[QUOTE=Chryseus;30409716]Electrons flow from negative to positive, current (conventionally) flows from positive to negative.
In NPN transistors current normally flows from collector to emitter, with the base being positive WRT emitter, with
PNP transistors current flows from the emitter to collector with the base being negative WRT collector.
Have a look at [url=http://www.falstad.com/circuit/#%24+1+5.0E-6+10.20027730826997+45+5.0+50%0At+240+144+272+144+0+1+-4.215442223939027+0.7845577760609729+100.0%0Ag+272+192+272+224+0%0AR+272+128+272+96+0+0+40.0+5.0+0.0+0.0+0.5%0Av+176+176+176+144+0+0+40.0+5.0+0.0+0.0+0.5%0Aw+272+192+176+192+0%0Aw+176+192+176+176+0%0Aw+272+192+272+160+0%0Ar+240+144+176+144+0+100.0%0Ar+416+144+352+144+0+100.0%0Aw+448+192+448+160+0%0Aw+352+160+352+144+0%0AR+448+128+448+96+0+0+40.0+5.0+0.0+0.0+0.5%0Ag+448+192+448+224+0%0At+416+144+448+144+0+-1+4.195942028932162+-0.8040579710678379+100.0%0Av+352+160+352+192+0+0+40.0+5.0+0.0+0.0+0.5%0Aw+352+192+448+192+0%0At+336+384+368+384+1+-1+4.195942028932162+-0.8040579710678379+100.0%0AR+368+400+368+432+0+0+40.0+5.0+0.0+0.0+0.5%0Ar+336+384+272+384+0+100.0%0Av+272+368+272+336+0+0+40.0+5.0+0.0+0.0+0.5%0Aw+272+384+272+368+0%0Aw+368+368+368+336+0%0Aw+368+336+272+336+0%0Ag+368+336+368+304+0%0Ax+168+270+280+274+0+14+NPN+Current+Flow%0Ax+266+467+378+471+0+14+PNP+Current+Flow%0Ax+354+276+521+280+0+14+PNP+Inverted+Current+Flow%0A]this.[/url]
A simple method to remember the correct arrow direction on the BJT transistor symbol is to remember NPN = 'Not Pointing In'.[/QUOTE]
It all makes sense now O.o
Thanks!
Hmm. I've done some more testing after opening up the PSU and cleaning it out, and 3.3v seems stable. PG however is never pulled high. I suspect this is why the system never boots, but since all of the voltages are within spec I have no idea why it is not pulled high. Any ideas?
Edit:
Ah, 3.3v is settling at 3.38 volts, 0.04v above spec. I guess this should drop once load is applied, but if PG is never pulled high then no load will be applied. fff
I wonder if it would be physically possible to create a Portal like dynamic test chamber system, at least in miniature. That would be awesome.
Are there any tutorials on how to reprogram the chip on the Arduino to make it behave as a generic USB HID?
[QUOTE=Overv;30418983]I wonder if it would be physically possible to create a Portal like dynamic test chamber system, at least in miniature. That would be awesome.[/QUOTE]
I think miniature would be harder than a bigger scale here.
[media]http://www.youtube.com/watch?v=Pndk215HJLc[/media]
Finally got my servo for the rangefinder mounted
WIN.
Now do a 360* lidar and pathfinding and have it bump into random people :D
Just got my Uno in the post! Can I please get added to the list?
[QUOTE=Iskuri;30446408]Just got my Uno in the post! Can I please get added to the list?[/QUOTE]
Done.
[QUOTE=AGMadsAG;30426594][media]http://www.youtube.com/watch?v=Pndk215HJLc[/media]
Finally got my servo for the rangefinder mounted[/QUOTE]
I find it cute when it looks round both ways before it makes a dissection. :3:
[QUOTE=AGMadsAG;30426594][media]http://www.youtube.com/watch?v=Pndk215HJLc[/media]
Finally got my servo for the rangefinder mounted[/QUOTE]
That's really cool, but I think you have it turn a wider angle than it "scans"? This leads to it over shooting the gap in the obstacles.
[QUOTE=Chryseus;30409716]Electrons flow from negative to positive, current (conventionally) flows from positive to negative.[/QUOTE]
You got this a little backwards, current flow = electron flow (negative to positive). Positive to negative is voltage potential: Negative charge means more electrons, positive charge means less electrons, electrons travel from negative to positive to try and "balance out" the charge differences, resulting in current.
[QUOTE=Zero-Point;30454092]You got this a little backwards, current flow = electron flow (negative to positive). Positive to negative is voltage potential: Negative charge means more electrons, positive charge means less electrons, electrons travel from negative to positive to try and "balance out" the charge differences, resulting in current.[/QUOTE]
I did say conventionally, technically yes current is negative to positive but following convention as most books and people do current is considered to move positive to negative.
It really does not matter which way you use as long as you stick with it, although certain devices such as transistor and tubes are generally easier to understand from the electron viewpoint.
If only we got it right in the first place...
Seeing electricity the technical way is the better way, because that way you have an energy current instead of an electron current.
[QUOTE=Shrapnel :3;30450097]That's really cool, but I think you have it turn a wider angle than it "scans"? This leads to it over shooting the gap in the obstacles.[/QUOTE]
Thanks!
Well, it is going to follow a black tape on the floor, and I am only going to use the rangefinder for a couple tasks.
And thanks for all the comments guys!
[QUOTE=DrLuke;30459670]Seeing electricity the technical way is the better way, because that way you have an energy current instead of an electron current.[/QUOTE]
For you and anyone else confused about voltage, charge and electrons I highly
suggest reading [url=http://www.mediafire.com/file/m3ruj97e3ms39lv/sefton.pdf]this[/url].
