Looking for simple way to interface BCD to serial (RS232)
in [Design]
|
From: krw on 5 Jan 2010 18:25 On Tue, 05 Jan 2010 10:42:11 -0600, John Fields <jfields(a)austininstruments.com> wrote: >On Mon, 04 Jan 2010 22:12:14 -0800, "JosephKK"<quiettechblue(a)yahoo.com> >wrote: > >>On Mon, 04 Jan 2010 16:13:56 -0800, Joerg <invalid(a)invalid.invalid> wrote: >> >>>JosephKK wrote: >>>> On Sun, 27 Dec 2009 18:29:16 -0800, Joerg <invalid(a)invalid.invalid> wrote: >>>> >>>>> RFI-EMI-GUY wrote: >>>>>> don wrote: >>>>>>> RFI-EMI-GUY wrote: >>>>>>>> I have a device that has a three digit LED display. The chip that >>>>>>>> drives the LED also has four Binary Weighted outputs (1,2,4,8) and >>>>>>>> three address pins for 100's, 10's and units. I want to drive a FIFO >>>>>>>> UART of some sort to output an RS232 stream so that this device can >>>>>>>> update a software program. Baud rate 300 to 4800 range would be nice >>>>>>>> if possible. >>>>>>>> >>>>>>>> The updates are about 300/second >>>>>>>> >>>>>>>> Is there a real simple hardware FIFO UART that can do this without a >>>>>>>> lot of extra hardware. I don't want a software fix unless I can do it >>>>>>>> in PicAxe and can find code written. >>>>>>>> >>>>>>>> Off the shelf products OK I don't want to reinvent the wheel. >>>>>>>> >>>>>>> Do you docs on the outputs ? >>>>>>> >>>>>>> don >>>>>> >>>>>> I think you are asking the specs of the driving chip? Its an ICM7217IJI >>>>>> Common Cathode 4 LED Display/Programmable Up/Down Counter. The BCD I/O >>>>>> pins and the segment drivers b, d and f (d1, d2, d3) used to select >>>>>> 100's. 10's and units (I may have order reversed). >>>>>> >>>>> That will not be so trivial because this is a chip that drives the LED >>>>> in muxed fashion. >>>> >>>> Which immediatly leads to the next question, what is on the other side of that chip? >>> >>> >>>An analog input signal :-) >> >>And that would lead to an entirely different solution space. > >--- >"Solution space" ??? Certainly. A different problem space, of course, has a different solution space. ;-) >Pretentious nonsense. > >Regardless of what feeds the input(s) of the 7217, the outputs we're >concerned with are the four-bit BCD I/O and the four digit strobes which >identify which BCD digit is which. > >What the OP wants is a way to convert the BCD and digit strobe data into >a format which can be read by an RS-232 DTE box, and several solutions >were presented earlier on in the thread. Your (first) solution was clearly the simplest, given that an appropriate baud rate generator can be had easily.
