A message from our CEO about the future of Stack Overflow and Stack Exchange. Read now.

Tag Info

0

Yes, your choice is right. You can manage more inputs and outputs with MC14051B, MC14052B, MC14053B. Link of the data-sheet is- https://www.onsemi.com/pub/Collateral/MC14051B-D.PDF To increase output voltage- To decrease input voltage use resistors according to the voltage divider rule.

0

The pads on the back of the arduino are designed to have a double row vertical surface mount terminal strip soldered to it. From there you can make a 'dupont' cable assembly to connect it to the debugger. Alternatively a number of adaptor boards exist to connect to common debuggers. Or create a pcb that can plug into the terminal strip and provides a ...

0

A voltmeter measures the potential difference across two points in an electric circuit. Meaning that you need to connect the voltmeter wires to the positive (+) and negative (-) terminals to what you want to measure. So, you connect a voltmeter in parallel to your power supply. In your case the voltmeter part measures the difference across the thin black and ...

0

You need to specify the conducted emissions, on both input and output voltages. You also need significant input L+C filters and output filters. You need a Ground Plane under this region. Without these methods, you can pick "the best switchReg" and still fail.

1

You can use a transistor as a heater, however you would be better off to add at least one resistor to control the collector current. Given that, you might want to use the resistor itself as the heater and drive the BJT or MOSFET fully on to minimize the power dissipation in the switching device. Dale makes suitable chassis-mount wire-wound resistors, and ...

0

The current trough a transistor is poorly controlled by the base current. Is is better controlled by the base emitter voltage. However, that formula also calls for millivolt control ( as well as knowledge of the temperature, which you know). Given these drawbacks, the very best solution may be to use some sort of current sensing...like an emitter resistor. ...

0

I tried using a Raspberry Pi with 14 x L298N Dual H-Bridge Driver Modules to run the electromagnets and it usually works, but there's a lot of wiring involved with the H-Bridge modules, making fault-finding tricky, and I've had a few fail on me already. If you used lots of small pcb modules with L298's on them then I guess current pulses in ground wires are ...

0

You must generally use contacts and housings from the same manufacturer and connector series. Good distributors will usually specify what contacts are used with which housing.

0

Another possibility would be to use the DMOS power shift registers in TI's TPIC series. This shows active pullups on each output. You could use resistors but that would come with other issues. simulate this circuit – Schematic created using CircuitLab 7 is the minimum number of shift registers required, but it might be better to use 8 and then each ...

1

You screwed up. There is no common name that I know of, at least not one used by a reputable manufacturer. The description you need is a crimp terminal that mates with 0.635mm/0.025" square post headers. The crimp terminal on the left clearly does not mate with a square post. One example is the from Molex which is the "SL Series".

0

Don't dismiss the possibility of using relays. simulate this circuit – Schematic created using CircuitLab Figure 1. Figure 1a is, in effect a H-bridge. The polarity on the coil is reversed when the relay is energised. This suffers a major disadvantage that the coils, which are probably intended to be impulsed, are powered continuously and may burn ...

0

Okay, so thanks to @Maple, i got it working! The wiring was almost correct, one thing i had to add was another connection from the ADS's ground to its A3 Pin and configure the register just like @Maple suggested.

0

It can be done with a diode matrix in a similar fashion to what is done with ferrite core memories as they also require bipolar operation. Although core memories extend the matrix drive by exploiting the 1/2 current drive with coincidence selection of the X and Y axes this could not be exploited here. Selected coils would receive full drive, unselected ...

0

You have 28 bipolar electromagnets so it's difficult to use a matrix arrangement unless they will reliably not flip with 1/2 voltage. Diode isolation won't work. I suppose you could consider putting a bipolar TVS in series with each coil, and boosting the drive voltage (already pretty high for the driver though). Targeted coil sees +/-(Vs - Vz), non-targeted ...

0

Adding as answer, because can't comment. To answer briefly, yes you can. Please refer to Anindo Ghosh's Answer on how to do so. Please Note however that for the Arduino Nano, pins A6 and A7 are analog only and cannot be used in the digital mode.

0

It is just a matter of adding more regulators matched to the same voltage to share the load. The highest voltage regulator hogs more current so they just have to be matched within 1%. A trimpot with an adjustable regulator with fixed R limits to fine tune 5V to achieve thermally matched (shared current * Voltage drop) regulators is a good way to to it. ...

1

Just connect the system out to the Arduino Pro (BATT connector), as shown in your picture. The Arduino Pro uses 3.3V for the ATmega328 MCU, but the board (the Arduino itself) has an on-board regulator which can accept up to 12V DC. Check out the specs on the item at Sparkfun:

1

simulate this circuit – Schematic created using CircuitLab Just replace ground with the other phase.

