not understanding 7 segment multiplexing

magnethead794:
I'm not sure what part number for the oscillator..mouser only has one xtal and they want $15 for it.

Unless you want better than 0.5% clock accuracy, you can use one of these http://uk.mouser.com/Passive-Components/Frequency-Control-Timing-Devices/Resonators/_/N-6zu9h?P=1z0wnukZ1z0z5h6&Keyword=ceramic+resonator&FS=Tru. If you use one of the 3-terminals ones, you can omit the 22pf capacitors.

If you want a crystal, Mouser seems to have those too: http://uk.mouser.com/Passive-Components/Frequency-Control-Timing-Devices/Crystals/_/N-6zu9f?P=1z0wnukZ1z0z7l5.

dc42:

magnethead794:
I'm not sure what part number for the oscillator..mouser only has one xtal and they want $15 for it.

Unless you want better than 0.5% clock accuracy, you can use one of these http://uk.mouser.com/Passive-Components/Frequency-Control-Timing-Devices/Resonators/_/N-6zu9h?P=1z0wnukZ1z0z5h6&Keyword=ceramic+resonator&FS=Tru. If you use one of the 3-terminals ones, you can omit the 22pf capacitors.

If you want a crystal, Mouser seems to have those too: http://uk.mouser.com/Passive-Components/Frequency-Control-Timing-Devices/Crystals/_/N-6zu9f?P=1z0wnukZ1z0z7l5.

I'm using a time function, but it's relative, not absolute. So the millis() doesn't have to be absolutely perfect as long as it'll still run on the bootloader.

What's the difference between crystal and resonator?

magnethead794:
What's the difference between crystal and resonator?

Ceramic resonators generally have a quoted frequency accuracy of 0.5% over their temperature range. Crystals are more typically 0.05% or 0.03%. Anything up to 2% is OK for serial comms, including bootloading. The Arduino Uno uses a resonator.

dc42:

magnethead794:
What's the difference between crystal and resonator?

Ceramic resonators generally have a quoted frequency accuracy of 0.5% over their temperature range. Crystals are more typically 0.05% or 0.03%. Anything up to 2% is OK for serial comms, including bootloading. The Arduino Uno uses a resonator.

Thanks. I've sent KirAsh4 about 5 emails tonight as I try to learn eagle, so I'm going to let her catch up. She builds her own arduinos like CrossRoads does, so i don't know if she uses resonators or crystals.

Made my first layout all on my own.

I measured out the board and LED spacing myself so I know it's all good :slight_smile: LED's are on .1 lead spacing with 6.5mm vertical separation at a 10 degree angle. Board is 1.19" x 3.38" and matches the main digit board. Solder pads are on 0.1" spacing, only concern is if they're too close and wether or not they're through-hole?

Honestly I feel accomplished...it looks something close to right! Not bad for ~4 hours of work!

spec'd with this resistor. 5x 3.3V LED's running off 18 volts @ 15mA. http://www.mouser.com/ProductDetail/Vishay/TNPW0603100RDEEA/?qs=sGAEpiMZZMvdGkrng054txRufvdcoZTXnzdCIj30MTQ%3D

Reason for doing the leading 1 separate from the other 3 digits is because it's cheaper than buying an entire full digit. 3 single digits are $8.95, and the 1 will cost $3 to make and save me 2 inches of length, vs a 10 inch long 4 digit for $33. Also saves me a $5.67 selector BCD switch, a shift register, and a slave board's worth of SMD soldering. I'd make the whole panel, but the cost would skyrocket out of control far too quickly.

So thats 2 sets of 5 LEDs in series with a resistor? Both turn on at the same time?

CrossRoads:
So thats 2 sets of 5 LEDs in series with a resistor? Both turn on at the same time?

Yes. Idential to the rest of the boards segment-wiring wise, I just joined both segments to common power. Sole purpose is to display a 1, and only a 1.

The single digit boards are 2.5" wide. So I'll have 8.2" total and 3.375" tall. I got the one down to 0.97 of an inch wide.

