Post by thread:I want an alrernative to BCD code...

Hi to everyone: I got a Microcontroller 8 bit counter and I«m sending the information to an output Port, so, Is there a hardware way to visualize the 8-bit counter in BCD fo rmat (I«m using a display to visualize the digits), like an 8-bit encoder.? I«m new in this and I«d be very glad if someone can help me Thanks

Not to sure of your question! need more info, what type of display? -----Original Message----- From: Ricardo Ponte G <spam_OUTrniniverTakeThisOuTCANTV.NET> To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU <PICLISTKILLspamMITVMA.MIT.EDU> Date: Tuesday, July 07, 1998 12:15 Subject: I want an alrernative to BCD code... Hi to everyone: I got a Microcontroller 8 bit counter and I4m sending the information to an output Port, so, Is there a hardware way to visualize the 8-bit counter in BCD format (I4m using a display to visualize the digits), like an 8-bit encoder.? I4m new in this and I4d be very glad if someone can help me Thanks

Michael, I was using The 74LS47 but this IC only handle 4bits, so I used 2 of thi s, My problem is that when the binary digits go from 9 to 10 I got problems because I don«t get 10 in the dual display: I get some garbage. One soluiton is solve the problem via software but I want to know If via hardware I can solve it. If you know something, plaese let me know. ---------- > De: Michael S. Hagberg <.....mhagbergKILLspam.....I1.NET> > A: EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU > Asunto: Re: I want an alrernative to BCD code... > Fecha: Martes 7 de Julio de 1998 04:14 AM > > look at a bcd display driver. 7447 or 74LS47 to drive a display. > > before other chime in, yes there are displays with bcd built in, but are not > easy to find and are much more expensive. > > michael > > > >{Original Message removed}

On Mon, 6 Jul 1998, Ricardo Ponte G wrote: > Hi to everyone: > > I got a Microcontroller 8 bit counter and I4m sending the information to > an output Port, so, > > Is there a hardware way to visualize the 8-bit counter in BCD format > (I4m using a display to visualize the digits), like an 8-bit encoder.? > > > I4m new in this and I4d be very glad if someone can help me > > Thanks The usual way to do it, is an EPROM (from the junk box for one off), and a counter to cycle through the 3 muxed display positions required, (or (a) PALs). The PIC way to do it, is a PIC with at least 18 IO pins that runs a multiplexed LED display. The latter variant also gives the opportunity to set up serial transmission in ASCII (RS232) of the read out value in a neat packet ;) Comes in very handy when adding some smarter contol later ;) The mean solution (which is what I'd prefer) is a PIC54 and a CMOS 4021 used to read the 8 bits. The pic reads the 8 bits through the 4021, drives a muxed display AND sends serial data packets on change. Neat, eh ? ;) There's even room for a button to enable display if battery-driven, and ample space for auto-off. hope this helps, Peter PS: I've heard that standard CMOS parts are being phased out. I wonder WHY ?!

> From: Ricardo Ponte G <rniniverspam_OUTCANTV.NET> > I was using The 74LS47 but this IC only handle 4bits, so I used 2 of this, > My problem is that when the binary digits go from 9 to 10 I got problems > because I don´t get 10 in the dual display: I get some garbage. One > soluiton is solve the problem via software but I want to know If via > hardware I can solve it. I think what you need is an 8 bit BCD up/down counter in software. I posted this routine two months ago: BCD_INCR: MOVLW 67 ADDWF CNT,F MOVLW -60 SKPDC MOVLW -66 SKPC ADDWF CNT,F RETURN BCD_DECR: MOVLW 0xFF ADDWF CNT,F MOVLW -6 SKPC MOVLW -66 SKPDC ADDWF CNT,F RETURN A binary to BCD converter can also help. Reggie