The Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. The design is based around a ...

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64 views

Ultrasonic Sensor Controller

I am working on a project at school where we need sonar input to control a little vehicle. Pretty simple stuff, usually. However, we're having a bear of a time getting the sonar to work. My faculty ...
3
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3answers
497 views

Powering a Raspberry Pi from 12 V DC

I new to electronic engineering and am trying to learn electronic engineering by creating little projects. I have a few questions about powering my Raspberry Pi (5 V DC @1000 mA) from a ...
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1answer
38 views

AVR ISP-Programing LEDs SCK

I'm using a Attiny45 microcontroller and USBtinyISP as my programer, and this is the first time I need to hook stuff up (in this case just LEDs, but eventually I'll want to conect a raspberry pi) to ...
0
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1answer
44 views

How does a CD-ROM rotor know when to stop the moving plate?

I need to make a mechanism with a RaspberryPi like in CD-ROMs, so I can easily move a plate from the minimum position (CD-Rom closed) to maximum (CD-ROM open). I have a DC motor (from CD-ROM) and I ...
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1answer
19 views

Pi4j port for pcduino

Do you know any port of Pi4j for PCDuino boards or anything similar? I am particularly interested in I2C, oneWire and Serial reading.
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2answers
69 views

5V wallwart to 4 USBs and 3Pin fans

I am working on a small Raspberry Pi cluster that I am going to use for web hosting, home automation, cloud storage, VPN, and so on. I plan on using the 3D printer and laser cutter/engraver at my high ...
0
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1answer
42 views

2 sources one speaker - for old rotary phone

I have built a "mobile" phone using an old GPO 746, a Raspberry Pi and an old Nokia 6301, amazingly I have managed to get the audio to/from the phone's 2.5mm jack plug to through the GPO handset, ...
4
votes
1answer
72 views

Wheatstone bridge sensitivity and accuracy

From my earlier question I was able to wire up 2 SEN-10245 weight sensors (each forming one half of a wheatstone bridge) with an AD620 InAmp & 47 Ohm resistor (to set the gain to ~1000). I then ...
2
votes
1answer
25 views

Is it possible to use the RTS pin as DTR?

I'm deveoloping a project with a raspberry Pi that involves serial communication. In order to properly handle voltage levels, I used a max3232 converter between the raspberry and the external device ...
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2answers
70 views

Bidirectional driving solenoid using H bridge and raspberry pi

I want to drive a old phone ringer solenoid bidirectionally (20 Hz) using raspberry Pi GPIO pins. I am new to electronics, but I thought a H-bridge design would work to do this: The solenoid is 500 ...
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1answer
59 views

Appropriate electronics to use for scoring closest Nerf football air cannon shots? [closed]

Appropriate electronics and sensor technology to use for scoring closest Nerf football air cannon shots? The general concept would be to have a target area marked on the ground around a target device ...
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1answer
31 views

Slice of Pi wiring

I'm trying to wire a Ciseco Slice of Pi. I need to break out the 3v3, 5v and GND solder pads as I need several of each. There's no track between the pad and the holes I want to use. I could wire ...
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2answers
91 views

How to create USB toggle switch controled by GPIO

I have Raspberry Pi setup as NAS. The storage is external HDD powered through USB. I would like to encase this whole thing in some nice box and still be able to easily use the HDD, without ...
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0answers
49 views

PIC16F767 as SPI Slave: Can't clock out data

I have a Raspberry Pi and a PIC16F767 connected via SPI. The rPi is the master, the PIC is the slave. I can write data to the PIC just fine and dandy, but I can't seem to get the PIC to clock data ...
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2answers
68 views

Sensing weight with strain gauge, InAmp, ADC & Pi

I have an SEN-10245 sensor for weighing objects (essentially a strain gauge). The goal is to capture data with a Raspberry Pi, so the signal from the weight sensor needs to be amplified and then ran ...
2
votes
1answer
60 views

Understanding 74LVC245 datasheet and current source/sink

I'm using a SN74LVC245A (datasheet) to shift 5V TTL down to 3.3V so I can read the signals with a Raspberry Pi. However I am getting really weird results (a 60Hz input signal is picked up by the Pi ...
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3answers
132 views

Proper usage of a MOSFET to control USB

On the RaspberryPi.SE it was suggested that one can use MOSFET BS170 to switch a USB device on and off by a GPIO pin (3.3V). I need to get 500mA to power a GSM dongle; the voltage drop should ...
1
vote
1answer
64 views

Breadboard Wiring with Seven Segment Display

So I'm planning on building a skee ball machine and as I've been looking into it I've decided to use some seven segment displays from here: As I've looked into this more I know I need a breadboard ...
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0answers
65 views

Is it possible to do an AM transmission using Raspberry Pi for transmitting analog TV signal?

I have a Raspberry Pi model B and I want to transmit a TV signal using the TX pin on the Raspberry Pi. The TV signal enters the Raspberry Pi from the USB port using RTL-sdr. Is it possible to do ...
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1answer
84 views

What is wrong with this SPI implementation

I designed a system with RaspberryPi and STM32F407's, communicating with each other via SPI interfaces. For the last 3 months, tests were OK but yesterday a RaspberryPi and 2 of STM32F407's SPI ...
3
votes
3answers
321 views

Can I screw up my board by guessing which RS232 pins are which?

I have a Raspberry Pi that I want to hook up to a serial (RS232) cable. I've found and read some information about this, so I know what pins on my RPi are Rx/Tx/3.3V/Gnd... Now the cable I'm hooking ...
2
votes
2answers
145 views

Is a N-Channel Mosfet save/reliable for level shifting UART from 3V3 to 5V?

