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« Reply #30 on: January 10, 2012, 12:56:46 am » |
I didn't know what the PPM's needed to be or anything I can read the ones I did from print-to-PDF, not sure why you can't? Let me to a screen rotation and I'll grab some hi-res ones.
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« Last Edit: January 10, 2012, 01:17:05 am by magnethead794 »
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« Reply #33 on: January 10, 2012, 05:50:09 am » |
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?
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« Reply #34 on: January 10, 2012, 06:41:36 am » |
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.
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« Reply #35 on: January 10, 2012, 07:02:38 am » |
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.
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« Reply #36 on: January 10, 2012, 12:36:50 pm » |
Made my first layout all on my own. I measured out the board and LED spacing myself so I know it's all good  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%3dhttp://i1105.photobucket.com/albums/h355/magnethead494/dial_board_dig1-1.jpgReason 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.
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« Last Edit: January 10, 2012, 12:49:59 pm by magnethead794 »
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« Reply #37 on: January 10, 2012, 12:42:26 pm » |
So thats 2 sets of 5 LEDs in series with a resistor? Both turn on at the same time?
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« Reply #38 on: January 10, 2012, 12:50:35 pm » |
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. http://i1105.photobucket.com/albums/h355/magnethead494/dial_board_dig1-1.jpg
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« Last Edit: January 10, 2012, 01:07:31 pm by magnethead794 »
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« Reply #39 on: January 10, 2012, 01:33:20 pm » |
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« Reply #40 on: January 10, 2012, 05:17:56 pm » |
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.
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« Reply #41 on: January 10, 2012, 05:42:27 pm » |
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.
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« Reply #42 on: January 10, 2012, 05:49:36 pm » |
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.
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« Reply #44 on: January 11, 2012, 12:05:09 am » |
Are you putting down discrete pads vs chip symbols? Makes it hard to follow what you are doing.
Pic's are coming thru nice.
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