Electrical Engineering V2 - Developers

OK my one day off of the week begins. Now to perform the backlog of things I want to do. Such as hook up my pile of ATtiny84s to my pile of DHT22s and NRF24L01+s.

I've had a thought in my head, but I haven't been able to put it into words until now. LEDs and lamps are the best educational tools in electronics, because most of us have 2 fairly decent photon detectors, and we're probably hardwired for vibrant, bright colours.

[QUOTE=nikomo;46318289]I've had a thought in my head, but I haven't been able to put it into words until now. LEDs and lamps are the best educational tools in electronics, because most of us have 2 fairly decent photon detectors, and we're probably hardwired for vibrant, bright colours.[/QUOTE] Or because they're cheap and easy.

Also that. A multimeter would do the job, and it's trivially reusable, but LEDs are more fun. Also, aaah weekend. Might actually get something done now.

FTDI has backpedalled on their new driver which bricked counterfeit chips. Now their new driver just refuses to talk to fake chips.

Doesn't matter, I'll now forever remember how stupid FTDI is.

[QUOTE=pentium;46320218]FTDI has backpedalled on their new driver which bricked counterfeit chips. Now their new driver just refuses to talk to fake chips.[/QUOTE] Atleast their are still more viable alternatives, i.e. AVR V-USB.

cant wait until some american is going to proceed against ftdi. if they dont want to get copied by the chinese, just lower the price.. 3$ per chip is rip off

[QUOTE=gamerpaddy;46322589]cant wait until some american is going to proceed against ftdi. if they dont want to get copied by the chinese, just lower the price.. 3$ per chip is rip off[/QUOTE] I know right? its cheaper to buy an atmel chip and flash it to do the same thing, like the arduino does.

[QUOTE=nuttyboffin;46323062]I know right? its cheaper to buy an atmel chip and flash it to do the same thing, like the arduino does.[/QUOTE] That has some drawbacks, most importantly limited speed. FTDI's USB-UART isn't really that expensive, £1.54 each in DFN-12 on Farnell compared with the similar MCP2200 for £1.50 in SOIC, sure you can get Chinese clones but eh you get what you pay for.

[QUOTE=pentium;46320218]FTDI has backpedalled on their new driver which bricked counterfeit chips. Now their new driver just refuses to talk to fake chips.[/QUOTE] does this mean chinese clone arduino's (i.e. nano) are not connectable?

What a great time to switch to GNU/Linux!

Windows, we don't go there anymore.

If a datasheet says 0.1 uF for the power supply filtering caps, can I use 1 uF instead? I don't have any 0.1 uF caps on hand and can't be bothered to order some.

Has anyone here had experience driving Adafruit Neopixels with an attiny85? I made a little protoboard to work with this combo and it only seems to light up one single LED with green, then after a few seconds that changes to yellow, then a few seconds after it goes white and stays that way. I know the attiny85 is programming correctly because I can get a blink sketch running fine and I know the neopixel code is ok because it works on an arduino leonardo. Any ideas?

-snip- there already are tutorials to fixing bricked FTDI's

[QUOTE=ManxKat;46327584]If a datasheet says 0.1 uF for the power supply filtering caps, can I use 1 uF instead? I don't have any 0.1 uF caps on hand and can't be bothered to order some.[/QUOTE] You could but it's certainly not advisable, particularly if you're thinking of using an electrolytic, depends on what the supply is used for though, if it's something sensitive you really want to use a ceramic MLC or plastic film.

[QUOTE=ManxKat;46327584]If a datasheet says 0.1 uF for the power supply filtering caps, can I use 1 uF instead? I don't have any 0.1 uF caps on hand and can't be bothered to order some.[/QUOTE] It honestly depends upon the sensitivity, type of load. If you have a rather sensitive RF/HF circuit, you'll probably need the lower value caps to shunt any high frequency noise (In which case, you could probably just put a few 1uFs in series to get 0.1uF). If not, you should be good with a 1uF.

[QUOTE=Chryseus;46327922]You could but it's certainly not advisable, particularly if you're thinking of using an electrolytic, depends on what the supply is used for though, if it's something sensitive you really want to use a ceramic MLC or plastic film.[/QUOTE] Thanks. It's for a AS5013 magnetic joystick IC so I guess it is somewhat sensitive. Luckily I found some 0.1uF 0402 ceramic caps. I hope they'll fit the 0603 pads.

[QUOTE=ManxKat;46327584]If a datasheet says 0.1 uF for the power supply filtering caps, can I use 1 uF instead? I don't have any 0.1 uF caps on hand and can't be bothered to order some.[/QUOTE] Read the datasheet. It'll say something like 0.1u minimum capacity. But generally one could say that more is better.

