New answers tagged arduino
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Thats actually false, transistors are used as a switch. This lets you switch the cathode pins using a positive signal from an arduino such that each LED in the matrix can be individually controlled, allowing for the possibility of multiplexing. Simple.
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I would distinguish two types of broadcast:
Messages which are only sent to all nodes (and only those nodes) which are in direct range of the original transmitter
Messages which are sent to all nodes everywhere
A request to sending out the first type of broadcast will cause it to be transmitted the number of times specified by MT. The default is four ...
1
That could almost work. The thing to consider with DC/DC voltage converters is that they can change voltage but they can not create or destroy energy, thus the power demand from your energy source is the same as the power demand from the load, plus inefficiencies in the converter. Power is the product of voltage and current, so if your 12V motors draw at ...
2
In theory the idea is sound. However, those particular components won't work. The battery pack is rated for 5 watts. Your circuit uses 24 watts. The regulator has 90% efficiency, which means you actually require 27 watts, and the regulator is only rated for 15 watts. You'd also need to take leakage current into account, to make sure your battery ...
1
Your clock setup sounds very odd. If you have an external crystal already, you should not connect anything but that crystal to the XTAL pins.
There are some different cases of “not showing proper device ID”:
If it shows a sequence of plausible hex digits that just are not the device ID of the device you’re programming, search in avrdude.conf for what ...
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The Leonardo is a very nice board, but compatibility with shields can be a bit problematic, since the SPI pins are available exclusively from the ICSP header. There are also other subtle differences.
For a beginner, the Uno might be a better choice, except if you either know you’re not planning to buy shields, or if you have plans for fancy USB projects.
1
Cause: Why are you first converting the integer to a string:
String myString = String(sensorValue);
Only to try and print the integer itself on the next line:
Serial.write(sensorValue);
Solution: Change the second line to:
Serial.write(myString);
And/or check of @ConnorWolf's Serial.print(); solution works.
Another option is to:
#include ...
3
Assuming you're using Arduino-Tiny with the hardware serial port (and I think the soft-serial port too), I think the solution should be as simple as changing your Serial.write(intVar) to Serial.print(intVar)
As far as I can tell, the write function seems to be a lower-level thing, that only works on strings. What I think is happening is that you're passing ...
2
Select the milliamp range on the meter
Connect the red lead to the meter's milliamp socket
disconnect the power supply from the board
connect the ground of the supply connector to the ground of the board connector
Connect the red probe of the meter to the positive connector on the supply
Connect the black probe of the meter to the positive connector on the ...
1
Let me make a proper writeup of comments.
Start by looking at the product page at the Arduino website: Leonardo and Uno. A practical difference is that the Uno has a chip that can easily be replaced when you manage to blow up one or more pin drivers.
I just found that the differences are the Microcontroller, Digital I/O Pins, Analog Input Pins and SRAM. ...
1
The major difference between Uno and Leonardo is
- Leonardo has microcontroller ATmega32u4 which has support for the USB. Whereas the uno has ATmega328 which doesnt have the USB support on board.
So how this effects you and the cost
Since Leonardo has USB support onboard it doesnt require external microcontroller for USB connection. Whereas UNO requires ...
1
The Leonardo is 20% cheaper which might be important if you have almost no money. It has a few extra capabilities but lack of these are unlikely to hinder most beginners learning about Arduino and microprocessors. See Uno vs Leonardo
The Uno uses a replaceable microprocessor where the Leonardo uses a fixed surface mount device (SMD). If you damage the ...
1
To go portable you can use a portable Chrome Browser and install the extension to the site below.
-->codebender<--
Once the extension is install you can connect your Arduino and start building.
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your code is good for serial terminal, but not for GSM modem. It always take command in form of AT use AT+CMGR=1 to read the message.... send this command to modem and see the reply....
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Based on a quick scan of the manual, it appears that the only means of remote control of the speed/frequency is by the analog input, either 0 - 10 volts or 4 - 20 mA.
I don't see any mention of RS-485 or PWM control (except that PWM may be used to generate the 0 - 10 volt/4 - 20 mA signal).
Please note that I have not used this device - I just quickly ...
1
Assumption
Assuming you use this XBEE shield, when you check the circuit diagram, you'll notice that there is voltage regulator MC33269.
Cause of malfunction
Although MC33269 is an Low Drop regulator, it is spec'd for 1 ~ 1.35V dropout voltage. This means that if you supply 3.7V from your battery an extra 1 ~ 1.35V will be dropped for the XBEE, resulting ...
8
Most, if not all, input pins on AVR controllers are internally protected by clamping diodes. These diodes prevent that an input voltage can be higher than the supply voltage.
