Questions tagged [raspberry-pi]

The Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. There have been several generations of the device with improved performance, more memory, and more connectivity. This tag should be used for electrical engineering questions that involve the use of a Raspberry Pi. For questions about the Raspberry Pi itself see the Raspberry Pi specific forum (raspberrypi.stackexchange.com).

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3 votes
1 answer
748 views

Raspberry Pi CM4 SD card breakout

I am designing a carrier board for the RPi CM4 Lite (no eMMC) and having trouble understanding the documentation. The CM4 proved a SD_PWR_ON and ...
3 votes
2 answers
777 views

Control 5 V relay board with Raspberry Pi GPIO

I would like to control one of these 8-relay boards with my RPI GPIOs. Please check the below schematic - it shows the parts involved for one of the 8 relays. JD-VCC is connected to the 5 V of the RPI,...
0 votes
0 answers
27 views

Raspberry Pi DAQHAT: Overvoltage issue

I am working on development for a piece of HV test equipment, where I need to monitor the voltage output for a circuit that is actively arcing. I am measuring the voltage off of a Raspberry Pi DAQHAT (...
-1 votes
1 answer
282 views

Using TP4056 to charge a battery with an NTC

I'm hoping its not a duplicate question but I currently have a TP4056 and the following lipo battery: Pijuice zero 1000 mAh battery. I'm fairly new to electronics and was wondering in this case what ...
0 votes
2 answers
659 views

How to reduce voltage with no earth?

I'm currently working with Raspberry Pis that are going to be powered through an LED night light (it is for being able to observe people working on experiments and giving light to the camera.) The ...
0 votes
2 answers
89 views

Actively stabilizing voltage through a Raspberry Pi CM4

I am building a project using a Raspberry Pi and a decently sized LCD screen and NVMe SSD. These things draw a lot of current together, and they cause a significant voltage drop in my system. The CM4 ...
0 votes
1 answer
220 views

Powering Raspberry Pi 4 with ~6.1V BEC

I have a LiPo battery with specs 7.4V, 5200mah (50C if it is relevant), that I am trying to use to power a Raspberry Pi 4 for a project. I am using a BLDC motor in this setup, so I am trying to power ...
0 votes
0 answers
24 views

Power + input DC relay from singular source via SPDT toggle switch

I hope I'm not reinventing the wheel here. I'd like to separate two circuits (charging and discharging circuit) as I'm making my own tablet from RPi and bought in LiFePO4 powerpack. For my piece of ...
1 vote
1 answer
357 views

Protecting RPi against lightning and high voltage

I'm making a remote weather station with a Raspberry Pi 4 and a few sensors. Problem 1: the anemometer is held on a iron rod (was already there, can't change), dangerously exposed to lightnings. ...
3 votes
1 answer
318 views

Stepper motor only vibrates, not turning. Seeking advice or help

I recently purchased a SF2421-10B41 stepper motor and a Stepper 5 click board (TMC2208 driver IC built in) for my project, using Raspberry Pi 3B for programming, below is my sketch and the datasheet I ...
1 vote
1 answer
1k views

How to switch ON a Raspberry Pi, Arduino, ESP32, etc from SQW pin of RTC DS3231

My issue is how to build the circuit and what is the most efficient one to trigger a MCU from the alarm of the RTC DS3231. For the momment I have built the one in the picture below (using a P-channel ...
-1 votes
1 answer
260 views

Connect servo and DC motor to Raspberry Pi

I'm currently working on a project where I have built an RC car with one DC motor (forward/backward) and one servo motor (steering). I'm a newbie with electronics so I figured out by myself I needed a ...
-1 votes
1 answer
617 views

Raspberry Pi UPS circuit review request + improvements

Based on this question I created the following circuit: Since I made some (component) changes, first I would like to have a validation of the circuit for long-term usage (and some improvements). Used ...
2 votes
1 answer
3k views

LCD driver board M.NT68676.2 issue: Screen compressed, fills only part of display

I am trying to build a portable Raspberry Pi/Retropie system with an LCD screen I got from my old laptop (the idea is to have a portable gaming console to be used in a car). To drive the screen, I am ...
0 votes
0 answers
42 views

AD677JNZ Raspberry Pi Connection

Relatively new to electronics, I would like to connect the AD677JNZ analog-to-digital (ADC) to a Raspberry Pi 4 to monitor the voltage of a potentiometer. However, I am having issues with the ...
0 votes
1 answer
700 views

Looking for a three state relay or switch

I need to control the link between three wires: Nothing touches == State 1 == Light is off Red touches brown == State 2 == Light is on Red touches grey == State 3 == Light blinks A little drawing: ...
1 vote
1 answer
336 views

Powering 10V motor fader in Raspberry Pi 4 project

I am building a project that uses a motorized slide potentiometer with a Raspberry Pi 4, for the purpose of controlling multiple audio sources (such as system volume, VLC, OBS, and any other I can ...
1 vote
1 answer
232 views

Overcurrent protection relay: how do I simulate it with a Raspberry Pi?

