Search found 1461 matches

by YahooArchive
Thu Feb 14, 2013 5:25 am
Forum: Other Hardware interfaces
Topic: measuring voltages greater than 3.3V
Replies: 6
Views: 10996

measuring voltages greater than 3.3V

I could swear I saw a sample project to do this somewhere... I have a power source that will always read between 11 - 14, or 0 volts. (It's the output of a charge controller for a solar powered WiFi tower.) I'd like to periodically read the output voltage, and send it to my desktop computer. I alrea...
by YahooArchive
Thu Feb 14, 2013 5:24 am
Forum: Other Hardware interfaces
Topic: LED drive
Replies: 8
Views: 11067

Re: LED drive

I don't know this chip / stamp / module but I looked at the specs for LPC111x More specificly I looked at the specs for a "High-drive output pin PIO0_7" and it shows - The pin can sorce a MIN of 12 mA at Vdd > 2.5v HOWEVER it can only sink about 4 mA at the same Vdd (So you killed it lol) This means...
by YahooArchive
Thu Feb 14, 2013 5:23 am
Forum: Other Hardware interfaces
Topic: LED drive
Replies: 8
Views: 11067

Re: LED drive

Thanks, Darin, Bruce.

I think I can safely conclude I need a replacement chip :-)
by YahooArchive
Thu Feb 14, 2013 5:22 am
Forum: Other Hardware interfaces
Topic: LED drive
Replies: 8
Views: 11067

Re: LED drive

I have a couple of testers I built 2 years ago using an ULN2803 to drive 24
VDC ice cube relays with these boards and they have run 5 days a week since
without a problem.
by YahooArchive
Thu Feb 14, 2013 5:22 am
Forum: Other Hardware interfaces
Topic: LED drive
Replies: 8
Views: 11067

Re: LED drive

I'm pretty sure that pin is toast. Need to drive loads like that using a transistor. Use something like a BC547 with the pin hooked to the base of the transistor. You may want to put a 10k resistor between the pin and the base of the transistor, even just the base will pull more current per pin then...
by YahooArchive
Thu Feb 14, 2013 5:21 am
Forum: Other Hardware interfaces
Topic: LED drive
Replies: 8
Views: 11067

Re: LED drive

I would say 100 ohms is too small of a resistor for use on a red or green standard LED. That would be equivalent to 20 mA from an output. IO(7) is rated at 20 mA drive, but the rest are 4 mA drivers. I've been using 330 or 470 ohm resistors. There is also a maximum GND or supply current of 100 mA, s...
by YahooArchive
Thu Feb 14, 2013 5:21 am
Forum: Other Hardware interfaces
Topic: LED drive
Replies: 8
Views: 11067

Re: LED drive

Hi All I have been using the BASICBoard from Coridiumcorp for some time and have managed at some point to drive LEDs from P0 using code like the following: --- while(1) IO(1) = x and 1 wait(250) IO(2) = x and 1 wait(250) loop ---- At some point I stopped being able to drive pins P0(2) to P0(10) high...
by YahooArchive
Thu Feb 14, 2013 5:19 am
Forum: Kitchen sink
Topic: RobotBASIC
Replies: 0
Views: 4989

RobotBASIC

FYI, the December issue of Servo Magazine has an article I wrote called Power
Beyond the Shield. It shows how the RobotBASIC Robot Operating System On a Chip
can be used with Arduino and other processors.
John
by YahooArchive
Thu Feb 14, 2013 5:17 am
Forum: Software issues
Topic: RSIR and reset
Replies: 2
Views: 4145

Re: RSIR and reset

thanks Bruce, it didn't even cross my mind to check for that -- jc
by YahooArchive
Thu Feb 14, 2013 5:17 am
Forum: Software issues
Topic: RSIR and reset
Replies: 2
Views: 4145

Re: RSIR and reset

On the ARMmite, PRO, PROplus and SuperPRO there is a resistor to 3.3V and cap to
GND that pulls reset low setting EXTR

Kind of an old habit, adding this circuit to micros, though the internal POR
circuits now work quite well