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1  Using Arduino / Project Guidance / Re: Using Aruino Digital pins after putting on a motor shield on: July 26, 2014, 01:04:18 pm
I am by no means a very experienced arduino user... but I have used an MP3 playback shield in the past whilst simultaneously using an ultrasound was 3 years ago.... but I believe the unused pins on the shield can be used, and will 'pass' your signal straight through to the arduino beneath?

Please can someone verify this as correct?  smiley-confuse

2  Using Arduino / Project Guidance / Proximity sensor to DMX control on: July 26, 2014, 12:57:28 pm

For my new project - I need to turn on some main powered devices when somebody walks in to a specific area. I want to use my arduino (UNO) as a standalone unit to do this (no PC involved).

I want to use my SR05 to act as the proximity sensor (I have used it successfully to detect people's presence in the past).

I have a DMX controlled mains power relay to do the mains power switching.

I want arduino to read the distance from the sensor and send a high value on a DMX channel when someone is present (distance less than 1m), and to then send a low value to the DMX channel when the person leaves (distance returns to above 3m).

Can someone please recommend the most simple hardware / circuit to send a DMX signal?

Can someone advise on the most simple approach to the code?

Many Thanks in advance for your time,

3  Using Arduino / General Electronics / Re: high speed cmos question on: January 17, 2012, 08:44:39 am
Many thanks for the information.

the ic that is listed for the circuit is a CD4060BC. The closest I can find to buy at maplin is a HCF4060BE

Is this the right chip ?

Many Thanks
4  Using Arduino / General Electronics / high speed cmos question on: January 16, 2012, 06:34:50 pm

I am having problems with a circuit. It is shorting somewhere. I have just realised, I have accidentally used a high speed cmos chip instead of a 4000 series.

If I apply over 6v to a high speed cmos chip, (specifically the 74HC4060) could it short my circuit, and make the battery I am using to power the circuit feel hot to the touch?


5  Using Arduino / Project Guidance / Re: Large Steel Sheet as Capacitive Sensor on: January 04, 2012, 12:28:05 pm
Many Thanks Grumpy Mike for the reply,

from the old post :

I have used this circuit and because I didn't have a large enough resistor, I connected up an LDR.

I then got a smoothed value of 0 and 4 when I touched it. When I covered up the LDR, producing a massive resistance it would give me values of 100-200 when I was ~1m away and then increase to just over 1000 when I walked up to it.

I do take on board your comments regarding clarity of these sensing methods/claims.

I have rejected the ultrasonics method due to purely aesthetic reasons. This project is an artwork and I like the clean nature of using the steel sheet to pick up proximity. Ultrasonic sensors tend to look like little robot eyes smiley

I have been meaning to look in to the kinect for some time, however aesthetically it would be wrong for this piece.

Is it not possible to replace the 'aerial' in a theremin with my sheet of steel ?

6  Using Arduino / Project Guidance / Re: Large Steel Sheet as Capacitive Sensor on: January 04, 2012, 08:34:02 am
Thanks Grumpy Mike and PeterH,

On the old forum Mowcius mentioned using the method I described and getting 1m range, that's why I tried it. He was using a small piece of Aluminium foil though not a (relatively) massive sheet of steel. here:

I have read about projects with a 3m range but these indeed used 555 timers and I believe some sort of theremin type sensing, but it all gets very complicated for me when theremin circuits are mentioned,  smiley-red

I assume then that this 'theremin' type of sensing is not actually 'capacitive' sensing'? 

Perhaps someone could point me in the right direction?

7  Using Arduino / Project Guidance / Large Steel Sheet as Capacitive Sensor on: January 04, 2012, 06:58:00 am

I am currently working on a project that involves using a large (1m x 2m x 1mm thick) sheet of steel to sense the proximity of people via capacitive sensing. The senor data will be used to control the amplitude of an oscillator in Pure Data.

I have previously used an ultrasound sensor to control PD so the software interfacing is not a problem.

I have tried this method:
// CapSense.pde
// Paul Badger 2007

// Fun with capacitive sensing and some machine code - for the Arduino (or Wiring Boards).
// Note that the machine code is based on Arduino Board and will probably require some changes for Wiring Board
// This works with a high value (1-10M) resistor between an output pin and an input pin.
// When the output pin changes it changes the state of the input pin in a time constant determined by R * C
// where R is the resistor and C is the capacitance of the pin plus any capacitance present at the sensor.
// It is possible when using this setup to see some variation in capacitance when one's hand is 3 to 4 inches from the sensors
// Try experimenting with larger sensors. Lower values of R will probably yield higher reliability.
// Use 1 M resistor (or less maybe) for absolute touch to activate.
// With a 10 M resistor the sensor will start to respond 1-2 inches away

// Setup
// Connect a 10M resistor between pins 8 and 9 on the Arduino Board
// Connect a small piece of alluminum or copper foil to a short wire and also connect it to pin 9

// When using this in an installation or device it's going to be important to use shielded cable if the wire between the sensor is
// more than a few inches long, or it runs by anything that is not supposed to be sensed.
// Calibration is also probably going to be an issue.
// Instead of "hard wiring" threshold values - store the "non touched" values in a variable on startup - and then compare.
// If your sensed object is many feet from the Arduino Board you're probably going to be better off using the Quantum cap sensors.