Why these internal diodes are there:
It is important to realize that when an input pin does rise above the supply voltage and these diodes weren't there, the chip might act as an ...
0
You can know, approximately, how fast the motor is turning by sensing the back-EMF of the motors without encoders. See How can I measure back-EMF to infer the speed of a DC motor?
Unfortunately this doesn't really tell you how much the robot has turned. Any error in your measurement will accumulate, and these errors will be significant. You will have errors ...
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Run a line from the 5V on the arduino to a small breadboard. Then run wires from the connected lines on the breadboard to your other components.
If I understood you right, you're more worried that there's only the one %v out line on the arduino, and you need to connect more than one device.
The other solution is to put a female wire on the ICSP pin 2 to the ...
1
The turtle bot has two geared motors. These can be turned ON and OFF and FORWARD and REVERSE. Without an encoder to measure the actual rotation you will need to basically guess (experiment with) the LENGTH OF TIME (DELAY) you activate the motors.
There are two ways you can turn a 90 degree angle.
(i) Turn ONE motor ON for a 'lazy' turn that will pivot ...
2
Drive the left and right motors in opposite directions.
If your design requirements constrain you to having no feedback, your best bet is to experiment with the time you turn on your motors. Note that this value can change based on things like the battery voltage and floor texture.
Since it has an Arduino, I'd suggest adding a nice gyroscope and ...
3
The names of the pins are clearly labeled on both the back of the board, and the datasheet.
PWR_IN is 5v to 15v, 12v preferred. The two regulators on the board provide the appropriate voltages from there.
DIMM IN is the '595's OE, Output Enable Pin
CLK IN is '595's SH_CP AND ST_CP Clock Pins
DATA IN is the '595's SI Serial Input Pin
CLK IN and DIMM IN ...
2
Assuming your supply isn't collapsing somehow, to me it's most likely that the CTR of the opto isn't sufficient to saturate Q1 and meet the pull-in voltage requirement of the relay:
The typical forward drop of an optoisolator photodiode is on the order of 1.5V
There's another LED in series with the path, dropping at least another 0.7V
The photodiode ...
1
Turns out I had the ATMega1284p running at "just" 1 MHz. Fusing it to run at 8 MHz made everything work just fine. Stable connection, reliable recognition of sensors, no data dropouts as far as I can see.
I'll try to get in contact with the mighty1284p and Arduino OneWire Library folks to discuss this, I guess their code either hardcodedly assumes the ...
0
I would suggest using separate wires for current return ("supply ground") and digital ground. Connect them at each end via small-value resistor. Suppose the wires in your cable are 0.5 ohms. If you didn't separate out your supply and digital ground, then you'd lose two volts (out of 24) in your cable. An 8% energy loss in the cable isn't wonderful, but ...
2
Not the way to do it, but a way...
The RF side is the difficult (as in most variable) part. One option would be to make use of the size of the luggage and embed a "frame antenna" into it - say, 7 turns of copper wire round the entire suitcase. (Convincing manufacturers to embed this into the lining doesn't matter at this stage!)
With the suitcases upright ...
1
For garbled data I think the problem might be with the way you are receiving the data in the Arduino. I had a similar question with Arduino/Android usb communication that can be found here.
You need to push serial data onto some sort of buffer before you can display or use the data. Since the rx/tx can be in somewhat random chunks and you cannot be certain ...
5
One important factor when working with stepper motors is hold torque. You can do some simple calculations based on your camera weight and platform radius to determine the torque due to gravity, and your hold torque should be a fair about larger than that or the motor will slip.
You'll also need stepper motor drivers in order to control the motors and ...
2
The other answers are just as valid as mine. I'm just offering yet another option.
Use a piezo buzzer. Something like what is in this picture:
When the piezo element is struck/stressed/etc it will produce a voltage spike that can be detected. They are commonly used in drum machine pads, elevator buttons, etc. They are fairly cheap, so you could ...
2
You could use resistive touch fabric, although I don't know how sensitive it is.
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You could use capacitive keys.
You didn't provide very much information about your system, so I can't give very detailed information on how to use this in your setup.
Some microcontrollers can control capacitive keys with a peripheral. There are also controllers available for these keys.
2
Your problem is that the programmer settings in your part entry (shown in your other question) override the programmer settings in the programmer entry.
Just lose these lines in the part entries:
mighty_opt8.upload.protocol=arduino
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here i post the working circuit(constructed myself using MSP430G2553 with internal oscillator & used 2XAA EVEREADY cell.when i decreased the voltage of the R8 below 0.8 and again increased to 0.9 or Vcc,controller freezes,then i reset the controller even you can use watchdog timer to avoid this problem)
...