[QUOTE=DrDevil;46328003]Read the datasheet. It'll say something like 0.1u minimum capacity. But generally one could say that more is better.[/QUOTE] Generally speaking yes but not always, ESR tends to rise with value among the same capacitor type so the gain in capacitance is offset by the increased ESR, this also ends up increasing thermal noise, although this is only really a concern in extremely sensitive circuits, there is also a risk of unwanted resonance which could cause issues particularly in high frequency circuits. Although in this case I don't think it would matter at all.

Man, all this RF stuff looks beautiful. [url=http://i.imgur.com/4fhTg2J.jpg][img]http://i.imgur.com/4fhTg2Jl.jpg[/img][/url] Working on a HP 8444A Opt 059 tracking generator for my spectrum analyzer, it has some ALC problems.

I was hurting really badly for a digital storage scope to track down a fault but have nothing of the likes. Oh look, a use for that HP 3960 recorder I got in August. :dance: [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_7084.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_7085-1.jpg[/IMG] Now I can review the captured data at original, 1/4, or 1/15 speed.

[QUOTE=pentium;46330734]I was hurting really badly for a digital storage scope to track down a fault but have nothing of the likes. Oh look, a use for that HP 3960 recorder I got in August. :dance: [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_7084.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_7085-1.jpg[/IMG] Now I can review the captured data at original, 1/4, or 1/15 speed.[/QUOTE] Its really mind boggling how that entire thing, all of those PCBs and chips in there... could likely fit onto somthing around the size of a credit card now.

[QUOTE=HiddenMyst;46327678]Has anyone here had experience driving Adafruit Neopixels with an attiny85? I made a little protoboard to work with this combo and it only seems to light up one single LED with green, then after a few seconds that changes to yellow, then a few seconds after it goes white and stays that way. I know the attiny85 is programming correctly because I can get a blink sketch running fine and I know the neopixel code is ok because it works on an arduino leonardo. Any ideas?[/QUOTE] I fixed the problem. For future reference, don't forget to burn the bootloader.

The fruits of my labor: [t]https://dl.dropboxusercontent.com/u/62766551/PA260018.jpg[/t] I wrote a neopixel clock that's driven by an ATtiny85. Currently it has a few problems because I am deciding each tick by checking how many milliseconds have passed since the previous tick, which has lead to it being about 2 ticks fast per minute. There's also the fact that it is blindingly bright, but I will add a diffuser when I make a case for it.

[QUOTE=Chryseus;46323496]That has some drawbacks, most importantly limited speed. FTDI's USB-UART isn't really that expensive, £1.54 each in DFN-12 on Farnell compared with the similar MCP2200 for £1.50 in SOIC, sure you can get Chinese clones but eh you get what you pay for.[/QUOTE] Most designs use FTDI's chip because it has WHQL drivers that will be automatically installed on Windows once you connect your device to the computer. As far as I remember, the MCP2200 needs a manual driver install.

[QUOTE=alexaz;46334595]Most designs use FTDI's chip because it has WHQL drivers that will be automatically installed on Windows once you connect your device to the computer. As far as I remember, the MCP2200 needs a manual driver install.[/QUOTE] I did not consider that, the MCP2200 VCP driver also appears to be unsigned which is no good at all for Windows 8, that leaves the FTDI chip as the most cost effective at least for their DFN-12 package, the SSOP has a ridiculous markup (£4), the CP2102 would be another possible choice at £2.76 each in MLP-28. Although really if you need USB your best bet is to use a micro that has USB built in, the ATXMEGA16A4U for example only costs £2.15 in TQFP-44.

[QUOTE=HiddenMyst;46334448]The fruits of my labor: [t]https://dl.dropboxusercontent.com/u/62766551/PA260018.jpg[/t] I wrote a neopixel clock that's driven by an ATtiny85. Currently it has a few problems because I am deciding each tick by checking how many milliseconds have passed since the previous tick, which has lead to it being about 2 ticks fast per minute. There's also the fact that it is blindingly bright, but I will add a diffuser when I make a case for it.[/QUOTE] can't you just like half the RGB values for the bright LED's when using the neopixel library?

Finally got to work with the STM32 Nucleo boards! Using the 100 Mhz F411RE as it did way better serial baud rate than the L152RE. This took so long to make :( [IMG]https://dl.dropboxusercontent.com/u/100328/Facepunch/output_P6sdmz.gif[/IMG] I'm going to connect 5 more Nucleo boards as i2c slaves, these slaves will acts as controllers - so that they can bet on a number. omg i just realised that I have a error in the gif..