Questions tagged [pullup]
A Pullup Resistor brings a line up to a voltage (Typically VCC), while allowing the line to be pulled low.
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I2C bus problems when using two distance sensors in Arduino
I have built a prototype to measure two distances using two time of fligth (TOF) sensors based on VL53L0X IC (from this manufacturer) which are connected to an Arduino board. Due to the environment ...
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Push-pull along with pull-up
A FPGA I/O is connected to the OE# of a transceiver and I want to ensure that OE# is high (>=2V) when the system powers up and until the FPGA is configured. The system is battery powered and the ...
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Art of electronics - figure 2.10 [duplicate]
Why shouldn't the resistance of R3 be less than 100 ohms? (See note 12 mentioned at the bottom of the image.)
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Selecting biasing resistor values for MAX3485
I created a schematic for the MAX3485 with the ESP32, but I have a question about the selection of biasing resistor(R39,R40) values. Some people use 4.7k, 10k, and 20k ohm resistors, but I'm unsure ...
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USB-C pull-up resistors set to 3A, but phone charges slowly
I am building a custom charging panel that will sit behind our couch. It has four DIY USB-C cables that can be pulled out to charge phones. Under the panel, they connect to a 5V power supply rated for ...
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MeanWell DRC-40A "AC OK" pins to Arduino nano ESP32
I would like to detect if my DRC-40A is supplied by mains (220v AC) with an arduino nano esp32.
I thinked in this two options:
Is it better A o B?
I also want to keep safe the Arduino's 3.3V.
The ...
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Do I need to keep a pull up resistor in SPI CS line of AD5941
I am designing a stand alone board which contains only AD5941. AD5941 contains SPI interface. STM32 board is used for communicating with AD5941.
Cable assembly will go from STM32 board to SPI ...
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Pull up Resistors value for Multiple devices with ESp32
I am designing a PCB board with an ESP32 and multiple I2C devices on the same I2C line.
One I2C device is an RTC (Real-Time Clock) chip, which is included in my board design. I will take the chip and ...
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When would we like to use a resistor here?
In Xilinx's 7 Series FPGAs Configuration User Guide (UG470), they say
M[2:0] determine the configuration mode. Connect each
mode pin either directly, or via a ≤1 kΩ resistor, to VCCO_0 or GND.
Adding ...
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Why would you put a pullup resistor on the output of a TTL compatible IC?
I am building a square wave generator with a ne555. The datasheet in section 6.3.2 Astable Operations has an example circuit that is essentially the same as my practice circuit but with a 1k pullup ...
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Why do my pull-up resistors not work? [closed]
I am new to electronics and I am trying to build RGB LED which can be controlled with buttons. Each button toggles red, green and blue value respectively. I am stuck with buttons, I am trying to make ...
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Sensor power sequencing
I am trying to make a power up sequence for a sensor that requires 3.3V, 5V and 10V. 5V and 10V power should be applied after 3.3V.
My PCB is powered by 12V, and I use STM32L4R5, connected to the EN ...
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Validating the connection of button to GPIO
I drew a schematic of connecting button to GPIO with input mode with built-in pull up / pull down resistor:
Is it a true connection? if it's not, can you fix the problem?
The thing I want to do is so ...
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BeaglePlay bootstrap diodes
I would like to utilize the bootstrap design of the BeaglePlay board (schematic: link).
In case the User button is pressed the GND gets connected to BOOTMODEx.
What is the role of the diode(s) here? ...
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74HC595 drive strength
I understand that "drive output" on this datasheet means that it's the maximum current the IC can source/sink - i.e. if there is something pulling one of its outputs high at a current higher ...
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