[QUOTE=ruarai;30466365]I have had my arduino for a while, learnt the basics and such.
I just now want an idea to do that would be moderately hard and fun.
[editline]15th June 2011[/editline]
Also add me to the list of owners thanks[/QUOTE]
What Arduino board are you using ?
Generally you don't need to think of electricity in terms of electrons and charge. Current and voltage are fine.
With a bit of tinkering, I've gotten my router to act as a serial-to-telnet proxy for my Arduino! Who needs ethernet shields? :v:
[QUOTE=Lapsus;30489303]With a bit of tinkering, I've gotten my router to act as a serial-to-telnet proxy for my Arduino! Who needs ethernet shields? :v:[/QUOTE]
Setup pics?
Hey guys, got a quick question, I'm trying to pick up an infra red signal with my arduino, I am fairly new to this so am having a small issue. I have connected an ir phototransistor to the 5v and A0 ports on my arduino and have relayed the data to the serial monitor. When I have the cables attached one way there is a constant 1023 being outputted, and swapped around it shows 940-950 fluctuating around, either way around it does not make any changes even when I am aiming an infra red transmitter at it, that is working. Can anyone give me any advice on why it isn't working?
EDIT: I worked it out, as it turns out the change in power is ridiculously subtle, when aiming the tv remote at it and pressing a button, it only has a change of around 4-8.
Does anyone have any recommendations as to where to buy electronic components from? Right now I'm mainly looking to buy a bunch of servos that are small and have a large range of motion. I found an online servo shop for RC models which are cheap, such as [url=http://www.servoshop.co.uk/index.php?pid=RIPPNEWXL02XL2&area=Servo]this one[/url] however it only turns 60 degrees.
Preferably UK based to minimise postal costs. What do you guys use?
[QUOTE=JSharpe;30514788]Does anyone have any recommendations as to where to buy electronic components from? Right now I'm mainly looking to buy a bunch of servos that are small and have a large range of motion. I found an online servo shop for RC models which are cheap, such as [url=http://www.servoshop.co.uk/index.php?pid=RIPPNEWXL02XL2&area=Servo]this one[/url] however it only turns 60 degrees.
Preferably UK based to minimise postal costs. What do you guys use?[/QUOTE]
Dealextreme has some
Hobbyking also carries some, but shipping is a tad expensive there
OK new question. I've wired up an n64 controller to the arduino (it's an uno) and am trying to gather data from it on button presses. After reading up on it I have learnt that it sends serial data through the middle every few microseconds. Now, I haven't gotten to the procuring of each separate bit, or the analog data, but when it is all hooked up and I use an analog input i get a constant fluctuation around the 640 range in the serial monitor, which doesnt change at all if i press any buttons etc, and in the digital input it just outputs 1 and never 0 or anything. Is there something I am doing wrong? I am literally just hooking up the 3.3v pin to the 3.3v on the arduino, the serial pin to the analog in/digital in and the ground to the ground.
I am still looking for the website that I found a while ago which explained it perfectly but the n64 controller needs a trigger to send something back, so you send a certain command through the data port to it and it responds with a certain signal. (still trying to find the protocols)
[editline]17th June 2011[/editline]
Oke so the website that I was looking for is down : [url]http://www.mixdown.ca/n64dev/[/url]
But I think the gamecube protocol looks allot like it, so you could use that to try and reverse engineer it : [url]http://www.int03.co.uk/crema/hardware/gamecube/gc-control.htm[/url]
[QUOTE=JSharpe;30514788]Does anyone have any recommendations as to where to buy electronic components from? Right now I'm mainly looking to buy a bunch of servos that are small and have a large range of motion. I found an online servo shop for RC models which are cheap, such as [url=http://www.servoshop.co.uk/index.php?pid=RIPPNEWXL02XL2&area=Servo]this one[/url] however it only turns 60 degrees.
Preferably UK based to minimise postal costs. What do you guys use?[/QUOTE]
Outside of the likes of RS, Rapid and Farnell, I highly recommend using eBay for parts. Overall I've found great deals, niche parts and some great services. Of course it'll vary between seller but if you're willing to do a little digging, you should be able to find what you need.
[QUOTE=Iskuri;30517524]OK new question. I've wired up an n64 controller to the arduino (it's an uno) and am trying to gather data from it on button presses. After reading up on it I have learnt that it sends serial data through the middle every few microseconds. Now, I haven't gotten to the procuring of each separate bit, or the analog data, but when it is all hooked up and I use an analog input i get a constant fluctuation around the 640 range in the serial monitor, which doesnt change at all if i press any buttons etc, and in the digital input it just outputs 1 and never 0 or anything. Is there something I am doing wrong? I am literally just hooking up the 3.3v pin to the 3.3v on the arduino, the serial pin to the analog in/digital in and the ground to the ground.[/QUOTE]
The N64 controller requires that you request the button information.
[url]http://inst.eecs.berkeley.edu/~cs150/fa04/Lab/Checkpoint1.PDF[/url] gives some info on how you do this.
Also you do not use the analog input to read serial data.
OK Chryseus, thanks a lot for that info, that page is certainly a good read, now I just need to work out whether the 4microseconds per bit is 4 microseconds for the whole sub bit setup and the actual bit or if it's 4 microseconds for each bit, sub or not.
I own an Arduino Uno!
[editline]18th June 2011[/editline]
I'm messing around a lot with a photoresistor. I'm going to setup a sensor to see if anyone is walking down the hall, and alert me if so.
I just got some great deals on eBay. Unfortunately a lot of it will be coming in 3-4 weeks which is a bummer.
After ordering some nice Panasonic caps for the powersupply of the TV and soldering it all (desoldering heatsinks sucks) the TV works again. Hooray.
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