Time clock for RFID entry system.
The project is an entry and exit Log for a shop in a college. We are using the Parallax serial RFID reader, along with a parallax LCD display, and a parallax internet burner kit, (PINK). the student use there RFID cards to enter the classroom and the netburner logs there time of entry on the network for the teachers to monitor.· Is it possible to use the networks clock to send the time·from the computer through the netburner to·the serial display? If so what would be the best way to go about doing this?
Comments
Alternatively, you could add a real time clock to the Stamp setup. SparkFun has a nice DS1307 "breakout board" complete with a backup battery and there are examples on the Parallax website of the use of a DS1307.
Secondly, I understand that the DS1307 uses the SCL and SDA pins to interface with the BS2, what I am confused about is how, or more directly, what the syntax is used by the BS2, with PBASIC 2.5, to read and/or set the time.· We have this IC, using it is another story.
Thanks in advance
A couple of suggestions…regarding the current time and getting it from the network to the LCD…if you really want to send the server time to the PINK module it must be sent as a UDP message to the PINK Module’s IP address at the correct port. The BASIC Stamp can detect the flag indicating a UDP message has been received and update the display accordingly.
My own personal preference is the DS1302, which has a simple SPI interface to the BASIC Stamp module. It also has a battery backup for both the RTC and the 30+ bytes of RAM on board in case of power failure. Unfortunately there is no way to serially update the flash memory on the PINK. That can only be done through the modify variables page. Take care.
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Chris Savage
Parallax Engineering
Google for Network Time Protocol, this is a method of obtaining the time from a time server over the internet. However, you can use PINK, you have to use something like the X-port which is much more complicated.
Another angle is to use the WWVB radio signal. I just ordered the parts for this yesterday and will be writing code to support this on BS2.
http://www.c-max-time.com/products/showProduct.php?id=31
This chip and antenna receive a time signal for the US atomic clock (similar versions available for other countries) and you could use that to set the DS1302 or DS1307 RTC in a reliable fashion that would be really hard to hack.
If this is just a learning project, and not being used to really secure assets, then use the PINK. Its a great way to learn how http, html and basic internet packet processing works without getting bogged down into the details of IP and Ethernet networks.
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Chris Savage
Parallax Engineering
Also, I just re-read my original comment and I mistakenly put a "not" in my first sentence...in fact it should say that the PINK *will allow* you to send arbitrary packets....at least UDP packets.
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Chris Savage
Parallax Engineering
I sincerely appreciate the help thus far!
Thanks all,
Spicer
I am sure what I am about to say will be controversial, but having been in the internet security business for many years, I have to point out that any assumption that a network is not accessible is very hard to substantiate.
There is no network that is not accessible. Take for example the Pentagon...
http://www.govexec.com/story_page.cfm?articleid=39456
or TJMaxx, which was hacked from the comfort of a car in the parking lot...
http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=199500574
"It's likely that the cyber attacker or attackers who stole millions of customer records from TJX stumbled across a vulnerable store location while staking out a strip mall or shopping center from their car using a laptop, a telescope antenna, and an 802.11 wireless LAN adapter."
Granted, your school may not be tops on the list of places to hack...but other people reading this forum may be in situations where they should be considering the security implications. The Internet is a dangerous place.