I'm using an RPi and an MCP3208 to simulate an overcurrent relay. I managed to level-shift the AC signal and now I get the voltage reading at 0-3.3 V. As this is an overCURRENT relay, I was stuck for ...
3 votes
1 answer
75 views

Stepper Motor Interference from Metal on Frame or Shaft

I'm working on a project with a stepper motor and am running into an odd interference issue related to metal contact with the motor. I'm using a StepperOnline Nema23 2.8A (23HS22-2804S) motor with a ...
0 votes
1 answer
121 views

I am using a logic level converter for my LED-Ring but it's not working

I am working on a small project where I am using a SparkFun Lumini LED Ring. The power supply for the ring is external, connected via its own cable and power adapter. I have connected the ring to the ...
0 votes
1 answer
324 views

candump and cansniffer are working but cansend is not working on Raspberry Pi + RS485 CAN HAT (MCP2515)

I connect it at 500k bitrate. Both candump and cansniffer are working, receiving a lot of messages. I've pinned down the packet ...
0 votes
2 answers
478 views

Help with understanding the Memory Map of MLX90393

(Using a Raspberry Pi 3 Model B+ and python) I needed some assistance in understanding the memory map of MLX90393 I've attached the memory map here and you could also find it in the datasheet. I'm a ...
1 vote
2 answers
316 views

Low/mid/high 230 V fan control with Raspberry Pi

I have 230 VAC, 300 W fan, a SRD-05VDC-SL-C relay, and a Raspberry Pi. What other equipment would I need to control the 230 VAC fan with a Raspberry Pi? I want to go 0/1 with relay, and in mode:1 be ...
0 votes
1 answer
511 views

How to detect when an LED has burned out?

I'd like to have a way to detect when a low power LED burns out (2-3.5V, 200-400mA) that is being driven using PWM from a Raspberry Pi with a MOSFET. My understanding is that I would be able to ...
1 vote
1 answer
354 views

WS2813 Lead Wire Issues

I've wired a set of WS2813 leds to a Raspberry Pi. The led strip is found here: https://www.amazon.com/gp/product/B077J27Y4X/ref=ask_ql_qh_dp_hza When I have this strip connected via the short cable/...
0 votes
1 answer
70 views

Controlling Motor Speed with MCP4162-104E Digital Potentiometer

I am new to electronics and this is my first time using a digital potentiometer. My goal is to control the speed of a DC motor using the MCP4162-104E digital potentiometer. I am confident in the ...
0 votes
1 answer
211 views

How can I accurately find the distance between two drones over moderate distances?

I am currently taking part in a project in which I am building drones using Arduinos and Raspberry Pis, and I need to be able to measure the distance between the drones. After some research, I ...
1 vote
0 answers
81 views

Electrical Noise in Raspberry Pi with Multiple USB Connection

I'm currently in the process of creating a mobile robot using a Raspberry Pi. The robot incorporates three devices (ODrive, RPLidar, and UWB), all connected to the Raspberry Pi through USB ports. When ...
0 votes
0 answers
105 views

Bipolar stepper motor buzzing and heating with a DRV8825 driver

I followed these instructions to drive a couple of stepper motors from a Raspberry Pi 4B and two DRV8825 drivers. I made the board, plugged in the 16 pin drivers, wrote a Python script to instruct the ...
0 votes
1 answer
106 views

My LED ring is not working when I connect the GND [closed]

I am working on a small project where I am using a SparkFun Lumini LED Ring. The power supply for the ring is external, connected via its own cable and power adapter. I have connected the ring to the ...
1 vote
1 answer
58 views

Current leakage when measuring battery voltage via Raspberry Pi and MCP3002

I have a project involving the following components: Raspberry Pi Zero W MCP3002 (Datasheet) Adafruit PowerBoost 500C (using a TPS61090) The Setup: The MCP3002 is connected to the Pi via SPI0 (pins ...
0 votes
1 answer
235 views

Level shifter for interfacing SCD41 and Raspberry pi over I2C

I am connecting an SCD41 CO2 sensor to a Raspberry Pi Zero 2 W. To keep the 3.3V current draw low, I would like to power it at 5V (peak current is 205 mA at 3.3V vs. 137 mA at 5V). A TXS0108E module ...
1 vote
1 answer
165 views

Switching relay with 2N7000 and Raspberry Pi GPIO

I'm debugging a circuit on a home project and hoping for some advice. I have a relay set up like so: The behavior I'm seeing: When I toggle the Raspberry Pi GPIO to ...
0 votes
2 answers
328 views

Passive Infrared (PIR) Motion Sensor

I want to have the PIR Motion Sensor: https://www.adafruit.com/product/189 Used to turn on a light whenever it detects motion. Simple enough, but would it be possible to have this done wirelessly? ...
1 vote
1 answer
249 views

Is it possible to have two SPI controllers and one SPI peripheral?

