7 specific volatges to to 1,n,2,3,4,5,6 numbers in Alpha-numeric Display

On 5 Feb 2006 10:39:30 -0800, snipped-for-privacy@persona.ca put finger to keyboard and composed:

Use the comparator outputs to drive a 74LS148 8-line-to-3-line priority encoder (or something similar), and then follow this with a BCD-to-7 segment decoder/driver. I'd use an additional comparator to detect neutral, and then apply this signal to the enable input of the

74148 so that the display is blanked.

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.

How about using a LM3914 in dot mode with each output driving the required pins of the LED display via diodes?

Anyone with a good idea feel free to post schematic, as it will help me make sense of all this.

I'd consider using different resistors to get a more even spread.

run that output into a priority encoder chip and then the output from that into a BCD to 7-segment chip. neutral will need to be a special case.done with a bunch of gates...

It's that or use a microcontroller, it depends on how much space you have and wether you prefer to program with a soldering iron or a keyboard. a microcontroller with a DAC in it would obsolete your lm339 comparators...

Is this is for a motorbike?

A/N = alphanumeric? is 7-segment enough? _ _ _ | _| _| |_| |_ _ | |_ _| | _| | | (view with a fixed pitch font like courier)

Bye. Jasen

yes it is for a motorbike, GSXR actually.

Love that line about the program with soldering iron. I have no fear in programming with a computer, I actually do this for a living(computers) but not electronics.

I just need to know what chips to use for my soldering iron Basc language. And seven segment is enough as an "n" can be made.

yes it is for a motorbike, GSXR actually.

** LED displays are rendered in invisible in average daylight.

....... Phil

Since you have digital outputs from your comparators, if you don't want to send them to a PIC and do some code-crunching, send these to an EPROM as the address lines and use the outputs to drive the seven-segment display. Program the EPROM to suit.

Cheers.

Ken

On 5 Feb 2006 15:23:44 -0800, snipped-for-privacy@persona.ca put finger to keyboard and composed:

You could probably do everything with a single PICAXE-18X chip:

The PICAXE has a built-in ADC and an on-chip BASIC interpreter. No comparators would be needed, only the LED digit, and driver transistors for each segment. The chip can be programmed via a PC serial port.

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.

you'd need an extra level of buffering. AIUI the 3914 has current-limited outputs which would make the "6" dimmer than the "1"

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Bye.
   Jasen

True.

LOL, yeah, tell that to the traffic light designers and message board manufacturers. I suppose the auto manufacturers are wrong too, as are the manufacturers of truck indicator and stop lights.

"The Real Andy"

= Andrew Pearson:

Andy is a despicable, chronic alcoholic, anencephalic, autistic moron from Brisbane.

Then there are his bad points.

BTW

Anyone can try a typical 7 segment LED display in bright daylight and see the outcome.

........ Phil

The line's not mine unforunately I encountered it in one of the

*.electronics* newsgroups last week.

ISTR someone has already offered a list including part numbers. I don't see the priority encoder chip in the Jaycar catalogue (paper) but someone offered a part number and I expect they can nominate a source for the part too.

getting the 'n' will probably need to be done separately from the rest of the task.

for the 'n' three small diodes (1N914),a 1k resistor and a cheap transistor should be sufficient, (in addition to your existing setup , the 7-seg display and its resistors)

If you want to go the microcontroller route this is an ideal first project (no interrupts, just a simple loop reading the dac and comparing the input with a list of numbers, looking up another list of bit-patterns and sending out the output)

being an Atmel user myself I'd say use a ATtiny26 microcontroller ($8nz) (Jaycar doesn't list that part, but an industrial place near me has it

7 resistors (to limit the LED current) and a common anode 7 segment display, a resonator to clock it, and a pin header for the programer, power supply, connectors for your other harware etc...

The chip will run off 2.7-6V so your exisiting 5V would work.

for a programmer the silicon chip kit looks good, but there are cheaper parallel port progrmmers that work well too,

This looks like the official atmel in-circuit programmer circuit, which I have used, and had no problems with: 1 74HC244 chip (mine has the markings sanded off) and 3 passives ) and theres plenty of free software out there.

The chip has an internal clock that could be used instead of the resonator but it takes a more complex programmer to activate the clock.

The chip has flash memory for the program so your $8 gets you potentially 1000 tries to get your software right. There's free C and Asssmber tools. there'a a BASIC too, dunno if it's free (it's for windows which I dislike, and I prefer C to BASIC anyway), but it seems to pop up on P2P searches.... If you decide to use a PIC instead I'd reccomend you get or build a decent programmer those serial-port powered ones are kind of flaky, but the ones that are powered externally work well.

Bye. Jasen

YAWN....

Quote from Phil "** LED displays are rendered in invisible in average daylight."

Here is something that might set you going in the right direction if you decide to use a pic.

this particular widget is a flying spot VU meter using 12 LEDs across 4 port pins of an 8 pin pic and the onboard a to d converter, but by rejigging the breakpoints to your voltages (V/5*256) and using different bit patterns on 7 output lines of a 14 pin pic the job would be done. Oh yes you can get plenty bright enough 7 seg displays to be daylight readable...or you could go retro and use a numitron (but you would need something like a ULN2003 as the little pic doesn't have enough output grunt). M