View Full Version : breadboarding a bs2.. want to eliminate reset surervisor..
ok i thik i have it all together except for what to do with pin 28 of the interpreter?? can i use a 2n3904 with base connected to pin 4 of db9 through a 10k resistor and a 10k resistor frombase to emiter with emiter connected to grnd, and collector connected to pin28 of interpreter and vdd through 4.7k..
i have found several scematics out there and some show this way but also include the reset supervisor connected to pin 28?? can i just leave it out??
no takers yet.. maybe i'll hook it up and hope i dont let the smoke outa it..
09-01-2008, 07:38 AM
The datasheet explains a bit about the reset supervisor's function:
The MN1380 series are elements that monitor the power
supply voltage supplied to microcomputers and other LSI
systems and issue reset signals for initializing the system
after the power is first applied or for preventing runaway
operation when the supply voltage fluctuates.
09-01-2008, 11:33 AM
The following thread covers BS2 OEM designs, including with and without the brownout detector.
Thanks chris , iknew i saw this post before but couldnt find it.. it still dosent answer my question but it is a very helpful thread.. my design is the same as oem but no reset supervisor.. thinking of going with the max232 option instead..
09-02-2008, 10:56 PM
I’m not sure what more there is to answer in your question…The MCLR line always needs a 10K pull-up. All the reset supervisor does is hold the chip in a state of reset if the voltage drops below the rating of that device. It does this to protect the EEPROM from being corrupted during very low voltage. If your power supply isn’t likely to be running below 4 volts then you can probably do away with it. It would be more important in a battery operated system where the voltage would continue to drop over time If left on.
there it is!!!!!! 10k pullup on mclr.. i think i should have specified What to do with mclr? anyway thanks ill try it with 2 npn transistios and 1 pnp, if i dont get it to work ill wait for caps and use max 232.. im not too experianced with electronics but every day i learn something new and every day something old make more sense..
09-03-2008, 02:56 AM
Yes, the 10K is required regardless of whether or not the Reset Supervisor is installed. Either way I am glad that helped. Take care.
this is the diagram im using.. minus U3.. plus 10k pullup in its place?? see any problems??
09-03-2008, 04:38 AM
Your schematic already has a 4.7K pull-up so you can just use that.
ok and Sin...serial3, Sout serial2, atn serial 4 and grnd to serial 5.. right?
09-03-2008, 04:54 AM
Okay, you just lost me...The 4.7K resistor was already in your circuit connecting to the /MCLR line and to 5V. It is also part of the circuit around Q2, which also resets the BASIC Stamp based on the DTR line. Where are you getting serial3, serial2 and serial5?
just checking to see iff my other connections are correct
09-03-2008, 05:09 AM
Okay, I think I see what you're referring to...serial2, serial3, serial4 and serial5 are actually the connections to the pins on a DB-9 serial cable. If so, then yes, they are correct.
thats what i have and when i try to identify i get loopback yes echo yes· no stamp found.. ill check my wiring again.. maybe i have a transistor backwards or something.. thanks for your help Chris
09-03-2008, 05:34 AM
Are you using a blank PIC chip, or did you purchase a programmed interpreter from Parallax?
i bought the oem stamp kit.. built it, it didnt work.. so after removing the transistors to test them(witch they tested out fine), i went to radioshack and bought more transistors and put it all together on a breadboard.. i get the same results from breadboard as i did from oem kit.. i dont think i could have dammaged the IC's cause their socketed and therefore not exposed to heat or static from soldering.. also took precautions such as antistatic mat and wristband..? maybe something happened in the mail.. i have been in touch with tech support and they wanted me to send them a high resolution picture but i dont think it would help. i will let them know that i put the interpreter and eeprom on a breadboard and had same results.. other than that i might get another interpreter and plug it into my breadboard just to see what happens. again thank you for you time..KB1NRB
09-03-2008, 05:14 PM
They probably want a high res picture to ensure that you hooked everything up right. Sometimes its very easy to flip a line or mis plug a componet. The first thing they, or anyone IMO would do is make sure you wired everything right.
09-04-2008, 01:08 AM
I·could have damaged the IC's cause their socket ed and therefore not exposed to heat or static from soldering..
