UberNewbie can't set his clock...

[Byte_Butcher]

Sigh, well I seem to have a new problem. Although I'm obviously able to read/write to the DS1302 in "burst" mode, I seem to be having a problem addressing individual registers.

For instance, I need to turn the trickle charger on...
I *thought* it was as simple this:

        rst = 1

        'Set Battery charger on and set to "1 diode, 2Kohm"
        Shiftout IO, SCLK, LSBFIRST, [$90, $A5]  ' Set charger   [$90, $A5] 
 
        RST = 0

But that doesn't seem to do it for me.

Anyone got the patience to help me along a little further....

p-p-p-please?

Thanks!

Steve

[Archangel]

Hi Steve, check uot pages5/ 6 of this data sheet, it says: DS 1302 powers up with trickle charger disabled and only a pattern of 1010 will enable charger. http://forums.parallax.com/forums/attach.aspx?a=26594 HTH

[Byte_Butcher]

Thanks Joe,
You can't imagine how many times I've read the data sheet.... (it's been open on my desktop for days now)
I'm clearly not quite understanding yet.

Yes, a pattern of 1010 turns on the charger, and the other 4 bits of the byte set the charge rate.

So what ( I think) I want to send is 10100101 which should tun on the charger and set it to "1 diode, 2Kohm" operation. In HEX, that's $A5, right?

So I've sent $90, which should be the register address for the charger, and $A5, which should be the code to turn it on and set it to my chosen charge mode. I even tried sending the data in binary, like so:

        rst = 1

        'Set Battery charger on and set to "1 diode, 2Kohm"
        Shiftout IO, SCLK, LSBFIRST, [$90, %10100101]  ' Set charger   [$90, $A5] 
 
        RST = 0

but with the same (no) result.

What am I doing wrong? (please!)

Thanks,
Steve

[Byte_Butcher]

Ahh, never mind, I figured it out...

Setting up the trickle charger is the first task task I ask of the DS1302, and I just needed to pull the reset line LOW first, before I yank it high and move the data.
All I was missing was "rst = 0" up front:

 
       rst = 0
       rst = 1

        'Set Battery charger on and set to "1 diode, 2Kohm"
        Shiftout IO, SCLK, LSBFIRST, [$90, %10100101]  ' Set charger   [$90, $A5] 
 
        RST = 0

Thanks again to everyone!

Steve