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Questions tagged [floating-pin]

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I've read general advice for unused pins is to tie on to some known potential (GND, 3.3V), but no where in any datasheet (of the specific IC, and similar parts from Winbond) it covers what to do with ...
Bikay's user avatar
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I have an FTDI breakout board running over USB. I am using a SRX882 433 MHz RF receiver. Using a scope I can see the receiver sending a 3.2 V output on it's data line when it's receiving. The input ...
mr0mega's user avatar
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2 votes
2 answers
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I’m using an ESP32-S3 to communicate with a 5V-only LCD module with an i8080 parallel bus interface. To shift the levels, I’m using the SN74LVC8T245 bidirectional level shifter. This means I can both ...
Emil Sahlén's user avatar
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1 answer
372 views

I am receiving "contains floating input pins" errors on my altium designer schematic (among other issues) despite the wires being correctly connected, and each port and respective component ...
YouGotDecked's user avatar
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2 answers
144 views

How do deal with Input pins, which not in use. Have seen many examples, where they kept floating, but I don't like personally when an high-Z inputs kept floating in the design in some IC which I could ...
Pinus's user avatar
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7 votes
1 answer
409 views

In one of our projects, we use an STM32L071 MCU in an LQFP48 package. It exposes GPIO port pins PA0 to PA15, PB0 to PB15 and PC13 to PC15 on the pins of the package. The LQFP48 package doesn't expose ...
NZD's user avatar
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1 answer
127 views

I need a simple circuit that during power on fixes a pin of an IC to GND and after a while leaves this pin floating. Another circuit should be the same, but fixing another pin to -VEE (-30 V) and then ...
mtx4's user avatar
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2 votes
1 answer
342 views

On MCP34xx devices datasheet on page 2 it is written: The I2 C address bits for the MCP3427 and MCP3428 are selected by using two external I 2 C address selection pins (Adr0 and Adr1). The user can ...
php_nub_qq's user avatar
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1 answer
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I have been reading the datasheet of RV-3028-C7. Everytime it talks about a pin that might be unused in a certain scenario (should be logic low), it instructs to connect the pin to ground through a ...
Mora's user avatar
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0 answers
179 views

This circuit has been implemented on my PCB. However, when I test this circuit (without the DRV135UA), it surprised me that the PLL works except Pin 14 of NE564D (V_PLL). At Pin 14, I did not measure ...
Kwok's user avatar
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4 answers
2k views

I'm designing a circuit using the MAX22203 motor driver and it has a few open drain outputs to indicate current throttling. In my design I don't need to read these outputs, so my question is what ...
csiz's user avatar
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2 votes
3 answers
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I am having this microcontroller - S32K142 64 pin 5V core voltage I have a few pins which I don't want to use. While checking the datasheet of the Microcontroller, I couldn't find any information ...
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I'm trying to integrate an ESP32-PICO-KIT/V4.1. into a small project. The documentation for the PICO power supply says this: There are three mutually exclusive ways to provide power to the board: ...
par's user avatar
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3 answers
601 views

I have to choose a mcu for a project and I only need 4 I/O pins. However, microcontrollers with higher computational power usually have many pins. Are there any disadvantages using a high pin count ...
pedrocklein's user avatar
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2 answers
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I have an Arduino project that includes three sensors a EC, PH and PPM sensor. The problem is that when you read a sensor the other two sensors affect the reading of the current sensor due to the ...
Edwin Martin's user avatar
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3 answers
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Ever since I connected a button to an Arduino for the first time, I've wondered how does the resistor prevent floating input from happening? I've read several answers to similar questions, seen videos ...
Magnar Kleppe's user avatar
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1 answer
294 views

I'm designing an audio mixer and currently i'm working on a cue section. The whole point is that i have 2 or more channels and want to mix them in summing mixer. You can turn off the channels you don'...
cubix's user avatar
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1 vote
1 answer
771 views

My concern is that pins are connected between DB25 and TXS0108E, but are not connected between TXS0108E and the Header 5x2. There is only the tracks between TXS0108 and the Header 5x2, but there is no ...
Daniel's user avatar
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1 answer
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I'm using this 4-channel ADC: MCP3422 -> Datasheet I only need to use 3 of the available 4 input channels in total. Normally I would add footprints for pulldown resistors for example in case a ...
H123321's user avatar
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1 answer
427 views

I use an analog input from an Arduino to read the value from a piezo plugged in parallel with a 1M ohm resistor. I followed this tutorial from Arduino: https://www.arduino.cc/en/Tutorial/Knock Here ...
Christophe Gudlake's user avatar
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1 vote
5 answers
5k views

I would like to measure that voltage of a floating GPIO on a Raspberry Pi 3. When I use a multi meter or an oscilloscope it looks like the pin is pulled to ground and shows 0. Another way of asking ...
Greg Vercellotti's user avatar
  • 11
3 votes
1 answer
219 views

I am working on a video scaler chip which has multiple inputs (i.e HDMI, DP, VGA) but I only want to use the VGA input. (Choosing another chip with only one input is not an option). The friendly ...
cheweyjunior's user avatar
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0 answers
945 views

I have a microcontroller that uses 4 GPIO pins as "bootstrap pins". The state of these pins (high/low) at boot time will determine important features of the microcontroller, such as output voltage to ...
Shanee Vanstone's user avatar
  • 129
0 votes
2 answers
154 views