From: JosephKK on 6 Jan 2010 22:33 On Tue, 05 Jan 2010 10:42:11 -0600, John Fields <jfields(a)austininstruments.com> wrote: >On Mon, 04 Jan 2010 22:12:14 -0800, "JosephKK"<quiettechblue(a)yahoo.com> >wrote: > >>On Mon, 04 Jan 2010 16:13:56 -0800, Joerg <invalid(a)invalid.invalid> wrote: >> >>>JosephKK wrote: >>>> On Sun, 27 Dec 2009 18:29:16 -0800, Joerg <invalid(a)invalid.invalid> wrote: >>>> >>>>> RFI-EMI-GUY wrote: >>>>>> don wrote: >>>>>>> RFI-EMI-GUY wrote: >>>>>>>> I have a device that has a three digit LED display. The chip that >>>>>>>> drives the LED also has four Binary Weighted outputs (1,2,4,8) and >>>>>>>> three address pins for 100's, 10's and units. I want to drive a FIFO >>>>>>>> UART of some sort to output an RS232 stream so that this device can >>>>>>>> update a software program. Baud rate 300 to 4800 range would be nice >>>>>>>> if possible. >>>>>>>> >>>>>>>> The updates are about 300/second >>>>>>>> >>>>>>>> Is there a real simple hardware FIFO UART that can do this without a >>>>>>>> lot of extra hardware. I don't want a software fix unless I can do it >>>>>>>> in PicAxe and can find code written. >>>>>>>> >>>>>>>> Off the shelf products OK I don't want to reinvent the wheel. >>>>>>>> >>>>>>> Do you docs on the outputs ? >>>>>>> >>>>>>> don >>>>>> >>>>>> I think you are asking the specs of the driving chip? Its an ICM7217IJI >>>>>> Common Cathode 4 LED Display/Programmable Up/Down Counter. The BCD I/O >>>>>> pins and the segment drivers b, d and f (d1, d2, d3) used to select >>>>>> 100's. 10's and units (I may have order reversed). >>>>>> >>>>> That will not be so trivial because this is a chip that drives the LED >>>>> in muxed fashion. >>>> >>>> Which immediatly leads to the next question, what is on the other side of that chip? >>> >>> >>>An analog input signal :-) >> >>And that would lead to an entirely different solution space. > >--- >"Solution space" ??? > >Pretentious nonsense. > >Regardless of what feeds the input(s) of the 7217, the outputs we're >concerned with are the four-bit BCD I/O and the four digit strobes which >identify which BCD digit is which. That's odd. I was under the impression that the output of the 7217 was 7 segments of 4 digit LED display scanned. > >What the OP wants is a way to convert the BCD and digit strobe data into >a format which can be read by an RS-232 DTE box, and several solutions >were presented earlier on in the thread. > > >JF
From: RFI-EMI-GUY on 6 Jan 2010 22:42 JosephKK wrote: > On Tue, 05 Jan 2010 10:42:11 -0600, John Fields <jfields(a)austininstruments.com> wrote: > >> On Mon, 04 Jan 2010 22:12:14 -0800, "JosephKK"<quiettechblue(a)yahoo.com> >> wrote: >> >>> On Mon, 04 Jan 2010 16:13:56 -0800, Joerg <invalid(a)invalid.invalid> wrote: >>> >>>> JosephKK wrote: >>>>> On Sun, 27 Dec 2009 18:29:16 -0800, Joerg <invalid(a)invalid.invalid> wrote: >>>>> >>>>>> RFI-EMI-GUY wrote: >>>>>>> don wrote: >>>>>>>> RFI-EMI-GUY wrote: >>>>>>>>> I have a device that has a three digit LED display. The chip that >>>>>>>>> drives the LED also has four Binary Weighted outputs (1,2,4,8) and >>>>>>>>> three address pins for 100's, 10's and units. I want to drive a FIFO >>>>>>>>> UART of some sort to output an RS232 stream so that this device can >>>>>>>>> update a software program. Baud rate 300 to 4800 range would be nice >>>>>>>>> if possible. >>>>>>>>> >>>>>>>>> The updates are about 300/second >>>>>>>>> >>>>>>>>> Is there a real simple hardware FIFO UART that can do this without a >>>>>>>>> lot of extra hardware. I don't want a software fix unless I can do it >>>>>>>>> in PicAxe and can find code written. >>>>>>>>> >>>>>>>>> Off the shelf products OK I don't want to reinvent the wheel. >>>>>>>>> >>>>>>>> Do you docs on the outputs ? >>>>>>>> >>>>>>>> don >>>>>>> I think you are asking the specs of the driving chip? Its an ICM7217IJI >>>>>>> Common Cathode 4 LED Display/Programmable Up/Down Counter. The BCD I/O >>>>>>> pins and the segment drivers b, d and f (d1, d2, d3) used to select >>>>>>> 