// Machine code and Port stuff from a forum post by ARP

int  i;
unsigned int x, y;
float accum, fout, fval = .07;    // these are variables for a simple low-pass (smoothing) filter - fval of 1 = no filter - .001 = max filter

void setup() {

DDRB=B101;     // DDR is the pin direction register - governs inputs and outputs- 1's are outputs
// Arduino pin 8 output, pin 9 input, pin 10 output for "guard pin"
//  preceding line is equivalent to three lines below
//  pinMode(8, OUTPUT);     // output pin
//  pinMode(9, INPUT); // input pin
//  pinMode(10, OUTPUT);    // guard pin
digitalWrite(10, LOW);  //could also be HIGH - don't use this pin for changing output though

void loop() {
y = 0;   // clear out variables
x = 0;

for (i=0; i < 4 ; i++ ){ // do it four times to build up an average - not really neccessary but takes out some jitter

  // LOW-to-HIGH transition
  PORTB = PORTB | 1;   // Same as line below -  shows programmer chops but doesn't really buy any more speed
  // digitalWrite(8, HIGH);
  // output pin is PortB0 (Arduino 8), sensor pin is PortB1 (Arduinio 9)

  while ((PINB & B10) != B10 ) {   // while the sense pin is not high
    //  while (digitalRead(9) != 1)     // same as above port manipulation above - only 20 times slower!

  //  HIGH-to-LOW transition
  PORTB = PORTB & 0xFE;     // Same as line below - these shows programmer chops but doesn't really buy any more speed
  //digitalWrite(8, LOW);
  while((PINB & B10) != 0 ){ // while pin is not low  -- same as below only 20 times faster
    // while(digitalRead(9) != 0 ) // same as above port manipulation - only 20 times slower!


fout =  (fval * (float)x) + ((1-fval) * accum);  // Easy smoothing filter "fval" determines amount of new data in fout
accum = fout;

Serial.print((long)x, DEC);    // raw data - Low to High
Serial.print( "   ");
Serial.print((long)y, DEC);    // raw data - High to Low
Serial.print( "   ");
Serial.println( (long)fout, DEC); // Smoothed Low to High

I have had some success, however no matter how large resistor I use I am only getting usable results between 0 - 30mm from the sheet. I need to sense up to about 3m. Also I have many issues with erroneous readings.

I have seen circuits using 555 timers. I believe these function more like theremins. Would this be a more reliable method ? if so can anyone recommend a simple circuit I could use please ?

Any tips or suggestions for best way forward with this project ?

Many Thanks,

8  Using Arduino / Programming Questions / Re: SRF 05 Sonic Range finder to Rogue RMP3 via Arduino on: September 12, 2011, 03:30:13 am
The behavior you describe is precisely what I want to happen. It is exactly what happens when I use 'if else' commands to link to the mp3s on the card directly.

However, when ever I try to implement the *.mp3 method you have offered ( i.e. counting the files on the card and playing sequentially, irrelevant of actual file names) all that happens is - when someone goes in range I hear silence, and I notice the activity LED on the rogue mp3 flashing it short pulses about 3 times a second.

In normal operation the rogue has a solid lit activity LED to signify playback is taking place. So I am assuming the rmp3 is being triggered continuously. This is what happened to me at first when I was trying the *.mp3 code too...


9  Using Arduino / General Electronics / Re: electric fence batteries - possible use ? on: September 10, 2011, 01:28:04 pm
Many Thanks for all the help and information.

To update on my set up:

I am running an Arduino Uno with a Rogue Rmp3 shield attached and an Srf 04 sonic range-finder. The audio output from the Rmp3 is going into a little Kemo 12w audio amp, which is connected to a 8ohm/30 watt loudspeaker.

I need to power this lot for 10 days.

I have measured the Arduino/shield/sensor as needing 80mA 'at rest, and 110mA during playback ( the reading of the SD card is using this extra power I assume), this was tested with a 9v Battery plugged into the Arduino round power jack.

The audio amp is set at a low volume that is sufficient to playback speech at a reasonable level for listening at a 3m range. The amp/speaker are pulling 10mA 'at rest' and 80mA during playback. Surprisingly low, but the amp volume is way down.

