Powerocks Magicstick Review

One thing about having a blog (I have a few)  is you sometimes get email asking you to review a product,  I normally shit-can those requests.  It’s not that I have some high ethical standards, but normally it is a product or service I have no interest in.

A couple weeks ago I got an email about the Powerocks Magicstick.  I mentally giggled because you know “magic stick”.  I browsed the email and did a quick search and it turns out that it is a spare battery USB charger thingie.  I have a few of these and most of them suck.  Granted I didn’t buy high end ones, but I paid as much as  they are asking for the Magicstick.  The problem I have with most of the chargers is the brick design and cheap switches.

Anyway,  I responded to the email and said something along the lines of, “I like free shit, send me one and I will write something up about it.”  My plan was this,  if I liked it I would write something positive and send the company the link.  If I did not like it I would write something up and send the company the link.  I was kind of hoping it sucked because writing a bad review is fun!  Turns out I liked the design and the damn thing worked.

So what do you get?  This:

I mean it comes in a box but I recycled that.  It was a decent box.  Inside though is a Magicstick, MicroUSB cable and a pouch.  The stick itself is some sort of metal,  it feels really solid.  It has a 2800mAh battery so it will give you a good long charge.  The pouch is good to put catnip in.

Charge up the stick by plugging the MicroUSB end into the charger and the other end into a computer or wall USB port.  Once charged you just plug your device into the Magicstick.  Want to know how much juice the Magicstick has?  Press the button on one end and the RGB LED will light up,  Red means low, Green is 30-70% left, Blue is 71% and above.  It’s dirt simple and small.

My testing was to see how well it charged some devices, mainly my collection of phones.  On the Galaxy Nexus I ran the phone to 48% battery.  I put the POwerocks on the phone and left the house.  Using my bluetooth headphones and streaming music from Google All Access it added 6% to the phone battery in about an hour.  I was pleased,  as someone that walks a lot I do burn some battery so having something to keep it boosted helps.

The other tests I ran were un-timed.  I left for work with an almost dead LG Optimus S sitting on a fully charged Magicstick.  The phone fully charged and there was a juice left on the charger (it was still green).  The Optimus battery is 1300mAh so this makes sense,  it also tells me that chances are the cells in the Magicstick are as advertised.

If you want to get one you can find them at the usual places like Amazon and Ebay.

Posted in: Uncategorized by Chuck No Comments

Arduino based Game Show Buzzer in an Altoid Tin

The sales people where I work have a weekly meeting and they have decided to have contests in these meetings.

Being a competitive group they needed a system to decide who “raised their hand” first to answer a question.  This of course leads to the use of the Game Show type buzzer system.

Arduino Gameshow Buzzer in an Altoid Tin

Arduino Gameshow Buzzer in an Altoid Tin

Two things need to happen in this system.  There must an indicator to show someone buzzed in and second,  any other buzz ins after the first must be ignored.  Seems simple enough.

For my system I only needed 4 inputs and one additional button to allow the host to reset the system.

Relays or discreet logic could be used to handle all of this.  I was however under a time crunch and a cost crunch so I went the Arduino route.  Looking at all of the parts involved I think this was done for under $20.  The most expensive things were the momentary pushbuttons, but those were “free” as they came from parts from an old radio broadcast console.

Arduino Gameshow Buzzer in an Altoid Tin

Arduino Gameshow Buzzer in an Altoid Tin

For a case I decided that an Altoid tin would be fine.  I had one sitting around and I only needed space to connect the buttons and to display the results via LED.  The handles of the pushbuttons were cut from a piece of conduit (about 4 inches/10cm long).  The pushbuttons were wired to the control box via a DB9 connector.  This allows for the 5 pushbuttons I needed (4 contestant, one reset) .  I used pins 1-5 for the button and pins 6-9 as a common.

Arduino Gameshow Buzzer in an Altoid Tin

With the construction in hand the electronics are next.  All there is to this project is a barebones Arduino, some limiting resistors on the LED outputs, a few LEDs and a 5V regulator.  In the picture you can see a fifth LED in the case.  This was the pin 13 LED that I usually put in projects for testing the barebones build.