0

I need to replace the left hand side of the schematic with an Arduino or similar This statement does not make any sense. The left side of the schematics is just an interface, you do not "replace" it, you connect "Arduino or similar" board to it. After making sure that voltage levels are compatible, of course. But that is a simple task of choosing correct ...

1

i use 3 resistors to make it a quarter-bridge I don't see your wiring in the schematics, but if what you are doing is what I think, then you basically killing the performance of the strain gauge. Not a good idea. You need to switch all four lines. Also, i read something about multiplexers, but they don‘t seem to be exactly what i‘m looking for You ...

0

You could use 100+ sets of 2 DPDT relays, with 3 signals+power+Gnd from the Arduino to shift data into TPIC6B595 shift registers to sink the relay's coil current, one pair at a time. The ADC is then connected to one H-bridge at a time. You can use 5V relays, telecom relays need 31mA or less to energize them from 5V. Examples: https://www.digikey.com/...

1

If I understand correctly: You would want 4 on/off switches in parallel in front of each signal line from the strain guage. Each of the switches would be wired to one of the four quadrants of the wheatstone bridge. Only one (or none) of the 4 switches would ever be on. Repeat this for all strain gauges. Then you would just have to be careful what to ...

0

try this circuit. It worked for me after 3 weeks of testing and burning out components. It works fine from 4.1V to 23.5V. You need a 10K trimpot (DS1804) and an op amp (LM311). I tried with other op amps, but without success. Good luck.

2

Unlike other devices in ADS111x series, ADS1115 includes source MUX that selects which of the input channels will be used as inputs for differential amplifier. Since you are measuring shunt voltage referenced to the ground, you have to select GND as one of those inputs. See "9.3.1 Multiplexer" diagram in the datasheet. This is done by setting bits 14:12 in ...

0

The Arduino Uno has ADC inputs however, you cannot plug 12V straight in, you'll have to divide the monitored voltage to the acceptable ADC range then scale back in your code to retrieve the actual voltage. The ADC range is 0-5V so, after fully charging your batteries, measure the UPS voltage and size the divider resistors values so the voltage you are ...

0

The Atmega used on the Arduino has an ADC on board. Use it to measure the battery voltage and when the voltage falls below a threshold use a digital output to open a relay to cut off the load from the battery. Now you can start designing your circuit. If you have more detailed questions during that process feel free to come back here.

1

the TX line from the Arduino runs to the RX of the SA818 If you look closely at the block diagram for the SA818 (below)... ... you will see that the RX line is an output and this therefore means that you are connecting your UART output to the SA818 RX output. Even though you are doing this via resistor it doesn't make any sense at all. Of course, I can't ...

0

Without $R_L$, a much larger voltage may appear across the transistor, from collector to emitter. It is incorrect to say that the voltage at the collector is the same as the voltage at the base. The voltage at the collector will change as needed to control the current. If the base voltage is about 2.5V then the emitter voltage will be about 1.1V. If the ...

0

If using digital LEDs such as WS2812 aka "Neopixels", a standard Arduino Uno can control up to 600 RGB pixels, without having to multiplex anything :) The only limitation here is the RAM of the board. A board with more RAM, such as an Arduino Mega that has 8kb of RAM can control up to 2400 pixels, when compared to an Uno which has only 2kb of RAM. You can ...

2

Firstly, be cautious not to connect the two touch terminals together, it may damage the transistor. The circuit can be manipulated in various ways to sense for a finger touch at the touch terminal. One of the ways can be to take a wire from the collector of the transistor and give it to the Arduino(make sure to use a lower voltage battery). When the ...

1

After a chat with OP to debug connections, here is how the problem was (somewhat) solved: HC-05 should be connected: VCC and GND to the Arduino's VCC and Ground respectively TX of the Arduino (the designated TX pin; the second argument of the SoftwareSerial declaration) goes into a resistive divider of 1k:2k, and the output goes into the HC-05's RX pin RX ...

0

1) Yes, you will need a separate ground connection. It looks like the TB6600 has isolated inputs, meaning your Arduino will be floating relative to the relays. Otherwise the 12V powering your relays won't have a current return path. 2) Using a computer power supply won't do any damage, and if you're using the USB for communication as well as power then it ...

0

For maximum accuracy, you want 5 V output from the current-sense amplifier when 30 A is flowing through the shunt/sense resistor. Since the voltage gain of the device across the shunt resistor is 20 V/V, then the maximum required resistor value would be: R = 5V / 20V/V / 30A = 8.33 milliohm. You can see a close-by example in the second-to-last row of Table ...

2

Your original question was confusing. I have edited your question, hopefully to make it clear. So what you are building is a transistor inverting switch, and you want to turn the LED (D2) on and off by shorting it via the transistor, and the transistor is controlled by an output pin of an Arduino or Raspberry Pi. There are several potential problems, Make ...

