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1  Community / Exhibition / Gallery / Re: Tiny84(duino) on: November 30, 2012, 04:06:09 am
Ive been plugging and unplugging with the power on . As long as the programming has finished it does not seem to do any harm. Probably reaching 1000 plug ins and pull outs this way with no bad results.

But then I am more of a risk taker than most
2  Community / Exhibition / Gallery / Re: Tiny84(duino) on: November 29, 2012, 06:55:33 am
I was thinking of using one of those sockets and just wiring up 8 pins say at the top end
That way I could add to it later if need be I have one 6 pin plug with wires sprouting everywhere plugged into a small breadboard at present but I'm always putting the chip in the wrong holes!

I just leave it all attached to the usbtiny programmer so I was looking to tidy that up

3  Community / Exhibition / Gallery / Re: Mechanical Bass Guitar on: November 28, 2012, 06:26:45 am
Go to it guys
If you can make music like the first post youve got it made. I am trying to copy it now

Just a Jaw-dropping bass.
4  Community / Exhibition / Gallery / Re: Graphic Speedometer on: November 28, 2012, 06:24:19 am
Hey man just a joke -could not resist .

Really a lovely bike Can I go for a ride?
5  Community / Exhibition / Gallery / Re: Moving lights with a 74HC595 shift register on: November 24, 2012, 10:19:51 pm
the most annoying thing about startup web sites is that they repeat the same stuff over and over and over....enough
6  Using Arduino / LEDs and Multiplexing / Re: Using LEDs as a light/dark sensor on: November 23, 2012, 11:12:10 pm
I'm getting huge differences in different types of LED's
The small 3 mm seem unuseable if I have them on extension wires which I need to mount through the container for waterproofing purposes.

the 5mm is much better but again varies drasticaly when you extend it . The capacitance varies with the extension leads I suppose..Using your hands to shade them often changes its capacitance greatly  as does heat.

They don't look like something I can reliably use at this point.
7  Using Arduino / LEDs and Multiplexing / Re: 200ohms potenciometer as analog input, Arduino UNO on: November 20, 2012, 03:02:27 am
Quote
Maybe it hasnt but I think it does.
You can think what you want, but you can't alter the laws of physics by thinking. So while you think that is the problem I am telling you that it is not.
More important I think that thinking helps us determine what the laws of physics are and we certainly do not have them all right yet!
8  Community / Exhibition / Gallery / Re: Graphic Speedometer on: November 19, 2012, 11:46:04 pm

Here is his current vehicle . OBD2 will soon be installed on all the newer models
9  Community / Exhibition / Gallery / Re: Auduino Fix + Delay on: November 18, 2012, 01:28:48 am
Hi,
   Its not the speaker thats at risk, its the Arduino. The 40ma limit is the most that a pin will safely output, it will output more if you let it, but it will die in the process. It will look like your getting away with it, but you are not, your damaging your chip and at some point the output pin will stop working.Are you sure about that? Thats not how I understand it . The USB port sets the current to the arduino at a set amount. (200mA? not sure atm). I thought each pin could not supply or sink any more than 40mAs ?

   I am not sure that the 318 op amp is a solution, its more of a voltage amplifier than an current amplifier. Yes, but it was all I had and it did not work. Just something to try as I won't get the right one for a week.

   If you don't have an LM386, you can try a simple resistor and capacitor network to send the output to an mp3 player or anything else with an Aux input - the circuit is shown in the Illutron B link above.I tried this to a 100 ohm resistor but it just reduced it more . With a 16 ohm impedence speaker it would take 300mA at most at this voltage (3.3V), the 100 ohm resistance droped this again

Duane B

Just a quick squiz at the datasheet for my ATMega328 and I have the (p) model which is low power I think
Quote
29. Electrical characteristics
29.1
Absolute maximum ratings*
Operating temperature................................... -55°C to +125°C
*NOTICE:
Storage temperature...................................... -65°C to +150°C
Voltage on any pin except RESET
with respect to ground .................................-0.5V to VCC+0.5V
Voltage on RESET with respect to ground ......-0.5V to +13.0V
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.
Maximum operating voltage.............................................. 6.0V
DC current per I/O pin.................................................. 40.0mA
DC current VCC and GND pins ..................................

