....It just takes a small trick... Nice! There are some smart people on this list... :) On 1/14/17, Harold Hallikainen wrote: > I used to use the Allegro 5832 pull-down driver. It had a 32 bit shift > register, latch, and high current drivers. It's long discontinued, though= .. > Also, it was pull down only. Allegro has no replacement. Also, they were > pull down only, so they would not work with your two color LEDs (though > you could use two outputs with a pull-up resistor on each end). > > Good luck! > > Harold > >> On Sun, Jan 15, 2017 at 07:17:05AM +1000, David Duffy (AVD) wrote: >>> I'm not aware of any PICs that can swing their outputs more than 5V. >>> David... >> >> David, >> >> There's no need for more than a 5V swing as long as you are using 2 pin >> bi-color LEDs and the forward voltage of both isn't more than 2.5 volts. >> >> It just takes a small trick. What you do is tie one end of the LED to a >> 2.5V rail and the other end to a PIC I/O pin. You can get all three >> states >> from a single pin: >> >> 0V output turns on one color LED >> 5V output turns on the other color LED >> input turns the LED off. >> >> If you have a lot of LEDs, you can create a 2.5V rail using a power >> supply. >> For a few LEDs a stiff voltage divider will do. >> >> BAJ >> >>> >>> On 14/01/2017 2:16 PM, Anthony Nixon wrote: >>> > A surface mount PIC cannot do the job ?? >>> > >>> > cheers >>> > >>> > Tony >>> > >>> > On Sat, Jan 14, 2017 at 9:26 AM, David Duffy (AVD) >>> > wrote: >>> >> I have an idea for a project that needs to drive 8 outputs for >>> (remotely >>> >> mounted) 2-pin bi-colour LEDs. >>> >> >>> >> Since the LEDs are 2-pin, I'll need to reverse the polarity on them >>> >> individually. There may be 1 or 2 LEDs on each output, so if they >>> were >>> >> in series that means I need a swing of more than 5V. >>> >> >>> >> I was thinking of two shift registers arranged as 8 H-bridges, but >>> can't >>> >> seem to find any that have a Vdd of more than 5V and have an output >>> >> current of more than a couple of mA. >>> >> >>> >> There are H-bridges out there, but the cost and space adds up pretty >>> >> quickly for 8 outputs. Ideally I'd like nothing finer pitch than a >>> SOIC >>> >> package. >>> >> >>> >> Any ideas? >>> >> >>> >>> >>> -- >>> ___________________________________________ >>> David Duffy Audio Visual Devices P/L >>> Unit 8, 10 Hook St, Capalaba 4157 Australia >>> Ph: +61 7 38235717 Fax: +61 7 38234717 >>> Our Web Site: www.audiovisualdevices.com.au >>> ___________________________________________ >>> >>> -- >>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >> >> -- >> Byron A. Jeff >> Associate Professor: Department of Computer Science and Information >> Technology >> College of Information and Mathematical Sciences >> Clayton State University >> http://faculty.clayton.edu/bjeff >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > > -- > FCC Rules Updated Daily at http://www.hallikainen.com > Not sent from an iPhone. > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .