Search found 1754 matches

by riden
Mon Mar 01, 2010 10:14 pm
Forum: SparkFun Product Questions
Topic: 3.5mm Audio Jack -- shorts the inputs when plug is inserted
Replies: 29
Views: 4588

Re: 3.5mm Audio Jack -- shorts the inputs when plug is inserted

One thing I noticed in the MAX4410 datasheet is a sentence about the soldering profile. It says that hand soldering is not allowed. I suppose it is possible that hand soldering, especially my very n00b soldering, could do something to the short circuit protection of the MAX4410. Hand soldering is n...
by riden
Mon Mar 01, 2010 11:13 am
Forum: SparkFun Product Questions
Topic: Ultrasonic anemometer
Replies: 15
Views: 17821

Re: Ultrasonic anemometer

Here is another project that's been around for awhile:

http://trekker.customer.netspace.net.au/wind.htm
by riden
Mon Mar 01, 2010 11:06 am
Forum: SparkFun Product Questions
Topic: Need some help with some ideas for senior design!
Replies: 12
Views: 1325

Re: Need some help with some ideas for senior design!

What you need is something called a linear actuator. It is similar to a solenoid, but with the ability to control the distance traveled. Maybe you could leverage (pardon the pun) multiple servos and sometype of gear or pulley system to do the same job. A significant problem to address is quickly mov...
by riden
Sat Feb 27, 2010 5:15 pm
Forum: AVR Microcontrollers
Topic: Sparkfun Relay problem - something wrong?
Replies: 5
Views: 1146

Re: Sparkfun Relay problem - something wrong?

Great! Perhaps the LED is inserted backwards. Have fun with your project.
by riden
Sat Feb 27, 2010 4:16 pm
Forum: AVR Microcontrollers
Topic: Sparkfun Relay problem - something wrong?
Replies: 5
Views: 1146

Re: Sparkfun Relay problem - something wrong?

I looked at the schematic of the relay board and just about any general purpose NPN will work for you.
by riden
Sat Feb 27, 2010 3:38 pm
Forum: AVR Microcontrollers
Topic: Sparkfun Relay problem - something wrong?
Replies: 5
Views: 1146

Re: Sparkfun Relay problem - something wrong?

The transistor that you have on hand is PNP and the circuit requires a NPN. They are completely opposite and need to be driven differently.
by riden
Sat Feb 27, 2010 3:35 pm
Forum: PIC Microcontrollers - Software and Hardware
Topic: 2 Tx and 1or 2 Rx, is this possible on an 18f2550?
Replies: 3
Views: 543

Re: 2 Tx and 1or 2 Rx, is this possible on an 18f2550?

For PICs with a single serial port, you can use the hardware USART for one channel and a software UART for the second. As far as determining the incoming baud rate, the originating device would have to send known characters so the PIC can try different baud rates. For example, it use to be quite com...
by riden
Fri Feb 26, 2010 7:19 pm
Forum: AVR Microcontrollers
Topic: Two Serial Ports
Replies: 6
Views: 1324

Re: Two Serial Ports

Okay, I think I understand now. Can't you continue to use the (hardware, I presume) serial port for the capture and then use a software UART to transmit the data to the printer? You mention "sketches", so are you talking Arduino? If so, have a look at the software UART library.
by riden
Fri Feb 26, 2010 5:47 pm
Forum: AVR Microcontrollers
Topic: Two Serial Ports
Replies: 6
Views: 1324

Re: Two Serial Ports

If you saying that you want two devices to talk with each other and one uses 7-E-1 and the other 8-N-1, that won't directly work. You would have to have software UARTS on both devices so one sends 7-E-1/receives 8-N-1 and the other sends 8-N-1 and receives 7-E-1. Tricky, but it could be done. If you...
by riden
Fri Feb 26, 2010 3:14 pm
Forum: PIC Microcontrollers - Software and Hardware
Topic: Three-legged race: Programming a PIC16F630 with Basic Stamp
Replies: 3
Views: 1018

Re: Three-legged race: Programming a PIC16F630 with Basic Stamp

As Leon said, the PICKit programmers aren't that expensive, but it is great that you were able to get a better understanding of the PIC by building your project. kudos.
by riden
Fri Feb 26, 2010 9:48 am
Forum: USB Development
Topic: UBW ADC problem...EMI\EMC?
Replies: 2
Views: 1257

Re: UBW ADC problem...EMI\EMC?

Your body is forming part a capacitor that is allowing EM interference to be injected into the ADC. You might be surprised at much electromagnetic energy is available. Local radio/TV stations, microwave ovens, motors, even the AC current flowing through the wiring that provides the power to your lig...
by riden
Fri Feb 26, 2010 9:27 am
Forum: SparkFun Product Questions
Topic: Do I need an amplifier?
Replies: 14
Views: 2401

Re: Do I need an amplifier?

Perhaps a stereo headphone chip that delivers 80-150 mw per channel driving 16 or 32 ohm speakers would work if you don't need huge amounts of volume. The chips are pretty cheap and can be powered from 1.8v on up depending upon the chip. National, STMElectronics, and Maxim are three manufacturers th...
by riden
Fri Feb 26, 2010 8:59 am
Forum: PIC Microcontrollers - Software and Hardware
Topic: PIC18f2520 Programmer
Replies: 3
Views: 832

Re: PIC18f2520 Programmer

The 18F2520 and 18F2525 belong to the same family as the datasheets for the devices will indicate. Variations within the family involve features like memory, number of I/O pins, modules (CCP, etc.) One potential problem I see is with the programming circuit you are using. The more recent PICs are mo...
by riden
Fri Feb 26, 2010 8:47 am
Forum: SparkFun Site Questions/Comments
Topic: Forum server and software upgrade
Replies: 27
Views: 3564

Re: Forum server and software upgrade

Same here, both with IE 8 and Firefox 3. Otherwise, thanks for the upgrade!
by riden
Thu Feb 25, 2010 4:40 pm
Forum: SparkFun Product Questions
Topic: 3.5mm Audio Jack -- shorts the inputs when plug is inserted
Replies: 29
Views: 4588

Yes, it slows the discharge of the capacitor until the protection kicks in. You might have to play around with the value. It might be easier to use a diode if your circuit can tolerate the forward voltage drop of the diode.