Search found 1754 matches

by riden
Thu Feb 25, 2010 4:01 pm
Forum: SparkFun Product Questions
Topic: my wine cooler
Replies: 10
Views: 908

millis() is driven by an interrupt so delay() shouldn't be an issue. The simplest delay is a series of tight loops which the timer will periodically interrupt. Be sure to let us know if you get better timer results.

Edit: Egads, I just found an issue with the code I posted. I'll fix it.
by riden
Thu Feb 25, 2010 1:54 pm
Forum: SparkFun Product Questions
Topic: simple vibration/impact switch
Replies: 3
Views: 1794

The following sensor works very well in these types of applications and would be preferable to a mercury switch (mercury is a toxic heavy metal). You could also roll your own sensor like lyndon suggested.

http://www.signalquest.com/sq-sen-200.htm
by riden
Thu Feb 25, 2010 12:00 pm
Forum: SparkFun Product Questions
Topic: 3.5mm Audio Jack -- shorts the inputs when plug is inserted
Replies: 29
Views: 4585

I think that we can conclude that the problem is caused when both outputs of the device are momentarily connected to each other, the ring is momentarily connected to the shield (shorting one channel to ground), or a combination of both conditions. The MAX4410 has short circuit protection. My guess i...
by riden
Thu Feb 25, 2010 7:53 am
Forum: SparkFun Product Questions
Topic: 3.5mm Audio Jack -- shorts the inputs when plug is inserted
Replies: 29
Views: 4585

The problem in my project is not audio quality, but rather that when inserting the headphones plug, the shorting of the left and right channel inputs causes a brown out condition. I have a few questions: 1) If you have the power off, plug in the headphones, and turn the power on, does it work as ex...
by riden
Thu Feb 25, 2010 7:15 am
Forum: SparkFun Product Questions
Topic: some weird effect of Telephone DTMF MT8870CE !!!
Replies: 8
Views: 1108

vinodquilon wrote:Not INH pin, but PWDN pin of 8870 should be used for enabling 8870 after off-hook. INH only inhibits the detection of alphabet characters.
Thanks for the correction. I confess that I didn't consult the datasheet and assumed that it inhibited the detection. :oops:
by riden
Thu Feb 25, 2010 7:08 am
Forum: PIC Microcontrollers - Software and Hardware
Topic: rookie getting started
Replies: 4
Views: 746

That board looks an awfully like this one: http://www.sparkfun.com/commerce/product_info.php?products_id=762 Have a look at the links on the SparkFun catalog page. They have a lot of good information about how to use these boards including some Liberty Basic programs to interact with the board. That...
by riden
Wed Feb 24, 2010 9:47 pm
Forum: SparkFun Product Questions
Topic: 3.5mm Audio Jack -- shorts the inputs when plug is inserted
Replies: 29
Views: 4585

I checked continuity between pins 2 and 5. When no plug was inserted, the resistance was infinite (humor me). When I inserted the plug into the jack, there was a point when pin 2 was shorted to pin 5 -- the resistance dropped to 1 (one) ohm -- then went back to infinity after insertion was complete...
by riden
Wed Feb 24, 2010 8:45 pm
Forum: SparkFun Product Questions
Topic: 3.5mm Audio Jack -- shorts the inputs when plug is inserted
Replies: 29
Views: 4585

After following this thread for a bit, I decided to take one of these connectors and make some measurements. Referencing the data sheet that the OP provided, I can confirm the following information: 1) Ground (sleeve) is pin 1 2) Tip is pin 5 3) Ring is pin 2 These are exactly as described in the da...
by riden
Wed Feb 24, 2010 8:19 pm
Forum: SparkFun Product Questions
Topic: some weird effect of Telephone DTMF MT8870CE !!!
Replies: 8
Views: 1108

I'm not sure exactly what you want to do, but I think you want to be able to call into this device and have it decode your DTMF tones sent by the caller. If that is the case, the device should only be activated when the phone is answered. This presumes that your device isn't doing the answering. If ...
by riden
Wed Feb 24, 2010 2:47 pm
Forum: SparkFun Product Questions
Topic: Do I need an amplifier?
Replies: 14
Views: 2399

STMMicroelectronics use to make 1 to 2 watt single chip stereo amplifiers, but I don't know what is currently available.
by riden
Wed Feb 24, 2010 2:03 pm
Forum: SparkFun Product Questions
Topic: Do I need an amplifier?
Replies: 14
Views: 2399

Yes you will need an amplifier. An LM386 based amplifier should provide a low cost solution for you.
by riden
Wed Feb 24, 2010 1:36 pm
Forum: SparkFun Product Questions
Topic: some weird effect of Telephone DTMF MT8870CE !!!
Replies: 8
Views: 1108

Re: some weird effect of Telephone DTMF MT8870CE !!!

vinodquilon wrote:The problem is that, When I calling from remote end all the LED s blinking randomly for 1 sec (undesired result) and then
comes to a stable state.
Caller ID signaling?
by riden
Wed Feb 24, 2010 10:33 am
Forum: SparkFun Product Questions
Topic: SN754410E woes
Replies: 11
Views: 2797

I'm a dunce. Sorry, should have gone to bed earlier. :oops:

According to the TI datasheets, both the SN754410 and L293D have the internal protection diodes. The L293 does not and would require external diodes for protecting the chip.
by riden
Wed Feb 24, 2010 7:27 am
Forum: SparkFun Product Questions
Topic: electronic component to switch between 2 signal sources
Replies: 4
Views: 348

You could use a hex inverter like a 4069 to invert the logic levels or if you are driving the 4066 from a microcontroller, simply invert the logic in software.
by riden
Tue Feb 23, 2010 8:37 pm
Forum: Wireless/RF
Topic: Looking for Cheap Hack
Replies: 4
Views: 671

I would be interested in other views, but I don't think you are going to be able to do this satisfactory for less than $20-25 per button on the low side. The big challenge is mitigating collisions caused by everyone buzzing in at the same time is such a way that the system is responsive. The low cos...