So to bring the parts list up to page,

Arduino packaging (for the 4 main boards):

10K resistor pull-up for reset: Vishay TNPW060310K0DEEA: http://www.mouser.com/ProductDetail/Vishay/TNPW060310K0DEEA/?qs=sGAEpiMZZMvdGkrng054t2aw0xAnHr8cyglfeXQbQ5Q%3D
Atmel 328P-AU: http://www.mouser.com/ProductDetail/Atmel/ATMEGA328P-AU/?qs=sGAEpiMZZMtVoztFdqDXO3RbBx7FKCmV
Oscillator: http://www.mouser.com/ProductDetail/ABRACON/ABL-16000MHZ-B2/?qs=sGAEpiMZZMsBj6bBr9Q9aUe%252bp9Tek3UMf7HCqm%252bSvX0%3D
Capacitors for oscillator: http://www.mouser.com/ProductDetail/Vishay-Vitramon/VJ0402A180GXXCW1BC/?qs=sGAEpiMZZMvQvaS66kI3To5vmFxkrtf%2Fj9ftZUdMLTU%3D
3 pin IDC connector for connecting to indicator board: http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/CHG-1003-001010-KEP/?qs=sGAEpiMZZMtsLRyDR9nM18SX895SbBDG7PcRT8JksiU%3D


Selector Board:

Switch: NKK Binary Coded Decimal FR01AR10PB-W-S NKK Switches | Mouser Europe
Knob for Switch: NKK AT433A: AT433A NKK Switches | Mouser Europe
RJ45 port, right angle: FCI 54602-908LF: http://www.mouser.com/ProductDetail/FCI/54602-908LF/?qs=sGAEpiMZZMvQhAhQbXdbBseXx%252btLS%252bLV8lpIitz%2FSwI%3D
RJ45 port, vertical: Molex 95503-2881: http://www.mouser.com/ProductDetail/Molex/95503-2881/?qs=sGAEpiMZZMvQhAhQbXdbBpAwtzh57ZJU%252b12Gp50sFk4%3D
3 pin IDC connector for connecting to selector board: http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/CHG-1003-001010-KEP/?qs=sGAEpiMZZMtsLRyDR9nM18SX895SbBDG7PcRT8JksiU%3D
3 conductor cable for connecting to indicator board: http://www.mouser.com/ProductDetail/Alpha-Wire/1173C-SL005/?qs=sGAEpiMZZMuPnr6I6Psi5cXCNOyBX32jeaPsJSM2Yeg%3D


Indicator Board:

Indicator Display: Lite-On LTC-4727JR: http://www.mouser.com/ProductDetail/Lite-On/LTC-4727JR/?qs=sGAEpiMZZMvkC18yXH9iIgvlR62MGniBcMrTIHXqM2o%3D
330 ohm SMD resistor for indicator: Vishay/Dale CRCW0603330RJNTA: http://www.mouser.com/ProductDetail/Vishay-Dale/CRCW0603330RJNTA/?qs=sGAEpiMZZMtlubZbdhIBILxXaVI2KEnFAwsUpwT18g4%3D
3 pin IDC connector for connecting to selector board: http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/CHG-1003-001010-KEP/?qs=sGAEpiMZZMtsLRyDR9nM18SX895SbBDG7PcRT8JksiU%3D
3 conductor cable for connecting selector board: http://www.mouser.com/ProductDetail/Alpha-Wire/1173C-SL005/?qs=sGAEpiMZZMuPnr6I6Psi5cXCNOyBX32jeaPsJSM2Yeg%3D


Master Display Board:

Bit Shifter: TI TPIC6B595: http://www.mouser.com/ProductDetail/Texas-Instruments/TPIC6B595DWRG4/?qs=sGAEpiMZZMtsbn1GaJysl5n9mZ%252buky8fvzWTfbYIY%252bQ%3D
5 volt regulator: STMicro LD29150DT50R: http://www.mouser.com/ProductDetail/STMicroelectronics/LD29150DT50R/?qs=sGAEpiMZZMsGz1a6aV8DcF1%2FpLH4TRMJcGtMnQnSZII%3D
RJ45 port, right angle: FCI 54602-908LF: http://www.mouser.com/ProductDetail/FCI/54602-908LF/?qs=sGAEpiMZZMvQhAhQbXdbBseXx%252btLS%252bLV8lpIitz%2FSwI%3D
+12 (+18) volt power-in terminal block: Molex 38720-7202: http://www.mouser.com/Search/ProductDetail.aspx?R=38720-7202virtualkey53810000virtualkey538-38720-7202
3 pin IDC connector for connecting master/slave boards: http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/CHG-1003-001010-KEP/?qs=sGAEpiMZZMtsLRyDR9nM18SX895SbBDG7PcRT8JksiU%3D
3 conductor cable for connecting master/slave boards: http://www.mouser.com/ProductDetail/Alpha-Wire/1173C-SL005/?qs=sGAEpiMZZMuPnr6I6Psi5cXCNOyBX32jeaPsJSM2Yeg%3D

(3 conductor is to keep +12/+5/gnd away from mosi/ss/sclk)


Slave Board:

