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Topic: Registers access - where to start? (Read 345 times) previous topic - next topic

Vaclav

I have a "side job / spare time " project to build a code to use Noritake display in "inverted serial mode".
I prefer not to use / share standard "Serial" port code, inverting and sharing ( with Serial and LCD) the serial stream caused much headache on Uno.

I have never done any "low level" AKA using registers coding and could use some guidance.


Reading hundreds of pages of ATmel documentation on ARM processor(s) is little overwhelming.
And yes, last time I checked with  Noritake they do not have "sample code" to use on ARM, just AVR which does help.

 My next step is to analyze Due "Serial" code to get some idea.
Cheers Vaclav
 

MorganS

What is "inverted serial mode"? A quick Google search only returns results for inverted text. Do you mean inverted mark/space polarity? Like RS-232 but at TTL voltage levels?

The UART and USART hardware in the Due is extremely capable. I'm sure that just setting the right options will allow standard code to send&receive inverted serial. The INVDATA bit in the mode register probably does what you want.

The standard Arduino Due serial code is probably not a good example to follow. There are some significant problems, although the open-source community is working on it.

Vaclav

What is "inverted serial mode"? A quick Google search only returns results for inverted text. Do you mean inverted mark/space polarity? Like RS-232 but at TTL voltage levels?

The UART and USART hardware in the Due is extremely capable. I'm sure that just setting the right options will allow standard code to send&receive inverted serial. The INVDATA bit in the mode register probably does what you want.

The standard Arduino Due serial code is probably not a good example to follow. There are some significant problems, although the open-source community is working on it.
I do not have easy access to Noritake description of "inverted serial" , but essentially whatever standard polarity is ( mark / space ) they invert it. It is no big deal, but when I shared the serial port on Uno it got too clumsy to keep track when to use standard and when to switch to inverted and back. On top of that the baud rate ( on Noritake hardware)  is fixed and again switching the register timing was a pain.
One of the reasons I switched to Due so I can have a dedicated serial port for Noritake - no more switching mess.
My goal is to use Noritake display as "enhanced" ( 6x30) debugging tool replacing my current LCD.
I'll take a look on the INVDATA , thanks.
 

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