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October 16, 2008
Product COM-00314 |
Technically, yes - IF you put it it a circuit designed for such a purpose. This component by itself will not do the job, but it will isolate one circuit from another with each side potentially operating at different Vcc values. I would recommend using a diode and capacitor on the AC side to rectify things to a somewhat choppy DC voltage which could then be fed to the LED side of this part. You would still need an independent 5v supply on the transistor side to detect changes in the AC input (actually, that’s exactly how I’m currently thinking of using this part).
Product TOL-11456 |
about 2 weeks ago
I haven’t put these on a scope, but I am using one of them to run a bluetooth audio gateway. I bought a BlueGate product off of Amazon that was powered by a lithium polymer battery. The charging circuit died after owning it about a month and, to be honest, the battery feature was a pain in the butt. When you plugged in the charger, it would not function as an audio gateway at all - it would only charge the battery (when it worked).
I designed a simple circuit board to take the place of the battery, using a ldo regulator to drop the 5v incoming to 3.8 volts for the main circuit. I have about 20uF of capacitance on the output side and I can’t hear any power supply noise making it through to the output. It may not be exactly the same scenario, but these are cheap enough that if it were me, I would just try it and see what happened.
Product WRL-10822 |
about a month ago
The issue is with command termination. When you send $$$ to get into command mode, you must not follow that sequence with a carriage return or line feed. It’s in the data sheet. I use cutecom on a linux laptop and can turn off line endings to get to command mode, but then I have to turn them back on to actually change the settings. It’s annoying that it works that way.
Just thought I’d let everyone know that these modules don’t work as advertised. There are numerous firmware issues with the 4.xx series update and Microchip isn’t responding to user submitted bug reports. I contacted them over a year ago reporting issues with the firmware and got no response. That was version 2.32 of the firmware. I resubmitted my bug report in late December and got a “let me check with the developers” response. After another month of back-and-forth, my bug report is inexplicably closed and the firmware is not fixed.
Among the issues noted:
- module spontaneously resets for no reason
- loss of all settings after spontaneous reboot
- UDP broadcast of GPIO states is non functional
- Loss of TCP connection state causes remote connection errors until the session times out
In short, these modules are beyond unreliable. I would not recommend these as a solution in any project and Microchip doesn’t seem to care.
Product WRL-12030 |
about 5 months ago
Anyone know if these will detect the presence/absence of a 915Mhz carrier? If so, then you have my full attention because that’s the transmission mode used by my electrical meter. It would be real nice to monitor power usage wirelessly, but I haven’t been able to find anything handling carrier/no carrier transmission other than possibly GNU Radio. Seems like everything in that band is FSK.
Product BOB-11736 |
about 10 months ago
It would be nice if these boards actually came with a header for a real jumper rather than solder traces/bridges. I’m lazy and when I need to switch from 3.3v to 5v, I’m not really looking forward to the extra work of solder/desolder to get what I want. ;-) It only requires about 0.4 inches of board real estate (well, you could use smaller headers too, I suppose) and I’m even willing to take the time to install the header myself.
My other FT232 boards are voltage selectable via some wire-wrap connections, but that can be error prone if you’re not double-checking your work.
News - 3D Models of SparkFun Par… |
I wish people were as excited about spice circuit analysis as they are about 3D modeling programs. My last project which admittedly needs a good writeup, was designed entirely in LTSpice. No prototypes. If that didn’t sink in: NO PROTOTYPES. Just design, model, and make the final circuit board in one shot. Worked perfectly the first time.
News - According to Pete - The T… |
It will make the tardis sound automatically if you are both going at exactly 22mph relative to the time vortex and the car is also bigger on the inside. ;-) The hard part is, of course, being able to see where the time vortex is…
News - According to Pete - Filte… |
about a year ago
Great video. I studied this stuff about 20ish years ago in college and understood it really well. When I went off to a real job, I was working on a circuit that had a problem with electrical noise causing the gate of a mosfet to turn on partially, which led to failure of the part due to power dissipation issues.
The lead engineer was working on a fix and asked me to test his ‘fix’, which was to put a bigger mosfet into the circuit. Well, in case you don’t know, bigger mosfets have bigger coupling capacitances between their terminals. I knew from the get go it wouldn’t work, but this circuit was his baby and he wouldn’t listen to me.
Finally went to the head of the department and handed them a spice simulation of the effect of increasing the capacitances by way of this fix. I also recommended adding decoupling capacitance to the power rails of the circuit to get rid of the noise. He listened, agreed with me, then did nothing about it.
About a month and a half later, I was talking to another engineer and found out he was assigned to work on fixing the noise on the power rails.
Anyway - the video really brought back some memories. I don’t think I’d complain if you wanted to go more in depth with it, even though its a huge subject…
News - Welcoming Our New Robot F… |
about a year ago
FYI, your RSS feed is translating special characters (‘) into a horrible mess. It looks as though someone is writing the posts on a Mac, expecting someone on a PC to read it. This post is by far the worst I’ve seen so far. Special characters turn out looking like a typewriter barfed on the page ;-)
No public wish lists :(