In Control

George asked:

Hello David,

Quick question if you don't mind regarding your convention in SKB for your use of the letter "t"

I've noticed t seems to refer to timer number in old scheme, but
tt )
tttt ) I'm wondering what the difference is.
tttttt )

Kell asked:

Hi David,
Is there anything in SPLat which will tell you if more than one bit has changed in a byte, like when you are reading grey code ? I have got 5 inputs and only one can change at any one time.

A gentleman in Heflin, Alabama wrote on August 13 2007:

I am disabled and in need of your help if you can, I have an old Niagra Theropy Electric Adjustable bed, My Control is messed up I need new switches or a new computer board rebuilt with the switches so the head of bed will go up and down, the legs will go up and down. I can send you the control to see if you guys can repair or rebuild me a new one to fit in the control case.

If anyone out there is in a position to spend a few hours helping this person, it would be great. Obviously it would be best if you are geographically close. If you are willing to help, please reply under "Post a Comment". I will forward you email address to the gentleman so he can contact you.

With apologies to Damon Runyon

I'm sitting at my desk late one afternoon, thinking I could get lucky and be out of here by 5 o'clock, when the phone rings. I pick up the phone and I say as follows: "Hello, SPLat support line".

On the 'phone this voice says: "Is 'dat 'de SPLat support line?".

Now, where I come from if someone answers the phone with "Mindy's Restaurant" I know I've gotten through to Mindy's. In fact, if I dial the number for Mindy's I'm going to give very long odds indeed against the phone being answered "White House Washington". So I decide to ignore a question being answered with a question, and I say: "How may I help you?"

A customer recently asked how he could get a SPLat working down to a time resolution of 6mS, i.e. shorter than the basic 10mS heart beat we normally use. So what we have done is to create a way of setting the rate at which the SuperTimers tick over. This can now be set to anywhere from 1mS to 255mS. To use the faster settings you would have to make sure your program is very short and tight ... there's no point having the timer period shorter that the execution time of your program. For the slower setting you can now time up to a whopping 49 days in one go, albeit with resolution reduced to 255mS. Documentation.

And here's the customer's reaction.

I am really excited about this.

We have just completed work on a whole new method of interconnecting several SPLat boards into a "very local network". We call it Xwire.

Xwire is a very easy to use, extremely low cost serial peripheral bus. If you have a CC16 or MS120, you may have noticed some 2-pin connectors labeled X1 and/or X2. On the CC16 there are 2 of them (X1 and X2). On the MS120 there is one. You can connect the X1/X2 connectors on a number of boards together using simple twisted wire, and with some very easy programming get the boards exchanging data. In effect, once it is set up with a master controller and one or more slaves, the master can swap nominated bytes of RAM with each slave.

Kim asked:

Hi David

On the Xwire scheme is it possible to have a master and a slave and if the master drops out, the slave becomes the new master ? Like a redundancy type setup.

Also, based on the redundancy scheme, if 2 separate power supplies are used to power each board, what special considerations do I need to take ?

Hi David

I have 5 semaphores declared as

sVeryImportant     defsem   1
sQuiteImportant    defsem   2
sImportant         defsem   3
sLessImportant     defsem   4
sNotImportant      defsem   5

The above semaphores decided which task controls a motor. Obviously only one task can control the motor at any one time.

However, the above semaphores are prioritised and the Very Important semaphore cannot give up the task until its finished its task. And likewise a less important semaphores cannot take over from a more important semaphore, though a more important semaphore MUST take over from a less important semaphore.

Kim (prolific fellow!) asked:

Hi David

Have you got a naming guide that you use for naming task etc ? Are you able to share some of your "hard earned" wisdom ?

Dick asked:

Hello David; I just re-flashed my mmi201i board with V.3.17 which resulted in dialect 18. I was planning to use the instruction fPULSE0 but it can only be used with D=>19. Is there anything I can do to have D19 on my board?

Also, when re-flashing, the panel identified my board as $0040. Where on the board or elsewhere can that number be verified?