0
"If it is serial would it not be possible for me to actually write an application for the Arduino that would issue commands over the FTDI connector for diagnostics purpose?"
Yes. You would need to implement a second UART or Serial port, as the hardware serial port on the Arduino is tied to the serial/usb connection. The original serial port talks to your ...
1
See Smart charging circuit for NiMH battery pack where the answer states
In such cases a very reasonable charging strategy is to terminate
charge at 1.45V per cell.
It is reasonable to believe he is referring to "at the cell".
It is worth noting that BQ2002PN is a FAST charge. You need to ensure it will not burn out your Cells. A good charger will ...
0
Is the FTDI connector just a serial interface or is it something different?
The documentation for your WiFi shield (daughterboard) will answer this.
FTDI is Future Technology Devices International - a company that makes integrated circuits commonly used to bidirectionally translate between low-voltage serial communications and USB "virtual serial ...
0
Look at my circuit it may be suitable for you:
https://www.circuitlab.com/circuit/dsyqc8/uc-switching-by-bjt/
BJTs Q1 and Q2 form an electronic switch. When SW1 is pressed the microcontroller will get +Vcc and in order to keep the uC powered the HOLD uC output should be made high. This works even at very low input voltage.
0
Yes, see here for the schematic of the sparkfun FTDI breakout.
As you can see on the far right, the FTDI connector has 6 signals, two of which are RX and TX. Those are the ones you would want to hook your Arduino's UART pins to. However, depending on the complexity of the diagnostics program (the computer program you are supposed to use to issue the ...
0
Why bother with a bipolar and relay. How about using a Pch connected from +5V input to the Vdd supply pin (arduino)? Use a switch to drive the gate from 5V (off) to gnd (on). The gate signal can be latched or toggled with a 5V logic device (eg. D type flip flop). Choose the PFET such that its Vt is -1 to -1.5V and an Rds-on (100mohms or less) that doesnt ...
0
There is a lot wrong with your circuit that other people have mentioned. I'm not going to go over those issues, but instead present you with an alternative.
When you say this:
I'm designing a circuit that will use a combination of switches and
resistors to allow a microcontroller to identify which switch was
pressed based on the voltage read and ...
0
There's a huge problem with your circuit: You have the relay in series with the emitter, which means that the relay can only get whatever voltage is on the base, minus the 0.6V or so B-E drop of the transistor.
For what you are trying to do, you need to put the relay in the transistor's collector circuit, and use a second transistor driven by the Arduino to ...
3
Yes; best case the hFe of a BJT will be 100 or so, which means your 0.017 mA will turn into 1.7 mA, which is not enough to power the relay coil.
There's another problem, too: The current out of an Arduino will not be sufficient to drive the coil of a relay, as the typical spec is 25 mA per pin out, and typical relays use 35-100 mA of current for their ...
0
I have no experience with this particular type of application but my guess would be that it all depends on your available RAM and what sort of features the codec has for directing it to the buffered data in RAM. So when you scroll forward your code would tell the codec to skip some buffers in RAM. But meanwhile your code would have to anticipate what buffers ...
0
Only the XBee products with "ZB" in the name provide "Interoperability with ZigBee devices from other vendors"
As I understand it:
the products with "ZB" in the name have the "Zigbee Feature Set" included in the device firmware. The code enables the device to use the Zigbee protocols needed to interoperate with Zigbee devices from other manufacturers.
...
2
Please see Chrontel's products at www.chrontel.com:
CH7035 - TTL to HDMI output.
CH7026 - TTL to CVBS.
CH7033 - TTL to VGA and HDMI.
CH7034 - TTL to VGA.
CH7322 - HDMI CEC.
Their TTL input supports RGB 8-8-8. 5-6-5, YCrCb 4:2:2, ITU656, etc.
I think the Arduino can use their MCU interface to write graphics data to their frame buffer directly. On-chip ...
1
The choice really makes little difference when you are using the Arduino libraries. You should see the same type of performance.
As for the i2c pullup resistors, the BMP085 board you link to has pullups already on the board, connected to a closed solder jumper. Those same pullups should be enough for both sensors, so you wouldn't need to add more.
But ...
1
So far as I know, many GPS receivers communicate with other devices using NMEA
I wasn't aware that there was a variant of the old Hayes V21 voice-frequency modem AT command set for GPS.
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Many MCUs won't handle the current for seven segments unless a transistor is used. You might be OK with the AVR (40 mA maximum per output, IIRC), but you need to check it, and the total current.
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You have received some excellent answers on intercepting the data in the digital domain but it may also be worth considering using the analog signals presented at pins 30 and 31 on the ICL7136. An adantage to this is only having a pair of lines to connect per device and probably a simpler software interface. Some things you'd need to check are:
Make sure ...
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