View Full Version : is there a systematic way to test the pins on my bs2p24?

08-22-2005, 06:20 AM
long-time reader, first-time question...

i'm just really getting started with my basic stamps and i love it. one thing that has me a little hung-up on a project is this... i am working with a bsp plus pack and i'm trying to get my pcf8583 to keep time.

i've tried a few different schematics/codes that i've found online and i still don't know what time it is!

basically, i'm afraid that i might have damaged a pin on either the RTC or the BS2p... i hope that i'm wrong about that, but when i dissemble the circuit from my board and download the code into the stamp with no components hooked up i get the same debug window as when i'm all hooked up and i run the code (the debug window shows a strange character - probably ascii - when i'm expecting decimal time/date data in the window).

what am i doing wrong?

i'm afraid that it might be the chip (i hope not) because i recently purchased an sht-75 on ebay and i'm having similar difficulties with that (btw - all the datasheets that i've seen for the sht-7x show a single in line four pin thing and the one i got is a surface mount sensor that has eight pins in a dual in line design, four on each side. this is confusing enough, but the fact that the pin arrangements for the sht-1x's - the surface mounted sensors - and the sht-7x's are different makes it hard for me to tell which pin arrangement works for my model).

also, i'm a little unclear as to how the built-in 4.7k resistors on my BS2p24/40 rev. b demo board work... i have read the documentation and i get the impression that when the jumpers are on JU1 and JU2, the four inputs on the X6 strip (two of which seem to be labelled iB1 and two seem to be iB2) route through the 4.7k resistors to the Vdd... am i way off here? can i make FOUR different connections to the +5V through the 4.7k resistors on JU1 and JU2?

i am a neophyte in the world of basic stamps and i hope i'm just making silly mistakes... if anybody has a simple schematic/code for either the sensirion sht-75 or the pcf8583 (i don't have an LCD so i'm using the debug screen) please let me in on it.

one other thing, this is my first post so i have to (at least once) thank everybody on the forum and the people at parallax for being such a great information resource. it is truly an inspiration to check out the site and see what's happening so keep up the great work!


08-22-2005, 10:15 AM
As you're topic specifically requests a way to systematically test all of the pins on the BS2P40, there is a way. It requires you to either create a daughter board, or breadboard up some cap's, resisters, and some jumper wires. It'd be much better to just invest the time and create a stamp tester. Here's the link to a thread of many of the board's regs talking about creating one. There is schematics, and code there for anyone to create their own.

As for the rest of the questions, they are mostly specific to the BS2P40 Test board, and I am completly unfamiliar with it, as I use just a standard breadboard for my BS2P40. So hopefully some of the regs will chime in and help you out on those other questions, as I just don't know enough to be of any help in that respect.



Chris Savage
08-22-2005, 10:37 AM

The connections on the X6 header are for the Phone-Jack (RJ11) plug on the end of the board, as well as the Battery-Holder looking socket, which is for an iButton. Yes they are connected to Vdd when the jumpers are installed, but I'm not sure you're using them as intended. How is your circuit wired?

Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

08-22-2005, 01:15 PM
first of all, i've tested all my pins with a simple LED program going through each of them one at a time and, luckily, everything is okay there. i've tried a couple different circuits without working on just one so i'm going to have to just choose one and work it through.

but as far as how i'm using the X6 header specifically, i'm connecting to either of the iB1 or either of the iB2 as though they were a 4.7k resistor that was connected to Vdd (i see JU1 and JU2 and i guess i'm thinking that they are onboard resistors accessible to non-iButton circuits...)

08-23-2005, 12:27 AM
okay, i admit that my first question was kind of all over the place. at this point, i'm just trying to wrap my mind around how to use the built-in 4.7k resistors on my bs2p24/40 demo board (rev b.)

Chris Savage
08-23-2005, 12:40 AM

They are there primarily for connecting Dallas iButtons, but I guess you could use them for something else.

Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

08-23-2005, 12:58 AM
Taylortronic, have you tried a Stamp Tester?

Sid Weaver
Do you have a Stamp Tester yet?

08-23-2005, 05:58 AM

i ordered it and it's on the way. i can't believe i never came across that web page before... what a useful tool.