Arduino Gameshow Buzzer Schematic

Arduino Gameshow Buzzer Schematic

The software is equally easy to put together.  Scan the 4 lines to see if they go low (I used the internal pull-up resistors to make the circuit easier), if a line goes low light an LED and then go into an endless loop of nothing to basically end the program.  To start again you reset the Arduino.  This is not shown in the schematic but it is done by pulling pin 1 low.

int button1 = 0;

int button2 = 0;
int button3 = 0;
int button4 = 0;
int chuck =1;
void setup() {

pinMode(13, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
pinMode(8, OUTPUT);
pinMode(9, INPUT);
pinMode(10, INPUT);
pinMode(11, INPUT);
pinMode(12, INPUT);}

void loop() {
digitalWrite(9, HIGH);
digitalWrite(10, HIGH);
digitalWrite(11, HIGH);
digitalWrite(12, HIGH);

digitalWrite(5, HIGH);
delay (200);
digitalWrite(5, LOW);
delay (200);
digitalWrite(6, HIGH);
delay (200);
digitalWrite(6, LOW);
delay (200);
digitalWrite(7, HIGH);
delay (200);
digitalWrite(7, LOW);
delay (200);
digitalWrite(8, HIGH);
delay (200);
digitalWrite(8, LOW);
delay (200);

while (chuck=1){
button1 = digitalRead(9);
button2 = digitalRead(10);
button3 = digitalRead(11);
button4 = digitalRead(12);
if (button1 == LOW) {
digitalWrite(5, HIGH);
while(1) {
}
} // set the LED on
if (button2 == LOW) {
digitalWrite(6, HIGH);
while(1) {
}
} // set the LED on’
if (button3 == LOW) {
digitalWrite(7, HIGH);
while(1) {
}
} // set the LED on
if (button4 == LOW) {
digitalWrite(8, HIGH);
while(1) {
}
} // set the LED on
}
}

With some testing I found that the reset takes 1-2 seconds.  While you are waiting you of course cannot buzz in.  To let the users know the system is ready I added the quick LED scroll.  This of course increases the time between reset and “ready to go” but it does let the user know that things the system is running and that each LED does in fact light up.

http://www.youtube.com/watch?v=8UfxOmglSBg

In looking into the ways other people created these systems I noticed a few people talking about ties.  This is nothing that I worry about.  If I was setting up a real contest I would be, but these are coworkers and the chance of getting sued is low :)

Posted in: Uncategorized by Chuck 17 Comments

Time Lapse Sample

I am getting ready to revisit the revisions/improvements to my Time Lapse Setup so I did a quick test yesterday.

 

Time Lapse Test

Time Lapse Test

 

 

Using a Max232 with an Arduino

Max232 On Board

Max232 On Board

I never said my work was pretty.

The Nintendo Button board got a new addition the other day,  a Max232 chip.

I am a big fan of the RS232 serial port. I work in broadcast and a lot of the gear I use have the ports. You use them to configure everything from EAS ENDECS to Satellite receivers to Audio Consoles. Slowly but surely

USB and more likely IP ports are replacing the RS232 port. Sometimes it is a blessing, other times it leads to graphical interfaces that make me yearn for a simple command line.

That is besides the point though, this post is about using the Max232 chip and an Arduino. If you ever tried just hooking an Arduino to a computer’s RS232 port you will note that it does not work, that is because the voltage levels are not compatible, in fact you can end up frying the Arduino because the RS232 port using a much higher voltage. To solve this you need something to bridge the gap.

Max232 On Board

Max232 On Board

If you have an Uno or a shield they normally just hook you up with a USB port, it is plug and play, perfect. Once you start building things and ditching the shield you will find you need a way to communicate. Normally you just get a USB to TTL convertor and hook it up. I have a few of them and they only cost $8 on Ebay. This becomes expensive if you want to have a port on a project (for data capture, on the fly programming, etc..)

My solution and a lot of people’s solution is the Max232 chip. Put this IC in play and you will be able to connect the Arduino to a RS232 port or USB RS232 cable. Program the Arduino, collect data, knock yourself out. I picked up 10 of them on Ebay for about $10. Make sure to get some 1uF or 10uF capacitors while you are at it, you will need a few to make the circuit work.

Max232 Schematic

Max232 Schematic

Please excuse the mess of a schematic. I decided to just scan from my notebook instead of creating the drawing in gEDA Schematic Editor. It is pretty basic so hopefully it will do. Please note I think I got the pins right, I sometimes forget to make the changes on my notes. If something is not working try reversing the TX and RX pins.