I have an application where I need to make a ADC input pin (0-1V) float controlled by GPIO (any connect it in other cases to its input obviously). I was considering a transistor in-line with the ADC ...
ARF's user avatar
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0 votes
2 answers
3k views

I am relatively new with Arduino and did a little bit of research prior to this post. But I am trying to sense when I have voltage coming from an AC/DC converter (12Vdc) so I can switch from my ...
Mason's user avatar
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1 vote
0 answers
232 views

I have a momentary push switch connected to my mbed microcontroller. The switch is used to trigger an interrupt which changes a setting on the device. At the moment the button works around 70% of the ...
DonnellyOverflow's user avatar
  • 258
1 vote
2 answers
1k views

I'm currently having a strange issue with what I think is a 'floating' signal. The setup: I have a bank of inputs (which are connected to a resistor and LED acting as a pull-down) connected to inputs ...
Matthew Shaile's user avatar
  • 13
2 votes
1 answer
252 views

http://forums.benheck.com/viewtopic.php?f=18&t=38664 In the link, there is a thread discussing replacing gen 1&2 Pokemon cart sram ICs with fram equivalents. The only differences between old ...
Alexander M's user avatar
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1 answer
77 views

I'm trying to figure out what happens to a 30 Volt supply when it is attached to a circuit of resistors which are not grounded. I know that eventually (steady state) the voltage of the circuit should ...
turbonate's user avatar
  • 3
-1 votes
1 answer
99 views

Why do some cmos Imaging sensors have 48 pins and others 36 and some 34...e.c.t? I'm new to these sensors and I don't really understand the connectivity differences.
Simon's user avatar
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3 votes
1 answer
5k views

I am building a simple inverting operational amplifier circuit where I am using a chip with dual amplifier. I am only using one of the two amplifiers. What should I do to the unused amplifier's input ...
dr3patel's user avatar
  • 1,672
1 vote
1 answer
192 views

I'm designing a relay-driver board with 15 double throw relays. I'm using shift registers to save IO-pins on the CPU. The shift registers feed into darlington ST ULN2003A transistor arrays: http://...
avl_sweden's user avatar
  • 1,024
1 vote
3 answers
509 views

I'm working on plugin for simulation software (digital IC only). For example there is 8 bit bus. User wants to read it's value. On plugin side I check each pin's state. It can be 1, 0 or undefined. At ...
pugnator's user avatar
  • 166
4 votes
1 answer
623 views

I'm curious about a strange effect I observed. I was designing a device, which sleeps most of the time and can be woken up by a loud sound signal, like an opening door, a clap, etc. The relevant ...
anrieff's user avatar
  • 5,585
1 vote
1 answer
1k views

I'm using a FXLS8471Q accelerometer for a project using the SPI interface. The chip uses the same pins for SPI and I2C. To detect which interface the user desires, the chip samples the SA0 pin on ...
Dan Laks's user avatar
  • 8,674
10 votes
2 answers
4k views

I am working on an application using ATmega328p atmel microcontroller. I started with the 28 PDIP version, but now I want to use the 32 TQFP, which I noticed has 2 extra inputs after compiling my ...
esal26's user avatar
  • 123
0 votes
1 answer
131 views

I am building an eeprom programmer for the 28C64A (dip package) with my old basic stamp ii "homework" board (lost my arduino in the move). I have the first four address and data pins, as well as W E ...
OrangeCalx01's user avatar
  • 299
1 vote
4 answers
1k views

simulate this circuit – Schematic created using CircuitLab I use D1 to visually indicate the active transistor. However, gate pin acts as if it were floating. What is wrong with my gate-...
FlegmatoidZoid's user avatar
  • 509
-1 votes
2 answers
1k views

Is it possible to make the output of this circuit 0V, when the input is floating as shown in the picture . I tried adding a pulldown resistor to the input, but it only worked at a very low value(100 ...
Ollusaurus's user avatar
  • 55
12 votes
2 answers
41k views

I have set up my Arduino UNO with 4 input wires, they connect to the port 10, 11, 12, 13, they are connected to my breadboard with nothing on it but the wire. My code would simply be: ...
Guilherme Garcia da Rosa's user avatar
  • 309
6 votes
2 answers
733 views

I've been looking at my scope's power supply board and I noticed that R7731A "Burst Triple Mode PWM Flyback Controller" in DIP has two NC pins which are not connected to absolutely anything. They've ...
AndrejaKo's user avatar
  • 24k
1 vote
3 answers
3k views

From my recent introduction to pull-up/pull-down resistors, I understand that an input with a pull-down will stay low instead of floating. Since the pull-down resistor leads to ground, couldn't I ...
RocketLauncher's user avatar
  • 43
1 vote
2 answers
416 views

RF/IF encoder/decoder IC's such as this one, will accept the address-pin in one of 3 states: Floating High Low As per this excellent answer, I believe "Floating" input can assume either High or Low ...
bdutta74's user avatar
  • 3,544
21 votes
7 answers
6k views

I just read through question AVR Random Number Generator and encountered a number of ways to generate random seeds in an AVR: Use a special-purpose "Secure AVR" Use an internal temperature sensor Read ...
Vorac's user avatar
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