Using the DS1302 real time clock with the STAMP PLC with Javelin Stamp as proce

Kweku

Hi There,
I would like some help on how to connect the DS1302 IC to the STAMP PLC and Configure it to work with the STAMP PLC using the Javelin stamp as the processor.
Thanks,
Kweku

Post Edited (Kweku) : 12/12/2006 8:14:52 PM GMT

Peter Verkaik

http://www.parallax.com/javelin/applications.asp#AN002
regards peter

Chris Savage

Kweku,
·
·· Peter has linked you to the DS1302 AppNote for the Javelin, and that will help you in using this RTC with the Javelin itself, however if you are using the Stamp PLC you won’t be able to connect the DS1302 to this system due to the way the I/O pins are pre-configured.· Each I/O pin is an isolated input or output.· The outputs are connected to current drivers.· The DS1302 would require 3 I/O pins directly from the module that weren’t connected to anything else.· I hope this helps.· Take care.

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Chris Savage
Parallax Tech Support

Kweku

Thanks alot. I still need to be able to tell the time using the STAMP PLC is there any other device you know of i can hook to the PLC to get the time and date?

Thanks,

Kweku

Peter Verkaik

According to the PLC manual page 12

'

---

[noparse][[/noparse] I/O Definitions ]

---

Clock PIN 0 ' shared clock
Ld165 PIN 1 ' 74HC165 load
Di165 PIN 2 ' 74HC165 data in (from)
AdcCS PIN 3 ' ADC chip select
AdcDo PIN 4 ' ADC data out (to)
AdcDi PIN 5 ' ADC data in (from)
Di9 PIN 6 ' direct digital inputs
Di10 PIN 7
DOuts VAR OUTH ' direct digital outputs
DOutsLo VAR OUTC ' -- Do5 - Do8
DoutsHi VAR OUTD ' -- Do1 - Do4
Do1 PIN 14 ' updated 21-DEC-03
Do2 PIN 15
Do3 PIN 12
Do4 PIN 13
Do5 PIN 10
Do6 PIN 11
Do7 PIN 8
Do8 PIN 9

so it looks as if CPU pins 6 and 7 (direct digital inputs Di9 and Di10) could be used.
I don't have a schematic so be sure to check wether anything (leds, pullups etc)
is connected. If there are just pullup resistors connected then
you could use P6 and P7 for an I2C bus and then use a DS1307 rtc instead of DS1302.

Edit: just noted on the product page that all digital inputs are opto-isolated.
This means even P6 and P7 cannot be used unless the opto circuitry is disconnected.
You could leave P6 and P7 pins out of the socket and solder wires directly
to P6 and P7. You can then use P6 for SDA and P7 for SCL. Connect 4.7k pullup
resistors to P6 and P7. Di9 and Di10 are then no longer available.

regards peter

Post Edited (Peter Verkaik) : 12/21/2006 1:35:43 AM GMT

Peter Verkaik

Here is an adaptation of the StampPLC.java demo program.
It supports the DS1307 connected to javelin I/O pins 6 and 7.

regards peter