml#references

Quote
What are USART settings for Axon Mote (channel 0) to operate properly with on-board FT232R USB bridge?
  - character size (looks like 8 bit is used)
  - parity bit mode (even or odd, if supported at all),
  - baud rate,
  - etc.

If you are manually programming it, it can be whatever you program it to be. :P

If using WebbotLib: character size is 8, no parity, 1 stop bit, and hardware flow control.

Quote
Does FT232R operates in synchronous or asynchronous mode with Axon Mote?
Does FT232R wired to support duplex transmission with Axon Mote?

asynchronous; it's based on the USB standard


Quote
PPS: Datasheet link to Atmel website is also outdated. New one is http://www.atmel.com/devices/atmega128rfa1.aspx?tab=documents

thanks, I'll update it

Offline yarshevichTopic starter

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Re: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« Reply #2 on: February 21, 2013, 06:30:50 PM »
Thank you for the update!

Quote
If you are manually programming it, it can be whatever you program it to be. :P

Form the documentation for FT232R it does not recognize baud rate and other settings automatically (how could it do?), instead those settings for UART are programmed in chip's EPROM. but I double check it.

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Re: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« Reply #3 on: February 21, 2013, 09:19:37 PM »
You don't need to worry about the FT232R. Whatever baud rate you send data to it from your computer USB, it will spit out TTL data at that same baud rate to the Axon Mote.

And vice versa.

Offline Webbot

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Re: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« Reply #4 on: February 21, 2013, 09:45:14 PM »
Quote
If using WebbotLib: character size is 8, no parity, 1 stop bit, and hardware flow control.

There is no flow control
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

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Re: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« Reply #5 on: February 21, 2013, 10:26:42 PM »
oops, typo! thanks for catching that  ::)


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If using WebbotLib: character size is 8, no parity, 1 stop bit, and hardware flow control.

There is no flow control

Offline yarshevichTopic starter

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Re: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« Reply #6 on: February 23, 2013, 01:32:58 AM »
Well, baud rate 9600 didn't work with FT232R  :(.

At the same time USART 1 works fine with this rate (loop-back test, etc).

After reverse engineering some sample code from tutorials I found rate value 230400. And at least with this rate some data is coming through the FT232R to virtual COM on Win7 PC. :)

Offline yarshevichTopic starter

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Re: Axon Mote to USB bridge (FT232R) - ATmega USART channel 0 setup
« Reply #7 on: February 24, 2013, 01:09:32 PM »
Quick update.. 9600 is fine too.

Was an overflow error in baud rate register value calculation (8-bit MCU has it's limits too ;))

 


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