Search found 380 matches

by macegr
Thu Dec 29, 2011 1:17 pm
Forum: PCB Design Questions
Topic: My rant about Eagle
Replies: 13
Views: 2443

Re: My rant about Eagle

Well, yeah, but innate ability may have accounted for a lot of that, too :) Give yourself some credit too
by macegr
Mon Dec 26, 2011 8:33 pm
Forum: PCB Design Questions
Topic: Eagle Question
Replies: 12
Views: 4634

Re: Eagle Question

never liked the idea of hidden power pins, wonder who does? Power pins are omitted while designing many op-amp schematics. It's less clutter to worry about while concentrating on other aspects of the circuit. However, I am usually drawing a schematic in Eagle with an eye to eventual PCB layout. I d...
by macegr
Mon Dec 26, 2011 2:06 am
Forum: PCB Design Questions
Topic: My rant about Eagle
Replies: 13
Views: 2443

Re: My rant about Eagle

^^^ THIS 100 times. If you buy an expensive CAD package expecting it to do everything for you with a seamless integration between thought and action, you will be sorely disappointed. And, you'll still have to use that expensive CAD package, since you already bought it. This is at least part of the r...
by macegr
Tue Dec 20, 2011 12:21 pm
Forum: SparkFun Product Questions
Topic: Chloroform detection
Replies: 3
Views: 610

Re: Chloroform detection

Ah that's perfect, I've been doing the ol' sniff test but the next time someone asks me "does this rag smell like chloroform" I can pull out that sensor.

Let's google "artificial kidneys and liver" next...
by macegr
Fri Dec 02, 2011 4:13 pm
Forum: PCB Design Questions
Topic: Which pcb design software for weird outlines?
Replies: 3
Views: 1350

Re: Which pcb design software for weird outlines?

I've never had problems making precise outlines with Eagle. In fact, I've used Eagle as vector CAD for non-electronic purpose, on occasion. The interface is not very different from AutoCAD...you can type in numbers to get very accurate line placement. Do you have an example of the type of board outl...
by macegr
Tue Nov 29, 2011 7:28 pm
Forum: SparkFun Product Questions
Topic: EMI issues with USB-RS-485 converter
Replies: 20
Views: 2734

Re: EMI issues with USB-RS-485 converter

When you have the hardware problem sorted out...it's always good to manage serial communications with an eye to signal corruption. Either use a checksum to throw away bad packets if losing a few isn't an issue, or set up a bidirectional system with retries. Non-blocking communication and packet-comp...
by macegr
Thu Oct 13, 2011 8:06 pm
Forum: Arduino
Topic: Arduino + shift register
Replies: 6
Views: 2864

Re: Arduino + shift register

the output bits can toggle at the shift-clock rates while shifting bits down their positions. You probably don't realize that the 74HC595 has a shift register AND a storage register. The output bits aren't going to change during shifting. They'll all change when the storage register clock is pulsed.
by macegr
Thu Oct 13, 2011 12:56 am
Forum: Arduino
Topic: Arduino + shift register
Replies: 6
Views: 2864

Re: Arduino + shift register

suggestion.. connect the shift register's output enable to a microprocessor I/O bit. Disable the outputs while shifting. This will avoid big current spikes. Not following you on this one...how? Seems like it would actually create a huge current spike by turning off and then on every active LED, com...
by macegr
Wed Oct 12, 2011 3:22 pm
Forum: PCB Design Questions
Topic: Subtracting soldermask from silkscreen in Gerber files
Replies: 6
Views: 1790

Re: Subtracting soldermask from silkscreen in Gerber files

Subtracting the soldermask from the silkscreen layer is a good final level of stupidity-proofing the manufacturing process anyway. I haven't used a PCB manufacturer that didn't do it, and won't in the future. It's easier for them to do it as part of the manufacturing process than it is for you to cr...
by macegr
Thu Oct 06, 2011 3:29 pm
Forum: PCB Design Questions
Topic: Link Ground Plane to Drills
Replies: 4
Views: 898

Re: Link Ground Plane to Drills

Vias are not covered with soldermask by default in Eagle at least. You would need to go into DRC and set a minimum size below which the via is automatically tented. The other advantage of vias for this, again in Eagle, is that you don't need to add the pad as a part in the schematic. The via is simp...
by macegr
Thu Oct 06, 2011 12:27 am
Forum: PCB Design Questions
Topic: Link Ground Plane to Drills
Replies: 4
Views: 898

Re: Link Ground Plane to Drills

Yes, if you care about passing a signal through the board, a via is definitely the correct choice.
by macegr
Mon Oct 03, 2011 11:49 am
Forum: SparkFun Product Questions
Topic: Tx Rx pins
Replies: 7
Views: 661

Re: Tx Rx pins

Sometimes people new to the field don't even know how basic their question is, or when they're being lazy :)

Now I'll agree, that explanation is at odds with being able to design and build a touchscreen shield.
by macegr
Sun Oct 02, 2011 11:03 pm
Forum: SparkFun Product Questions
Topic: Tx Rx pins
Replies: 7
Views: 661

Re: Tx Rx pins

Might be coming down a little hard on this guy, Mee_n_Mac. They may not know that TX and RX pins are hardly a universal concept, what a UART is, how to read a datasheet, or even what a datasheet is supposed to contain.
by macegr
Tue Sep 27, 2011 11:20 pm
Forum: SparkFun Product Questions
Topic: "wearable electronics" - Lit costume wig
Replies: 8
Views: 1277

Re: "wearable electronics" - Lit costume wig

Those are tiny fiber bundles attached to a Christmas light strand...
by macegr
Tue Sep 27, 2011 2:50 am
Forum: SparkFun Product Questions
Topic: "wearable electronics" - Lit costume wig
Replies: 8
Views: 1277

Re: "wearable electronics" - Lit costume wig

Don't count out the fiber optic hair extensions just yet. While the existing form factor and mode of operation might not be exactly what you need, they're still a good source of fiber optic bundles in approximately the correct length and flexibility. Otherwise, you can expect to pay a LOT for bare f...