So if anybody knows for sure please jump in . It stands to reason that perhaps certain chips can push more than 40mA's but I would like to know for sure.
10  Community / Exhibition / Gallery / Re: Auduino Fix + Delay on: November 17, 2012, 05:39:50 pm
I used a 16 Ohm speaker I had lying about and tried a 100 Ohm resistor in series but it just weakened the tune .
You can hear that some notes are going well past the range of the speaker

The ATMega328  microController only puts out 40 mAmps on each output pin so its pretty safe atm I suppose.
I'm just building your 386 amp but only have a LM318N atm .That will do for a test but its pinouts are reversed
11  Using Arduino / Networking, Protocols, and Devices / Open and watch two or more terminals at the same time on: November 17, 2012, 04:56:56 pm
(Not sure if this is the right place so a mod might move it if necessary.)

I see a Python module to run as many terminals as you need to watch inside just one so you can send a message to your transmitter ands watch what the receiver gets . Good for debugging receiver /transmitter stuff and other things .
You need to have python 2 or 3  and I noticed my python 2 did not have the argparse module so I had to get it to make it run.
Each serial input is in its own colour and you can change them by swaping the colour list in the script

See more about it here http://jdonnal.scripts.mit.edu/home/?p=135
12  Community / Exhibition / Gallery / Re: A new IMU which I'm thinking of calling openIMU on: November 17, 2012, 02:51:56 pm
Its always good to explain what letters such as these mean .
There are many possibles
http://en.wikipedia.org/wiki/IMU

I suspect in this case it is
Inertial measurement unit
13  Community / Exhibition / Gallery / Re: Auduino Fix + Delay on: November 15, 2012, 06:16:28 pm
Hours and hours of fun -Thanks
I just downloaded the code ,put it on a 328p then
I put a speaker on D3 /ground and a loose wire in A0
Holding the wire produced a pretty good sound to get me started
14  Using Arduino / Programming Questions / Adjust LCD/LED brightness by reading from an LED on: November 15, 2012, 04:19:43 am
I came across this bit of code and am struggling to understand it
Can anyone explain the registers involved and what is being done to them ?
I would like to get it to compile and run in something



Code:
//*********************************************************
void adjustBrightness(void) {
char brightness ;
unsigned char adc_reading = ADCH;
ADCSRA |= (1<<ADSC); //Turn back on the ADC

if (adc_reading < 25) brightness = 16;
else if (adc_reading < 70) brightness = 15;
else if (adc_reading < 125) brightness = 14;
else if (adc_reading < 170) brightness = 13;
else if (adc_reading < 200) brightness = 12;
else brightness = 11;

PORTB = PORTB & ~(1<<DAC_CS);
    WriteByteSPI(0b011110000);
    WriteByteSPI(0x00);
    PORTB = PORTB | (1<<DAC_CS);

    _delay_us(5);

    PORTB = PORTB & ~(1<<DAC_CS);
    WriteByteSPI(0b11110000 | ((0xA - (brightness >> 3)) & 0x000F));
    WriteByteSPI(~(brightness & 7) << 5);
    PORTB = PORTB | (1<<DAC_CS);

}

You might like to know what this is in see
Quote
Brightness Auto Adjust

In running state, the program will adjust the brightness of the seven-segment LEDs automatically according to the environment brightness. If the room is bright, the program will light up the LEDs more. If the room is dark, the program will dim the LEDs. The following function is called:

    void adjustBrightness(void): This function reads the high bits value of the Analog-Digital Converter. Then it adjusts the value of the brightness global variable according to the ADC value. The calibrated brightness will be written to the DAC using WriteByteSPI. The DAC will power the LED drivers with the calibrated voltage and thus control brightness.

at this site
http://people.ece.cornell.edu/land/courses/ece4760/FinalProjects/s2012/aab85_tz54/aab85_tz54/index.html
15  Using Arduino / LEDs and Multiplexing / Re: LEDs as Photo-diodes on: November 14, 2012, 03:16:31 pm
Add this:
Code:
#define NOP() asm("nop") //waste a tick
delay(400) is way too long. If you have to, use delay(1)

Yes OK but I was trying to see just what you are getting at. By slowing it down some as I said it is just alternate flashing LED's . The serial monitor flashes values too fast to read anything definate.

So with a small delay , what is this going to demonstrate to me ?
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