I have worked this out over 10 days as requiring between 19.2AH and 26.4AH for the Arduino/shield/sensor, and between 2.4AH and 19.2AH for the amplifier.

I have purchased a Deep Cycle Leisure Battery which is 80AH capacity (so well over what I needed, but works out cheapest option compared to Sealed Lead Acid Deep Cycle Batts). I am also using a 12v solar charger.

I have heard that when fully charged these batteries can output over 14v, and possibly more with a solar panel attached, so to regulate the voltage I have run the power in to a  L78S12CV 12v regulator. At this point I have taken a power line off to my Amplifier. However, before putting the power into the Arduino I have added a Pololu Step-Up/Step-Down Voltage Regulator S8V3A (as suggested by CrossRoads in another post I think..) to take the voltage down to an Arduino Friendly 8v.

Hopefully this is a more efficient method of getting from 14+v down to 8v, than simply using a fixed (little heat generating) regulator....

Leisure Battery turning up tomorrow, so we will see if the theory works in practise.

I offer all this information in order to hear any views, alarm bells, tips.. etc and to possibly help any other beginners some info on car/leisure battery use..

Apologies for the length of the post, and any comments gratefully appreciated.


10  Using Arduino / General Electronics / Re: Dead Rmp3 Shield. Don't want to do it again.... on: September 10, 2011, 01:02:08 pm
Many Thanks for the suggestions.

MarkT was absolutely correct - I checked my arduino/Rmp3 and I did indeed have a loose solder point between the boards. I have re-soldered and it is now working again.

I shall try my best not to be so defeatist next time.  And I must offer appologies to the maker of the Rmp3 module. It obviously isn't made in such a way that the Vin would hurt it.

Its a great module that is doing exactly what I need, and with excellent sound quality.

11  Using Arduino / Programming Questions / Re: SRF 05 Sonic Range finder to Rogue RMP3 via Arduino on: September 10, 2011, 12:53:20 pm
I had a thorough check of my adrduino/rogue rmp3 and managed to find a loose solder point between the shield and the arduino,  I have re-soldered, and as if by magic, it all works again!! smiley

I shall have to try not to jump to the wrong conclusions so easily in future.

wildbill - I have tested the code you asked me to try and unfortunately it doesn't work. It seems to just play through all the track instantly when someone is in range, its the same behaviour I was getting when trying this technique.

Many Thanks for the help though. It would be great to be able to swap the mp3's on the card without reprogramming so if you can work out what going wrong I would love to know. Its definitely beyond me though at this point.

12  Using Arduino / General Electronics / Dead Rmp3 Shield. Don't want to do it again.... on: September 05, 2011, 05:08:01 am
I have managed to kill my Rmp3 shield.

I believe it was by running 9v in to the arduino input jack. I see from the Arduino site that the Vin pin becomes a Vout when you insert power to the round power jack.  Rmp3 can take 7v max before damage.

My questions are this :

If I had removed the header pins that connect the Vin and associated Gnd, and therefore just connected the Rmp3 to the regulated 5v pin and associated Gnd, would this have been totally safe ?

Seems surprising that someone would make a shield that could be damaged this easily. Perhaps it was the load i connected to the Vin connectors on the rogue (to power my  little 10 watt audio amp) ?

Any guidance much appreciated.

13  Using Arduino / Programming Questions / Re: SRF 05 Sonic Range finder to Rogue RMP3 via Arduino on: September 04, 2011, 05:06:37 pm
Yep. Just learnt an £85 lesson.

Just when I had it all running too. Sickening.

Going to get a new shield ASAP. I'll try your code then.

This isn't the end....


14  Using Arduino / Programming Questions / Re: SRF 05 Sonic Range finder to Rogue RMP3 via Arduino on: September 04, 2011, 04:31:28 pm
I would love to let you know if this works.. but I think I have fried my Rmps shield   smiley-sad

I connected a 9v batt to the input jack of the Arduino. All fine until I connected the Vin to my little audio amp.

I think by pulling the 9v through the shield for my amp it fried it. I thought it would be fine as the shield itself was obviously running on the 5v connection from the arduino... Says on the rogue robotics site never put more than 6v in..

Does that sound possible ?

Either way the Rmp3 is now not responding at all. Even to the simple playback sketch.

Anything else I can do to check it ?


15  Using Arduino / General Electronics / basic power input questions on: September 04, 2011, 05:53:35 am

2 quick questions :

1. If using a 12v battery, does it make any difference at all using the round 'centre-positive' jack input, or the Vin and ground pins ?

2. Will using an unregulated 12v lead acid battery, connected to the input power jack on a UNO be safe or not ?

Many Thanks

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