MiniUART

On the rPi there are two UARTS:
- PL11
- MiniUART
I’m in the process of writing code for the MiniUART of the rPi. This discussion was partly in another forum topic:https://www.riscosopen.org/forum/forums/5/topics/9229
The code is written is written in C instead of assembler and uses the ROOL compiler

Nice work, Timo! It would be great to see the code.

Hi Mikko,

Please find the code here. Please note it is work in heavy development. And not an example of software engineering and perfect code

Perfect code only lives in textbooks, Timo!

Thanks for sharing.

TBH I’ve just been programming in BASIC in RISC OS but I do know a bit of C and have the NutPi DDE so this is a good opportunity for me to explore it…

You are most welcome. If you find any mistakes please let me know.

So and again a little progress starting on the DeviceFS side of things:

More progress and quite important the receive interrupt prototype now works. That was quite looking how that worked.
Also nice that I was helped by one of the members of the Big Ben Club during the club evening in Delft. Four eyes see more than two. For example that I used != instead of |= ;-)

For example that I used != instead of |= ;-)

http://www.riscos.info/packages/DevelopmentDetails.html#Cppcheck

cppcheck is a bit of a pain to use (seems to like not finding stuff (filename issues?) so I check my files one by one) but it is useful for giving the code a check to find various problems that compilers aren’t designed to find (compilers check the source is correct, cppcheck checks that what the source does is correct).

That is indeed a handy tool which will speed things up.

Hi thanks to David I now have dedicated web space for RISCOS. Please find the source code until so far. Please note as long it is not indicated as ‘release’ it is code under development:

MiniUART

An update on the code. You will find an improved prototype of the interrupt code. And a number of global variables have been removed and replaced by better alternatives. The code is still under development and can be found under.
MiniUART
( Code update 28 September 2018 )

On 4 oktober 2018 I worked on the receive interrupt code and the device driver code:
MiniUART
( Code update 4 oktober 2018 )

Update on the source available on the well known address ;-). In this case I worked on the validation string. So we can set the baudrate while opening the com port

Hi ,

I bumped into a problem the receive interrupt routine only receives 9 charakters and then nope data anymore. I have no idea what is happening there….

At a guess the buffer size of the MiniUART is 8 and its overflowed?

It would say that is the case and after a good(?) night sleep I also realized something else and that is something on the sending side.

An update on the code ;-)
- More code duplication removed
- Less calls to OS_Memory

It can be found all on :
Code

There was some time no update on this project. But I’m happy to tell that I can now send data successfully and no data is lost anymore. To solve this a FIFO is used to send the data. One can find the source on:
RISOC
Look under MiniUART. Also the module is here available for download. Please note a SWI range is used on which no application is done. So you could have clash.

I was a little bit too happy so it seems. With bigger chunks of data it didn’t went so well. It seems to be solved. Still open items in the MiniUART module:
- Testing of the software
- Implementation of modem control
- Use of the MiniUART HAL in the ISR
- Implementaton of Ioctl
Please find the update source code here :
1 June 2019 Code