crasic

Berkeley, CA

Age: 26

I'm a physics student at the University of California.

May
2
comment How to enable Output pin to high by default in Arduino Uno?
Just to add a little, the AVR boots up with all pins defaulting to Tristate, so if you need the high level asserted during reset you should use a pullup, otherwise setting the pins in setup() is the easiest way. If the pin is configured by the bootloader then the solution won't work btw.
Apr
19
awarded Popular Question
Apr
7
comment pcb design: how to route through hole connectors with tightly fitted pins?
This is the only real way to handle higher density breakouts. BGA is ironically very similar. Most fabs can do 6 mil clearance on traces no problem but budget ones may price their services for a larger clearance so important to verify rules
Apr
7
comment What exactly does ARM sell to vendors?
@JDlugosz The processing pipeline for arm is short and the cache and supporting on die peripherals (large contributor to transistor count) are seperate from the core ip (you connect them to the bus). The full SOC/ASIC will have a much larger gate count. A device like an x86 has an additional microcode layer and a much longer (10x) pipeline requiring e.g. more complex branch prediction as well as on die cache and recently on die MMU
Apr
4
comment 24AWG Ribbon Cable Connectors
Without seeing any pictures/PN's I would assume the connector is 0.05" (50Mil) spacing and the Ribbon is 0.1" (100Mil) spacing. As long as the pitch matches it should work, change connector or ribbon cable so they match.
Apr
2
awarded Custodian
Apr
2
reviewed No Action Needed How can I determine voltage and current limit of protoboard?
Apr
2
reviewed No Action Needed Possible to Solder top of through-hole header?
Apr
2
reviewed No Action Needed Reed switch sensitivity
Apr
2
reviewed Approve suggested edit on What is the use of NOT CONNECTED pin in 741 opamp?
Mar
28
awarded Popular Question
Mar
25
awarded Famous Question
Mar
16
comment How to safely connect valve apparatus to a PC?
Neon Bulbs need a high DC voltage for electrostatic field, the output is AC coupled, first you must identify the amplitude of the output then determine the correct solution
Mar
16
comment How do I identify a burnt out component?
This is incorrect, its easy to zap Digital IO pins on an IC or MCU with no obvious external sign that it happened.
Mar
16
comment How do I identify a burnt out component?
1. Identify Malfunction 2. Determine likely culprit (component or circuit region) 3. Measure signals to see what is off 4. Rinse and Repeat
Mar
16
comment Electronics in high temperature - operating 30 mins - 2 hours, up to 500 °F - possible?
Processes that produce transistors that will function at 200C+ junction temperatures are cutting edge, Silicon Carbide mosfets that can handle junction temps of up to 240C are commercially available, as for logic and MCU no chance
Mar
14
comment Why an electrician wiring error could make a PC's USB shield be at 120V when it should be grounded
If your scope ground is tying the live portion of a circuit to PE (incorrect ground clip placement) then with a floating circuit the "grounded" (but not earth) elements would suddenly ly float up to 110V. If the device was earth grounded this would be a ground fault through the scope and trip the earth breaker inside it, but because your device is floating it references the live portion to earth with a misplaced ground clip. This will continue until a conflicting reference is established e.g. usb connection to earth grounded pc or a human body
Mar
14
comment Cadsoft Eagle Version Control
Eagle files are xml files and git works fairly well for version control out of the box. There are a few diff extensions for eagle but they all basically just screenshot various layers and overlay
Mar
14
comment Proper way to wait N cycles in ARM Cortex-M4
Alternatively you wait loop on the clock status register. In case it takes longer to initialize than expected (pll fault or power on brownout/crystal startup)
Mar
11
comment How to calculate the right motor size for a soil sifter
Perhaps an impact design instead of continuous shaking with motor? Or go with a rotating sifter design.
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