100's. 10's and units (I may have order reversed). >>>>>>> >>>>>> That will not be so trivial because this is a chip that drives the LED >>>>>> in muxed fashion. >>>>> Which immediatly leads to the next question, what is on the other side of that chip? >>>> >>>> An analog input signal :-) >>> And that would lead to an entirely different solution space. >> --- >> "Solution space" ??? >> >> Pretentious nonsense. >> >> Regardless of what feeds the input(s) of the 7217, the outputs we're >> concerned with are the four-bit BCD I/O and the four digit strobes which >> identify which BCD digit is which. > > That's odd. I was under the impression that the output of the 7217 was > 7 segments of 4 digit LED display scanned. >> What the OP wants is a way to convert the BCD and digit strobe data into >> a format which can be read by an RS-232 DTE box, and several solutions >> were presented earlier on in the thread. >> >> >> JF It actually has both 7 segment drivers and BCD I/O's. The lines used to strobe the display segments also used to address the BCD output. -- Joe Leikhim K4SAT "The RFI-EMI-GUY"� "Use only Genuine Interocitor Parts" Tom Servo ;-P
From: JosephKK on 8 Jan 2010 00:17
On Wed, 06 Jan 2010 22:42:48 -0500, RFI-EMI-GUY <Rhyolite(a)NETTALLY.COM> wrote: >JosephKK wrote: >> On Tue, 05 Jan 2010 10:42:11 -0600, John Fields <jfields(a)austininstruments.com> wrote: >> >>> On Mon, 04 Jan 2010 22:12:14 -0800, "JosephKK"<quiettechblue(a)yahoo.com> >>> wrote: >>> >>>> On Mon, 04 Jan 2010 16:13:56 -0800, Joerg <invalid(a)invalid.invalid> wrote: >>>> >>>>> JosephKK wrote: >>>>>> On Sun, 27 Dec 2009 18:29:16 -0800, Joerg <invalid(a)invalid.invalid> wrote: >>>>>> >>>>>>> RFI-EMI-GUY wrote: >>>>>>>> don wrote: >>>>>>>>> RFI-EMI-GUY wrote: >>>>>>>>>> I have a device that has a three digit LED display. The chip that >>>>>>>>>> drives the LED also has four Binary Weighted outputs (1,2,4,8) and >>>>>>>>>> three address pins for 100's, 10's and units. I want to drive a FIFO >>>>>>>>>> UART of some sort to output an RS232 stream so that this device can >>>>>>>>>> update a software program. Baud rate 300 to 4800 range would be nice >>>>>>>>>> if possible. >>>>>>>>>> >>>>>>>>>> The updates are about 300/second >>>>>>>>>> >>>>>>>>>> Is there a real simple hardware FIFO UART that can do this without a >>>>>>>>>> lot of extra hardware. I don't want a software fix unless I can do it >>>>>>>>>> in PicAxe and can find code written. >>>>>>>>>> >>>>>>>>>> Off the shelf products OK I don't want to reinvent the wheel. >>>>>>>>>> >>>>>>>>> Do you docs on the outputs ? >>>>>>>>> >>>>>>>>> don >>>>>>>> I think you are asking the specs of the driving chip? Its an ICM7217IJI >>>>>>>> Common Cathode 4 LED Display/Programmable Up/Down Counter. The BCD I/O >>>>>>>> pins and the segment drivers b, d and f (d1, d2, d3) used to select >>>>>>>> 100's. 10's and units (I may have order reversed). >>>>>>>> >>>>>>> That will not be so trivial because this is a chip that drives the LED >>>>>>> in muxed fashion. >>>>>> Which immediatly leads to the next question, what is on the other side of that chip? >>>>> >>>>> An analog input signal :-) >>>> And that would lead to an entirely different solution space. >>> --- >>> "Solution space" ??? >>> >>> Pretentious nonsense. >>> >>> Regardless of what feeds the input(s) of the 7217, the outputs we're >>> concerned with are the four-bit BCD I/O and the four digit strobes which >>> identify which BCD digit is which. >> >> That's odd. I was under the impression that the output of the 7217 was >> 7 segments of 4 digit LED display scanned. >>> What the OP wants is a way to convert the BCD and digit strobe data into >>> a format which can be read by an RS-232 DTE box, and several solutions >>> were presented earlier on in the thread. >>> >>> >>> JF > >It actually has both 7 segment drivers and BCD I/O's. The lines used to >strobe the display segments also used to address the BCD output. Looked up most probable chip. Weird. But i more nearly understand now. |