Show Posts
Pages: [1] 2 3 ... 78
1  Using Arduino / Programming Questions / Re: including Multiple Libraries for one Sketch on: July 29, 2014, 11:33:16 am
Yes.  They should load even if they don't play well together (like Servo and IR libraries that use the same timer).
2  Using Arduino / Sensors / Re: cycle through analog values on 4digit 7 Segment display on: July 29, 2014, 10:03:18 am
moisture1 = analogRead(A0);
unsigned long currentMillis = millis();
display.PrintOutput();  //this executes every time through loop().  Is that what you want?
if(currentMillis - previousMillis > interval) {
  previousMillis = currentMillis;
  display.PrintOutput();
  display.NewNum(moisture1,(byte) 4);
  Serial.println("moisture1: ");Serial.println(moisture1);}
3  Using Arduino / General Electronics / Re: Breadboard Replacement For Relay Omron G5V-1-DC5 on: July 29, 2014, 09:54:10 am
I don't know of a specific MOSFET but it should be easy enough to find.  Look for a logic level MOSFET with low Rds (on resistance).
A proper MOSFET will be much more efficient because the current to turn it on is negligible compared to the 30 mA to hold the relay closed.  You can also use PWM to control motor speed with the MOSFET (not feasible with the relay).
4  Using Arduino / Programming Questions / Re: Controlling a small stepper motor with the millis() command on: July 29, 2014, 09:47:39 am
If currentMillis - previousMillis is 320 what happens?  It is greater than 100 so that if fires, it is also greater than 200 so that if fires, too.  And so on.  I think that if you reverse the order of the checks it may work. 

if(currentMillis - previousMillis > theEnd)
else if(currentMillis - previousMillis > picLow)
etc.
5  Using Arduino / Programming Questions / Re: including Multiple Libraries for one Sketch on: July 29, 2014, 09:19:59 am
I would be helpful if you could show the error messages.  Most likely is that a library is not installed properly or misnamed.
6  Using Arduino / Sensors / Re: K-Type element for up to 1200° on: July 29, 2014, 08:51:56 am
Look at Omega.com.  They have thermocouples for everything.  Not the cheapest but you can probably find the perfect sensor.
7  Using Arduino / General Electronics / Re: Breadboard Replacement For Relay Omron G5V-1-DC5 on: July 29, 2014, 08:37:50 am
Do you use both no and nc contacts?  Can you use MOSFETs instead (if switching DC)?
8  Using Arduino / General Electronics / Re: Serial Issue on: July 28, 2014, 07:42:35 am
Connecting Tx to Tx is connecting 2 outputs together.  Not good.  For serial communication you need to connect Tx to Rx.  Transmit output to receive input.
9  Using Arduino / Programming Questions / Re: led control pannel on: July 26, 2014, 07:04:00 pm
A byte is 8 bits and can hold values from 0 to 255.  An int is 16 bits and can hold value from -32768 to 32767.  Unsigned int holds 0 to 65535.
10  Using Arduino / Programming Questions / Re: led control pannel on: July 26, 2014, 04:51:00 pm
You have an errant right curly bracket after patternIndex = 3.  It closes loop() so pattern index is out of scope in the part where it is used.
11  Using Arduino / General Electronics / Re: Setting up 'switch' on: July 25, 2014, 12:57:15 pm
The  voltage, with the to pin set to INPUT_PULLUP, comes from an internal Vcc connection to the internal pullup resistor.  virtually no current flows into the input with the switch open.  When the switch closes the input is pulled to ground and current will flow from the internal Vcc to ground through the resistor (Vcc/pullup value ohms). 
12  Using Arduino / LEDs and Multiplexing / Re: Trying to make simple LED Light for Aquarium on: July 25, 2014, 09:33:16 am
Running LEDs without a resistor is not a good idea.  It may work, short term, but a temperature change could allow more current flow and poof goes the output or LED(s).  You need to observe the current limits of the chip.  20mA (to be safe) for each pin, 150mA for each port and 400mA total for the chip.  If you are near any of those limits you need to go with transistors/MOSFETs to drive the LEDs.  With as many LEDs as you want to use I would use transistors.
13  Using Arduino / Networking, Protocols, and Devices / Re: Set Data rate on NRF24l01 on: July 24, 2014, 04:01:52 pm
I think so.  It has been a while since I messed with the rf24.
14  Using Arduino / Networking, Protocols, and Devices / Re: Set Data rate on NRF24l01 on: July 24, 2014, 03:50:11 pm
The payload is the data you want to send or receive.   I think that, unless you are using dynamic payloads, the payload size must be set to the same value in both ends.
15  Using Arduino / General Electronics / Re: Setting up 'switch' on: July 24, 2014, 01:00:16 pm
When the internal pullup is enabled there is a built in resistor switched in between Vcc and the input pin.  That way the pin is tied to Vcc and is in a known state with the switch open.  Then pin can then be safely pulled to ground by the switch closure and the internal resistor will allow only a small current to flow through the switch to ground.
Pages: [1] 2 3 ... 78