R-Pi GPIO Alternate functions

Can anyone point me in the right direction please. How do I select alternate GPIO pin functions on R-Pi using RISC OS? Thanks in advance.

alternate or alternative ?

Broadcom datasheet uses both words.

Is Broadcom American? The two words have distinct meanings in English; they seem to be synonymous in American.

To expand upon this: “alternate” is typically an action of switching between states, while “alternative” is another word for choice or option.

For example, if a road is closed you will have to take an alternate route, however if you want to avoid traffic you might want to take an alternative route. The difference?
In the first case the original route doesn’t exist (road closed) while in the second case it does, your just going a different way.

So, yes, in proper English the words have subtlety different meanings.

The best definitive guide seems to be the StrongHelp manual for GPIO. Expect to have to read it many times before you really understand what you have to do, though. Remember that the difficulty that the GPIO module is trying to solve, is that the numbers required to set particular functions are not constant across all platforms – that’s why it is as convoluted as it is.

Expect to have to do lots of experiments, lots of trial and error, before you get things to work as you wish. Don’t be discouraged!

You may still find that, even if you can set an alternative function, you may not have any way to control it further; I’m thinking of PWM as an example.

If you run the !GPIOConfig program (version 0.54) and menu over a pin it will list the functions available on that pin. They are in order (0 to 7) so you can use the number counting from the top down to your required option.
Obviously you can set the pin up with the program as well…
This works on all builds with the v1.0 GPIO module so all supported boards.
This BASIC program will also list the pins and their functions.

So, yes, in proper English the words have subtlety different meanings.

An alternative reading of “alternate functions” in English English could be functions 0,2,4,6 instead of 1,3,5,7.

your just going a different way.

So, yes, in proper English the words have subtlety different meanings.

Of course, the tendency to abbreviate and then miss out the punctuation confuses things. As many people could of pointed out. :)

So, after all that I still am not sure what information Kim was looking for.

All I know, is that the GPIO works very well and with the aid of some Energenie switches and the Pi-Mote controller, it all controls my heating very well.

All I need now, is for it to turn it all off and turn some air contitioning on!

your just going a different way.

Blame Google. It’s their fancy on-screen keyboard that can’t tell the difference between your and you’re. ;)

I do catch a few of these upon reading the message I posted, but not all, as is evident.

Blame Google. It’s their fancy on-screen keyboard that can’t tell the difference between your and you’re. ;)

Presumably with autocorrect auto-bollox turned on :)

All I need now, is for it to turn it all off and turn some air contitioning on!

Apparently it’s too warm for aircon – or least the dubious quality¹ installation in the UPS room for our secondary datacentre. The UPS didn’t like it and has gone into alarm.
On the upside, the only places in our building (different one) that are cooler than our office are the PBX room and the server room, and the server boys have migrated pretty much every system they can away from the possible fail zone.

¹ I say dubious, but I don’t think there is any doubt that the PFI providers installed the cheapest they could get away with.

Can I add that derailing a post to be a grammar pedant even before the question is answered only enhances the newcomers view that “the ROOL forums aren’t a friendly place”

The best definitive guide seems to be the StrongHelp manual for GPIO. Expect to have to read it many times before you really understand what you have to do, though. Remember that the difficulty that the GPIO module is trying to solve, is that the numbers required to set particular functions are not constant across all platforms – that’s why it is as convoluted as it is.

Also, the magic numbers for what mode equals what function are only found in the bit of the manual marked “Earlier versions of this manual…”, unless I’m missing them somewhere.

You may still find that, even if you can set an alternative function, you may not have any way to control it further; I’m thinking of PWM as an example.

You might also find that on a Pi4, trying to change the function of a pin may have no effect. I still can’t re-route PWM audio through to a GPIO pin on a Pi4/400, even though it works fine on other Pis and I can do it from Linux on a Pi4/400.

If you run the !GPIOConfig program (version 0.54)

Do you have a link the OP can use to download it from?

Do you have a link the OP can use to download it from?

It might be the link referenced in this thread: https://www.riscosopen.org/forum/forums/5/topics/17148

(Are we still allowed to post about RISC OS on here, without creating half a dozen other posts on politics, religion or grammar pedantry first?)

The politics stuff was in Aldershot, and the grammar pedantry actually made sense as the two words mean different things which could change the interpretation of the question…

Any more → Aldershot, m’kay?