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Make you own power line interface and send the data however you want:<p>
Philips

This chip has 4 pins labeled ROW and 4 pins labeled COLUMN each has an internal 40K pull-up resistor.<p> NTE1690 <p>The data sheet says that one row pin and one column pin must be grounded to send tone. <p>A standard 3X4 grid keypad simply shorts together one row and one column when a key is pressed...

Would a consumer device that uses only 3 AAA batteries, 3 push buttons and a custom LCD require FCC approval? The microprocessor is the TI MSP430F413 and the crystal is 32,768 KHz. Thanks.

The main components are (2) AA batteries operating a pic micro (16f628). I don't want an led on when the batteries are new to conserve power. I do want it to come on when the batteries get low (even though this means faster battery drain). Possibly I could pulse the led on/off to conserve power. <p>...

I need a battery test circuit with as few components as possible. I just want to test 2AA batteries in series and turn on an led if they are < 2.5V.

I love BASIC.<p>I used to fear C.<p>Until I tried C. If you know BASIC, you can do wonders with C. I was amazed a how similar the two languages were. I taught myself C in about a week and I haven't used BASIC or Assembly since.<p>With that said, www.ccsinfo.com makes a good C compiler for Microchip....

I have developed and tested a new position sensor for large farm irrigation equipment that indicates the position of the equipment in degrees and sends this data to our computer main control panel. It works great and sends data to the panel using RS485 serial. <p>I have some customers who want to re...

The micro does a lot more than just react to the sound but sound is one of the inputs I need. I want it to go to the analog input so in the future I can look at the relative sound level to do other tricks.... (it's a toy dog thing for my kid. It used to have a cabled remote control with 5 functions ...

At some time in history, I saw a simple electret microphone amplifier that connected direct to an analog (0-5V) input of a microprocessor. Does anyone have a link or example of this drawing? I want very simple sound activation (any sound louder than a whisper) Thanks.

I got a suggestion to use a DC/DC step up converter like LM2703 or MAX1674. Anyone with any experience with these? It looks like the LM2703 will use more battery current when the processor is asleep. MAX1674 looks best but I hear bad things about supply/delivery/price.

Put a 750K resistor from a microprocessor input to +5. Now put a stripped wire to the processor input and lay the other end where you want to detect water. Now put another stripped wire from ground to near the other stripped wire. This works on a pic. You should see a simple high/low when dry/wet.<p...

Thanks everyone. I bought a demo board from www.softbaugh.com (BLCDA4) that I am using to do the programming. It is very similar to what our final product will look like so I can test battery life and regulators with that board. Currently, it is drawing 99uA while displaying data on the lcd. We will...

I should have said 3 AAA batteries (typo in previous post) The customer wants the batteries to add weight to the device. Voltage is still the same as AA. I am planning on using a TPS76933 3.3V regulator.

I need to power a MSP430F412 project with 3AA batteries. This adds up to 4.5V and the MSP has a max of 3.6V. We want as few components on this board as possible. Would you use a regulator or 2 diodes in series to drop the voltage? This board only has a custom lcd, 4 pushbuttons and the batteries. Th...

The speaker is an 8 ohm, 150Watt, Horn type speaker/driver made by Selenium (sp).