Me again

Hi all,
Thanks for the responses to the last question, I think I know what I need to do now.

Basically the outputs I have to read will be logic 1 or logic 0 I believe.

The options I was looking at were:
1. build a microcontroller based device
2. get a data acquisition device from National Instruments or Labjack or something like that
3. connect directly to a serial port

Are these valid options?

spare me, I'm a newbie

I'm a database and gui programmer mainly.
I've been given a requirement as follows:
The client will output 3 alarms to 3 binary switches.
I need to trap changes to the switches and update a database with what switch changed and what state it changed to.
I'd planned using a microcontroller which the switches would input to and which would output to a PC (via RS232 or preferably USB).
I'm getting conflicting accounts of how long it would take to build such a device (1 week to 1 month). I've been playing with a Microchip picKit Flash starter kit for a day or so.
What I want to know is if there's readily available commercial units that would do what I'm looking for or could be customised quiet easily or failing that how long would it take for someone who knew what they were doing to build this?
We'll only need a dozen or so of them.
Are there any resources on the net which might help me?

(no subject)

the traction control is working (with a few minor bugs)!

which now leads me to my next project... or sort of a continuation. i think i'm going to build an electronic ignition controller. its tough to do because an engine is very sensetive to spark advance and retard. especially a turbocharged engine. i hope i dont break anything.

but i'm moving so all projects are on hold for a couple weeks. why move to new jersey? because its better than oklahoma.

oh, does anyone know where i can pick up some cheap servo motors?
beardy beard bearded

PIC programming/IC-Prog problems

Hi folks,
I'm mostly a newbie getting back into microcontrollers. I've done a good deal of low-level hobbying on the BASIC Stamp BS2p-40, and I even once got this PIC-16F84A working more than a year ago (and only that once), but I've forgotten quite a bit about PICs specifically, and now that I'm back into it, I can't get certain things to work, and they're difficult things to search for online - I've tried to no avail.

I'm using the Olimex PG2C, the LED of which I have seen in the past light up when programming/verifying/erasing/etc. It wasn't doing it this time around, and I recall that it wasn't about 6 months ago when I made a half-hearted effort to get back into it. Another problem is that IC-Prog always finds that there's a programmer, even when it's unplugged, and it always writes/verifies/erases with no errors, even if I remove the PIC from the ZIF socket. After much tweaking of settings the other night, I got the LED to blink when I was verifying, and then taking the PIC out, it errored, as it should. I figured it was solved, and moved onto reacquainting myself with the programming and wiring knowledge. I got through enough of that, made a HEX sample, and then it all fell apart again. When I try to load the HEX into IC-Prog, the title bar changes to the path and file, but the hex data doesn't update. The entire program code area remains filled with 3FFF blocks. I've read everything I can find - the entire help file end-to-end, lots of online things and old forum posts. I'm pretty sure I have things set up right - COM 2, PIC 16F84A, all the configuration bits, the HEX file matches the tutorials, JDM programmer with Windows API as recommended by Olimex, etc. It all seems right. Anyone know why the hex data doesn't reflect the file contents, or should it? Maybe that area is only supposed to show the chip's data? I seem to recall this has always been a problem, even when I got the PIC programmed that one time - I just let it program despite the 3FFFs, and the chip worked. BTW, I did try that, and nothing - the PIC seems dead. I've also tried a new, and unused 16F84A - nothin'.

When I attempt to program any '84A, it does the same thing - the Olimex LED does nothing while IC-Prog runs through its progress bars with no problems, and sings the songs of a succesful programming at the end. I have the verify programming boxes, and none of the communication inversion boxes checked, but they aren't noticing that I'm successfully programming an empty programmer. Without IC-Prog's help, I'm kinda stuck right now for getting anything accomplished. I've even updated to the latest version and tried that - no dice. I'm hoping someone's been here and knows a way out, because I don't want to lose faith and give up on microcontrollers again.


Update: Looks like it was my hex file after all. It matched number for number with the sample from "Easy Microcontrol'n" by David Benson, but it's quite a few years old now, and may be too out-of-date. IC-Prog was the real stopping point in the pipeline, but dropping in some randomly-found hex code from a midi sequencer project I found via Google worked beautifully, clearing up all errors. Maybe with some more debugging I'll be able to find exactly what it was that had IC-Prog doing nothing at all with my hex. Thanks all, for the help!
  • Current Mood

Stair Lights

Microcontroller stair lights??? why not?


These lights were inspired by my cat. We have an older cat, and with old age comes a loss of agility, coordination and night sight. At night when the house lights are off I had heard the cat trip on the stairs to the basement. I needed to come up with a method of lighting the stairs at night when the house is dark. I thought that I could install a night light that comes on when it is dark. But this would have been too easy, there must be a more complex way to aid the cat. The end result is my microcontroller controlled stair lights. There is a laser beam at the top and bottom of the stairs, the height of the beams allows it to detect humans as well as our cat. There is an LED installed under each stair tread, this softly lights each stair.


When a beam is broken the lights ramp on, it might look as though they just turn on but there is a soft start algorithm that brings them from off to on quite quickly. There is then a delay to allow the person/animal to use the stairs. The lights then turn off one stair at a time following the person/animal. For example if the top beam was broken to activate the lights the lights will turn off starting with the top stair light. The lights ramp off at a slower more noticeable rate. There is also a small speaker that is connected to the system, the purpose was to be alerted if a small child was attempting to go upstairs. This speaker was mainly used while doing debugging, it has since been padded way down so that it is barely audible since it is not needed. Two buttons on the unit were going to be used to program the device and force the lights on or off. These have not completely been programmed since there has never been an occasion to need them.

(there are mutliple videos showing this hella cool project off at the link. No this was not my project. I wish.)

(no subject)

wow. i started this community a while ago... i thought no one would ever join it.

well, since ive been in oklahoma in training for the air force for about 7 months i havent had any time to play with my micros. until now. my latest project- traction control for my car. i'm using a silabs c8051f350

my program measures the revolutions of the drive wheels and the non-driven wheels. if the difference reaches a certain level (indicating a certain amount of tire slip) it cuts engine spark momentarilly to keep the tires from spinning beyond a rate that can be controlled. the cool part? i have a little dial on the dashboard that i can adjust the amount of traction. there is still some bugs though. i'm at the library right now so i dont have the program but i'll see if i can bring it over on my cool new USB jumpdrive.

thanks for keepin it alive, guys
South Park Me


I'm currently beginning working on an UAV(Underwater Autonomous Vehicle) robotics project.

In the past I've always used Basic Stamps, however I'm beginning to wonder if perhaps PIC microcontrollers aren't a bit more economical and well supported.

The biggest problem I have however (Aside from making the gargantuan leap from regular robotics to underwater robotics, what with all the water proofing). Is I know no one personally that uses PIC microcontrollers, so I can't get a good feel for them.

So, does anyone have any opinions on the Basic vs PIC MCs?

16F84 serial

YES. I'm so excited. I'm new to programing pics, just got back into it. Assembled a 16F84 to output ascii A through a single pin, serially. I know this isn't too hard, and there are already programs out there to do it, and more advanced pics with uarts, but now I can do it myself. Since none of my friends care or know what the hell i'm talking about, i decided to post it here...