I have one Raspberry Pi 3 Model A+ and one Raspberry Pi Pico. I want to allow both of these devices to write and read data from this SD card reader: https://www.adafruit.com/product/254 How should I ...
1 vote
1 answer
771 views

Corruption(?) of the Raspberry Pi Pico's UART characters with the C SDK

I'm making a remote controlled machine using a Raspberry Pi Pico to drive the motors and read some sensors, and a Raspberry Pi 4 to send commands to the Pico via serial and host the web interface. I ...
2 votes
1 answer
2k views

Trouble using the UART with Raspberry Pi Pico

I'm making a remote controlled machine using a Raspberry Pi Pico to drive the motors and read some sensors, and a Raspberry Pi 4 to send commands to the Pico via serial and host the web interface. I'm ...
0 votes
3 answers
747 views

Replace some LEDs with diodes in relay circuit

I need to know if I can replace the input LEDs (IN1, IN2, IN3, IN4) by a diode or resistor and if this can help me to reduce the voltage consumption generated by these LEDs. The circuit is a 4 relay ...
1 vote
2 answers
2k views

ESP32 UART to Raspberry Pi I2C

I am trying to understand how to connect an ESP32's UART pins to my raspberry pi 3B+'s I2C pins. I see several bridge chips available for this like TI's MSP430 Datasheet. But I am not very circuit ...
0 votes
1 answer
808 views

How to receive input signal on Raspberry Pi GPIO from transistor emitter

I'm trying to build a simple circuit that allows a Raspberry Pi to detect AC voltage in a piece of wire inductively. I have the following circuit which basically uses an antenna wrapped around the ...
0 votes
1 answer
237 views

Powering 1920 leds with 32 strips of 60 ws2812b led strips each (32 meters)

I'm tring to build a led display with 32 strips of ws2812b led strips with 60 leds each. That's a total amount of 1920 leds. How many power supplies should I buy? Given the max current of 50mA per ...
2 votes
1 answer
73 views

Building a power supply for a Raspberry Pi 4 but having trouble with the output voltage of regulator

I am using a LT1529-5 regulator to drop 12 V 2 A down to 5 V 3 A to power a Raspberry Pi 4 from a different wall DC power supply. When my circuit is unloaded, the output is maintained at 5 V. When I ...
0 votes
1 answer
6k views

Raspberry Pi Pico 3.3V_EN pin control voltage inquiry

I am trying to turn on or off a Raspberry Pi Pico using a Raspberry Pi Model 3. The Raspberry Pi Pico seems to have a 3.3V_EN pin which is basically the 3.3V regulator enable pin (3V3_EN) pulled up to ...
2 votes
2 answers
300 views

Circuit for high-voltage pulses using Raspberry Pi PWM to drive a piezoelectric actuator

I am trying to engineer a device to separate red blood cells from blood plasma in 100mm x 1mm capillary tubes using the Raspberry Pi GPIO pin PWM feature and a piezoelectric actuator. The pulses ...
1 vote
1 answer
633 views

Connecting a 240 V PIR motion detector to a Raspberry Pi

I want to connect a 240 V PIR motion detector directly to my Raspberry Pi 3. Inside its plastic case I found two PCBs. One is the power supply board which has a 24 VDC relay, an S9013 NPN transistor, ...
1 vote
1 answer
98 views

Inconsistent resistance measurement in H-bridge

I have an H-bridge circuit that is meant to measure the voltage across the shunt (330 resistor) and load (pictured as 4700, but variable) to calculate the resistance of the load (I have added the 10k ...
0 votes
2 answers
58 views

Is 74244 buffer suitable for multiplying data and enable in my Rasberry Pi3 to ATmega128A bidirectional communication?

My Raspberry sends data at baud rate 115200 to 300 remote panels (ATmega128A) through RS485 bus serial communication. Also it sends enable signal (5 V) and receive feedback from the 300 panels at the ...
0 votes
2 answers
443 views

Connecting KY-009 to GPIO of Raspberry Pi

We would like to connect the 3-color LED module (KY-009) to the GPIO pins of Raspberry Pi 3. We are going to use the {green, blue} LEDs only (5050 SMD LED) of the module. Because the LEDs require ...
2 votes
2 answers
386 views

Read multiple PT100 sensors with MAX31865

I'm building a temperature logger with four PT100 sensors. I've already decided to use a MAX31865 converter (just the IC), 3-wire PT100s and the device will be a Raspberry PI HAT - the PI will talk to ...
0 votes
2 answers
64 views

Three wire remote controller - wiring to two GPIO pins

My remote camera trigger has three wires (red, yellow, white). The white is shared, and the trigger can complete two different circuits by shorting it with either the red or the yellow cable. One of ...

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