I have put many of these kits together and I NEVER had one that did not work
or could not get it to work
I am NOT trying to mean here or Be Little you in ANY WAY
So Please do not take this the wrong way
All I want to do·here is to help you to get this board to work
Did you read the data sheets that are for putting the kit together
If you can buy a Temperature Controlled Soldering Station very help full
I use the data sheets every time·I put one together
Did you use the sockets that came with the kit
Use the sockets that come with the kit this very help full in keeping IC
chip from getting heat damaged
If you did not you should have it make it easier to trouble shooting the board
·The Dot on the Resister Network goes the square on the board·I did this once also and it did not work
Then ·Q3, Q1, U3, Q2· make sure that they are facing the right way and the right part in the right place
I have put these in the wrong place before to and caught it before I solder·them
Then ·IC1 , IC2 The cut out on the chip faces the same way the·cut out shape drawn on the board
The flat side of the·regulator faces the D9 programing port
·Then the ·cap facing the right way the one by the regulator
·These are Most Importance Thing to Get Right
One more thing some of the traces on the board are very thin and if you bend
your components lead down you can damage the trace this not a good thing to do leave them pointing up
I really hope that you can get it to work
··Thanks for any·http://forums.parallax.com/images/smilies/idea.gif·that you may have and all of your time finding them
Post Edited (sam_sam_sam) : 9/3/2008 5:39:14 PM GMT
Thanks for the reply sam.. i would never assume that anyone here was trying to belittle me..(even if they were it wouldn't bother me).. im kinna out of commision for now.. last night i broke one of the leads off of my 20mhz resonator.. as for sockets i, i did use them and they were the ones that came with the kit.. then i took the resonator and interpreter and eprom and tried to get them going on a bread board but no luck.. for now my hands are tied because i dont have another 20 mhz resonator, but when i get one ill give it another go.. i will win nomatter how long it takes.. i messed with a few ics for months before, and always got them going in the end.. thanks again for your input..
OK i got it working.. new resonator and it took off.. loaded simple program
DEBUG " Hello, I'm Your Basic Stamp"
run it and get H followed by a pause then another H.. this repeats until i disconnect power.. any ideas??
09-23-2008, 09:42 AM
It means there's not enough power. The Stamp runs for a little while, exhausts the power supply, resets, the power supply recovers briefly, the Stamp starts all over again. This typically happens when you run it off an almost exhausted battery.
In your situation, it could mean that there's something wrong with the reset circuitry.
Thanks mike thats what i figured was going on so i connected my 5v regulator to a 12v switching power supply.. still have same results.. getting late now so i'll check my reset circutry tomorrow.. thanks for your time its nice to have a well seasoned stamper to advise me
I didnt find any obvious problems.. I have no brownout detector so the reset circuit is as simple as it gets.. +5v to pin 28 of interpreter. im thinking that i might have a bad connection somewhere so im moving every thing to a brandnew bread board.. also thought maybe there was a problem with lm7805 im using for +5v.. so i tested it and get nice steady 5.03v so i dont think this is the problem either..
heres the latest... New bread board same circuit as earlier post, i got the stamp to identify once and then tried to load a program into it and got no stamp found.. so with every thing still hooked up i again tested voltage to stamp.. results are +4.93 volts.. could this be my trouble?? if so i have a few lm317t around i could crunch the numbers and adjust this bad boy anywhere from 2 to 32 volts.. Sorry it takes so long for me to respond.. i have to juggle the breadboard the computer and a very high voltage 2 year old boy..hahaha
the good news is the UPS man dropped of a spankin new BS2px module!!!
SOLVED!!!! i had pin28 of interpretor pulled high and also pulled high through the transistor on atn line of serial connection. removed jumper from vdd to pin 28 and BAM off she goes... also put a capacitor in from +5v to grnd.. Now i think everyone can breathe a sigh of relief and this thread can rest in peace!! Thank you to all those who tried to help and all of your comments were taken into consideration.. without your help i would have given up and this stamp would have lived a lonely life in some box!! THANK YOU!!!
P.S. I will take a pic of bread board, if anyone wants to see it i will post it for you..