0

You've got the resistors in the cathode circuit. The resistors should go the other side of the LEDs in the anode circuit. At the moment you are driving each column of 8 leds with a shared dropper resistor and forcing all 8 to have the same forward voltage drop. This causes current hogging and can blow some of the LEDs.

0

The simplest thing to try would be to add a 10k ohm resistor between the IO pin and ground in your original circuit. This should quickly drain the remaining charge out of the IO pin after Q1 turns off.

1

You made a few errors in your code: ESC.attach(9,100,2000); should be ESC.attach(9,1000,2000);, so, 1000 instead of 100. and potValue = map(potValue, 0, 1023, 1000, 2000); should be potValue = map(potValue, 0, 1023, 0, 180); because the next line, the command writeMicroseconds(angle) only accepts a value to write to the servo, from 0 to 180 Have a look ...

4

A pull down resistor is not to prevent a short circuit. Your diagram is quite minimal, but a pull down (or up) resistor is used in the following situations: You connect something to an input pin. When the switch is open (or no closed circuit,) the input pin will get values between 0 (GND) and e.g. 5 (VCC) volts and anything in between. With a pull down or ...

4

Is it really to avoid shorting between the 5v and ground?? So if there is a LED (load) in the circuit when the button is pressed do we really need the pull-down resistor? A pull-down or pull-up resistor is used to give a floating pin a defined potential. Sometimes it's also used as driving source for serial communications as usually controller pins are ...

0

On a contemporary microprocessor you will most likely write a graphical user interface that does your job. The GUI has its own event loop(s) where things like mouse clicks, redraws etc. are processed. Most of your functionality will be located inside of an event handler that is delegated to by the main event loop. Thus, if inside such an event handler you ...

1

Depends on whether your ATmega system is running off of AC wall power or small batteries. Running off of AC (via a wall wart power supply) the power consumed by 100% CPU utilizing spin loop is below the noise floor of the variation in your utility bill. Heat dissipation most likely too small to require a heat sink or fan, unless in a super insulated ...

3

Am I right in thinking that the ATmega is in fact running at 100%, and that because it is so low powered it doesn't cause any obvious heat problems? Yes, it normally runs at 100% all the time, but is so low powered that it doesn't heat up significantly. On a desktop / laptop with an Intel i7 CPU etc if I ran a similar infinite loop (with nothing to ...

2

A "gate driver" integrated circuit may be just the thing here. They're designed to take logic inputs to higher voltage swings. Another possibility is a high voltage analog switch IC. I've used the DG403 as a CCD gate driver and Cockroft-Walton HV exciter in several space missions. There are too many choices for me to venture one for your application ツ

0

The 74HC595 powered at 4.5 volts when driving a load current of 6 mA will produce an output voltage of somewhat less than 4.5 volts; more like 4.3 volts (Table 7.5 in the electrical characteristics). This is a typical value and it may be as low as 3.98 volts. You are trying to drive up to 8 LEDs simultaneously from one row output. You might be aiming for 10 ...

0

Let's analyze the problem which is all due to wrong drivers for proper impedance. (mis-wiring and failed IC wirebonds maybe from over heating) The 74HCxx driver resistance is too high. For proof of concept increase all 220 Ohm resistors to say 0.5~1k Ohm and tolerate low illuminant intensity. They give driver specs with -10% Vcc tolerance like 4.5V and ...

0

Lets analyze what's going on here. The code is implementing a multiplexing scheme, which is to say at any given moment, only one row of LEDs is being "addressed" (i.e. 128 >> i, the row addressed by the i-th bit). I'd advise you to rename the variable called SHIFT to CLOCK as that is what most people will expect it to be called. Usually the variable ...

8

Another approach : a Schottky diode from Q1 base to collector; or possibly on both transistors (with the appropriate orientation). As each transistor starts to enter saturation, Vc falls below Vb and the Schottky diode becomes forward biased. This drains further base current preventing the transistor entering full saturation, which is a major cause of ...

3

The signal is in frequency range of 10 to 4000 Hz. A precision of 2 to 5 nV would be sufficient. Uh, good luck with that. Thermal noise power at room temperature is $$N = k_B T B\text,$$ with $k_B$ being the Boltzmann constant, $T$ absolute temperature, and $B$ bandwidth. To observe your 4 kHz signal, you'll need a 4 kHz bandwidth (=9 dBHz) (...

12

Why is this seemingly ok on a microcontroller but not usually wanted on a microprocessor? It is also unwanted on a microcontroller for the same reason: it wastes power. Am I right in thinking that the ATmega is in fact running at 100% Correct. and that because it is so low powered it doesn't cause any obvious heat problems? Correct. However, if you ...

8

On a microcontroller (more specifically, on an Arduino Uno board using the ATmega 328P microcontroller) I would normally use an infinite loop to check for inputs etc (in Arduino land, this is normally the loop() function). If I leave this function blank however, it doesn't cause any problems. Classical programming pattern, having a main loop… On a ...

Top 50 recent answers are included