NX1000's DS1307 grief

nick bernard · 2004-11-18 15:22

HAIL ALL,
i have DS1307.BSP running on a bs2p on my nx 1000 board
i have it wired as:
pin 0 -> SDA
pin 1 -> SCL
pin 4 -> D0 - switch
pin 5 -> D1 - switch
pin 6 -> D2 - switch
pin 7 -> GND

the debug screen displays

DS1307 Demo

65:65:65

my scope sees
0v on pin1 of the ds1307
5v on pin2 of the ds1307
0v on pin1 of the ds1307
5v on pin5 of the ds1307
5v on pin6 of the ds1307
0v on pin7 of the ds1307
5v on pin8 of the ds1307

any help?

rox on
nick bernard

Bruce Bates · 2004-11-18 15:50

Nick -

If you're looking at the same program (DS1307.BSP) that I am, which was originally found on the High-TechGarage web site, you will note that the EEPROM "switch" needs to be reset for the first run of the program, and anytime thereafter when you want to have the program initialize the real time clock. This should help with that issue:
http://www.gorobotics.net/articles/article.php?name=realtimeclock

Note: It appears that High-TechGarage is no longer in business under that name.

Regards,

Bruce Bates

nick bernard · 2004-11-18 16:03

HAIL BRUCE!

thx for the input yo, i got the program from the parallax site though. supplied specifically for the nx1000 board. in any case your input seems applicable and i'll give it a shot.

rox on
nick bernard

nick bernard · 2004-11-18 16:35

i've tested all the i2c devices on the nx1000 and none of them seem to work.... wo is me

nick bernard

K de Jong · 2004-11-19 00:26

Hi Nick,

Do you have pull up's (4k7) on SDA and SCL ??

Klaus

nick bernard · 2004-11-19 14:24

yes... the nx1000 has them on the protoboard.

i dont pick up any activity after i simply put a pullup (47k) on pins 0&1, (sda scl)... i figured there would be some signal movement with the i2c commands.

but even if the i2c interface is failing then why doesnt the sqw pin on the ds1307 oscillate?

you can find the soucecode that i'm running on the parallax site
www.parallax.com/detail.asp?product_id=28137

thx
nick bernard

Tracy Allen · 2004-11-19 17:12

The sqw pin does not run until you enable it with a setting in register 7 of the DS1307. Also, sqw requires a pullup resistor.

The demo program has lots of bells and whistles. When I am confronted by something that doesn't work, I like to strip it down to the bare essentials.

  {$STAMP BS2P}
  {$PBASIC 2.5}
   seconds var byte

    I2COUT 0, $D0, 0, [noparse][[/noparse]$00, $00, $00, $00, $19, $11, $04, $10]
         ' should start the clock running setting Nov 19, 2004 at midnight
         ' sqw enabled at 1 Hz byt the $10.
  DO
      I2CIN 0,$D1,0,[noparse][[/noparse]x]   ' read seconds
      DEBUG Hex2 seconds, TAB, BIN in2,CR
      PAUSE 250
  LOOP

That program uses in2 to read the state of the sqw pin. To do that, pin 3 of the DS1307) has to be connected with a pullup resistor, say 10kohms, to Stamp p2. With that program you should see activity from your 'scope on p0, p1 and p2. The sqw pin should have a period of 1 second as seen on the DEBUG screen and on the 'scope. Yes? No?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com

NX1000's DS1307 grief

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