Bit Shifter: TI TPIC6B595: http://www.mouser.com/ProductDetail/Texas-Instruments/TPIC6B595DWRG4/?qs=sGAEpiMZZMtsbn1GaJysl5n9mZ%252buky8fvzWTfbYIY%252bQ%3D
3 pin IDC connector for connecting master/slave boards: http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/CHG-1003-001010-KEP/?qs=sGAEpiMZZMtsLRyDR9nM18SX895SbBDG7PcRT8JksiU%3D
3 conductor cable for connecting master/slave boards: http://www.mouser.com/ProductDetail/Alpha-Wire/1173C-SL005/?qs=sGAEpiMZZMuPnr6I6Psi5cXCNOyBX32jeaPsJSM2Yeg%3D

(3 conductor is to keep +12/+5/gnd away from mosi/ss/sclk)


"One" Board-

10x LED's http://www.mouser.com/ProductDetail/VCC/VAOL-5GAE4/?qs=io7aH2hdVh64NnNrLmZ6Dw%3D%3D
for 3.3V LED's, 100 ohm resistor (18V w/ step-up), 0603 pkg http://www.mouser.com/Search/ProductDetail.aspx?R=TNPW0603100RDEEAvirtualkey61300000virtualkey71-TNPW0603100RDEEA
for 2V LED's, 220 ohm resistor (12 volt supply/no step-up) http://www.mouser.com/ProductDetail/Vishay/TNPW0603221RBEEA/?qs=sGAEpiMZZMu61qfTUdNhGxJRuluY1gSVpCEZEZkSFzg%3D
Slave Display Board:

So it's been determined that since I'll be using serial.available and not using any critical time related functions, I can forego the crystal completely and rely on the internal 1MHz clock.

magnethead794:
So it's been determined that since I'll be using serial.available and not using any critical time related functions, I can forego the crystal completely and rely on the internal 1MHz clock.

Not unless you calibrate the internal clock, otherwise it is likely that your serial comms won't work. Unless you have a frequency meter, it's easier to use a crystal or resonator than calibrate the internal clock. Whether or not you use serial.available has nothing to do with it.

dc42:

magnethead794:
So it's been determined that since I'll be using serial.available and not using any critical time related functions, I can forego the crystal completely and rely on the internal 1MHz clock.

Not unless you calibrate the internal clock, otherwise it is likely that your serial comms won't work. Unless you have a frequency meter, it's easier to use a crystal or resonator than calibrate the internal clock. Whether or not you use serial.available has nothing to do with it.

KirAsh4 said he doesn't use an external clock if he doesn't have to. didn't specify on setting the internal clock, though.

here's where I'm at right now. Disclaimer: as a beginner, i don't want to run traces between solder pads. Yes it dirties things up, but I'd rather than than melting a trace.

Still have to do indicator, master, and selector.

Are you putting down discrete pads vs chip symbols? Makes it hard to follow what you are doing.

Pic's are coming thru nice.

CrossRoads:
Are you putting down discrete pads vs chip symbols? Makes it hard to follow what you are doing.

Pic's are coming thru nice.

not sure exactly what you mean?

and I'm printing to A0 paper PDF as ~4x scale or so then converting to jpg.

Here's what I mean.
I layed out 10 LEDs, 2 resistors, a connector.
The board layout looks like it.
Yours just looks like a bunch of holes that are connected, can't tell what it is.

CrossRoads:
Here's what I mean.
I layed out 10 LEDs, 2 resistors, a connector.
The board layout looks like it.
Yours just looks like a bunch of holes that are connected, can't tell what it is.

I'm a beginner so you have to bear with me learning my way through eagle.

so if I go per http://arduino.cc/en/Tutorial/ArduinoToBreadboard minimalist approach and don't use a resonator/crystal, it will function at 1 MHz, right?

so 9600bps serial in code will actually be 9600/16 = 600bps?

If board space gets tight, I may need that extra little bit of space in leu of resonator. Didn't realize how hard it was going to be to fit all this stuff on a 2" square board. I'm gonna see how far I can get.

I am not sure, I have not operated at other than 16 MHz in my designs.

I tallied it up. I can buy SF's small indicator cheaper than I can build it, when you calculate time. Maybe they'll have a new revision with mounting holes, if not, I came up with a mounting method. I thought about it, and having a 10K resistor on the VCC line shold somewhat make up for not having on on each digit supply.

Here's where KirAsh and I landed. Only have to make 2 boards. Use the sparkfun board for indication, and use the selector board to run the Tx to the indicator and SPI to the shift registers. On the shift boards, the first one gets +12/+5/gnd through a 3 position terminal block, SPI over the Cat5, then it all gets passed on from pin headers.