Search found 373 matches

by psycho
Sun Mar 14, 2010 11:18 am
Forum: General Discussion
Topic: Funky Pot Problem
Replies: 12
Views: 1905

Re: Funky Pot Problem

You have all pretty much confirmed my suspicions... I will just replace them and be done with it. I couldn't understand why BOTH of the pots would be dead but then I thought... Well, there is a reason someone gave it to goodwill... The other two pots seem to be OK but I will get a half dozen of them...
by psycho
Sat Mar 13, 2010 4:19 pm
Forum: General Discussion
Topic: Funky Pot Problem
Replies: 12
Views: 1905

Funky Pot Problem

I went to Goodwill a couple weeks ago and picked up an old racing wheel with a joystick (15 pin dsub) connector. My intention was to use a uC (PIC18F2550) to convert it to USB. It worked out great except for one thing... For $6, it came with the two floor pedals. It has a total of 8 buttons (on the ...
by psycho
Thu Mar 11, 2010 1:42 pm
Forum: General Discussion
Topic: Switching High voltage high amp DC
Replies: 3
Views: 735

Re: Switching High voltage high amp DC

I am not sure exactly what your project requirements are but since you said microcontroller *and/or* switch... A uC may not be needed. If you get a 4 position rotary switch (or 5 if you want an off position), you could use 12v for the switch to control 4 relays. This would be much more straight forw...
by psycho
Wed Mar 10, 2010 6:27 pm
Forum: Computer Programming
Topic: USB Switch problem
Replies: 6
Views: 1651

Re: USB Switch problem

I make USB devices all the time (although they are not the highest speed - tho they are 2.0 - don't remember exactly which speed - full??). I have not run into this problem but I know that shielding is a bigger factor the higher the data rate is. If it were me, I would try better shielded cable firs...
by psycho
Mon Mar 08, 2010 6:04 pm
Forum: General Discussion
Topic: Jameco 664 EPROM Programmer
Replies: 9
Views: 1865

Re: Jameco 664 EPROM Programmer

If nothing else (provided you get Nuts & Volts), you can put a question in the tech forum in there. A lot of people read that magazine and someone may know a little about it.

I haven't used an EPROM in 20 years or so...

Kevin
by psycho
Mon Mar 08, 2010 2:16 pm
Forum: Computer Programming
Topic: BoostC
Replies: 7
Views: 3579

Re: BoostC

And also the MPLAB download comes with an assembler/linker. If you are not looking for the highest optimization, you can use the free version forever - I am sure there are restrictions on making a product for sale - you wwill have to read the fine print. But for the average guy just learning, you wi...
by psycho
Mon Mar 08, 2010 12:51 pm
Forum: Computer Programming
Topic: BoostC
Replies: 7
Views: 3579

Re: BoostC

I don't know about BoostC but, being someone who has used PICs for a long time, I would get a Microchip compiler instead. They have free versions - most of which are not time limited but rather, limited in the optimization after 30 days. They have excellent support and you can bet that any new devic...
by psycho
Sat Mar 06, 2010 1:26 pm
Forum: General Discussion
Topic: Audio Preamp???
Replies: 3
Views: 858

Audio Preamp???

I use a cheap pair of amplified PC speakers plugged into my MP3 player to listen to music in my electronics workroom. With the speakers turned up all the way and the MP3 player up quite a bit, it is still not very loud. What I need is more volume on the cheap. If I made a preamp and put it inline be...
by psycho
Thu Feb 18, 2010 9:01 pm
Forum: General Discussion
Topic: lm3919?
Replies: 40
Views: 6101

Re: lm3919?

I believe pins 6&7 need to be connected - IIRC, they are feedback voltages or something for the chip. I can't look right now because I am busy as a beaver...
by psycho
Wed Feb 17, 2010 10:32 pm
Forum: General Discussion
Topic: lm3919?
Replies: 40
Views: 6101

Re: lm3919?

Oh, and are you still getting a voltage reading on the negative side of the voltage divider??? If you are then you do not have it connected to a proper ground - there must be some resistance between it and ground.
by psycho
Wed Feb 17, 2010 10:29 pm
Forum: General Discussion
Topic: lm3919?
Replies: 40
Views: 6101

Re: lm3919?

The size of the resistor on pin 7 controls the brightness of the LEDs (current limiting resistor). If you have a breadboard, plug the two resistors in and make the divider - that way you will understand how they work and how to test them. The way the guy is using the chips is more complex than you s...
by psycho
Wed Feb 17, 2010 10:07 pm
Forum: General Discussion
Topic: lm3919?
Replies: 40
Views: 6101

Re: lm3919?

Once you have the voltage divider working, take the center tap and hook it to the input of your circuit. All a POT is is a voltage divider. By turning the knob, you change the ratio of the resistance of the pot. Think of it like two variable resistors with a tap in the center. One leg goes to ground...
by psycho
Wed Feb 17, 2010 9:51 pm
Forum: General Discussion
Topic: lm3919?
Replies: 40
Views: 6101

Re: lm3919?

If you are working on a breadboard, plug one end of one resistor into Vcc. Plug one end of another (same resistance) resistance into ground. connect the free ends of the resistors together. Use a meter and put the black probe to ground and the red probe on the junction of the two resistors and you s...
by psycho
Wed Feb 17, 2010 9:09 pm
Forum: General Discussion
Topic: Liquid tin
Replies: 7
Views: 1028

Re: Liquid tin

So, the next question would be... What is the best way to plate through holes/vias (please don't say to solder both sides or put small pieces of wire in the holes - I already know about those ways). How do board houses do it? It's probably too hard to do at home :(

Kevin
by psycho
Wed Feb 17, 2010 7:39 pm
Forum: General Discussion
Topic: Why has Chuck Hellebuyck's Column Been Cancelled?
Replies: 4
Views: 1059

Re: Why has Chuck Hellebuyck's Column Been Cancelled?

I didn't know it was canceled. How did you find that out? I believe it only ran every couple of months. His was the "Getting started with PIC's", right?

Kevin