I am busy with a design that needs to connect a Raspberry Pi to an Arduino via UART. Previously I have designed a circuit that worked okay. But now I want start using SMD components and is planing ...
0
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0answers
33 views

Why mobile/raspberry-pi charger configuration mention both volts and current? [duplicate]

For example, a standard charger for RaspberryPi menetions 5V/1.5A, some mobile charger mentions like 5V/0.5A . Now, it might sound like a noob question, but isn't Mobile/Raspberry-Pi or any other ...
2
votes
1answer
72 views

Laser controller project

The context is that I want to build a tunnel laser effect, that modulates the angle of the cone according to a sine wave. The purpose being, to create a cool Borg weapon effect for a Star Trek Borg ...
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1answer
64 views

Detecting vehicle on parking spot

For a project we're working on we need to detect if a car is standing on a parking spot. We're using an ultrasonic sensor for this, SRF05. While using the correct timings we can only sense for about a ...
6
votes
3answers
498 views

Can I do this tutorial without a potentiometer?

I am trying out online tutorial to practice python and Raspberry Pi. I am currently following this tutorial. It says a potentiometer is needed, but I don't have one. The lcd I have is JHD162A What ...
2
votes
3answers
90 views

Do you always need a GPIO expansion chip when using i2c?

SUMMARY: I'm trying to learn the basics of understanding how to wire up a simple circuit using the i2c. I'm wanting to build just a simple project involving an LED and a push button with my raspberry ...
1
vote
1answer
194 views

Driving a LED matrix wall clock display (e.g. 64x16) from a Raspberry Pi?

My goal is to create a single-colour LED matrix display to show world times for several cities - e.g.: ...
3
votes
2answers
157 views

Cannot get a digital square wave on oscilloscope from the GPIO of the Raspberry Pi?

ENVIRONMENT: Running "Raspbian" on Model_B Raspberry Pi (Revision 2) w/ ribbon expanding the GPIO out onto a Breadboard as shown in the following image. SETUP Here is a close up of the GPIO ...
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vote
1answer
115 views

How many LED lights can 1 Raspi control

I asked a question on Raspberry Pi Beta regarding Using one Raspi to control long (>100ft) of 5V LED strip, one answer in particular I found this answer useful, with a further comment which advised me ...
1
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1answer
64 views

Connecting a current follower to a Raspberry Pi with an MCP3008

One of the experiments I conduct in an instrumental methods class is the construction of a rudimentary spectrophotometer described in the Journal of Chemical Education (link here if you have access to ...
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3answers
120 views

Serial connection between Raspberry Pi and Roomba

I have a Raspberry Pi with this FTDI cable and a Roomba 560. The Roomba has an SCI port to allow for control of the roomba via serial. I installed the PySerial library on the pi and send valid ...
10
votes
5answers
787 views

Control the hardware of an old phone using a Raspberry PI

I have a very old phone (60 years old) and I want to control its part using a Raspberry PI: Microphone & speaker from the head set The bell The dial wheel I have the electric circuit but don't ...
1
vote
1answer
210 views

How to modify DS1307 RTC to use 3.3V for Raspberry Pi?

I bought DS1307 RTC but it is 5V so it can't be connected to the Pi. I know it can be modified to use 3.3V by removing 2 resistors. This sensor is different than the adafruit kit so I am not sure ...
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1answer
44 views

What are the LE (latch enable) and the CLK (serial Clock) pins on the TQM8M9077?

I'm new here, so bear with me. I'm working on a sdr board for a raspberry pi and I have selected the TQM8M9077 as my DVGA. While looking at its datasheet and I came upon a few questions. What are the ...
1
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1answer
129 views

Using a FTDI to USB adapter with a raspberry pi and a roomba [closed]

I'd like to control a Roomba 560 using its 8-pin mini din SCI port. I've seen other people do this successfully but I'm still unclear on how exactly to go about this. I was planning on using an USB to ...
3
votes
2answers
99 views

External power for Raspberry Pi USB device

The Raspberry Pi's USB ports can only supply about 100ma of 5V current; this comes directly off the 5V input power to the board. The usual solution is to use a powered hub to support devices that ...
0
votes
1answer
335 views

How to wire external power supply on stepper motor

I followed this tutorial to setup my stepper motor. Now my stepper needs 12V and not 5V. So I was wondering how I can add an external power supply without destroying my pi. I found this: But it ...
1
vote
3answers
244 views

Step up DC-DC converter for powering Raspberry Pi from batteries

I will power a Raspberry PI with 4 NIMH batteries, but they quickly lose charge, and end up at 3V instead of the 5V needed. I was wondering about a DC-DC step up converter. I want a converter that ...
0
votes
0answers
50 views

Using PIC16F707 and Raspberry Pi for Touchscreen display

I've been asked to make a static touch screen for a store display with a very low budget. Due to the cost limits and large number of 'buttons' required, I've considered the PIC16F707 since it has 32 ...
8
votes
3answers
1k views

Breadboarding a Raspberry Pi

Ok, long time reader first time asker on this parcticulair stack-exchange. I am rather new to electronics, I've done some simple projects like Blinking Lights, alarms that go on when its dark and a ...
0
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0answers
111 views

Snapdragon 200 vs Raspberry Pi

I and a few friends are creating our own games console, and I would like to ask a question on our behalf. We're all teens, so making our own Hardware is implausible. So, we were considering Either a ...
0
votes
1answer
76 views

Raspberry pi with direct relay

I have a very back to basics question. I've been using a 5v relay with the raspberry pi. The relay trigger is connected directly to an output pin and the other side is connected to the ground of the ...
2
votes
3answers
110 views

Why does my switch need to be wired in this fashion?

Today was my first foray into electronics since high school, in the form of some simple Raspberry Pi experiments. I managed to get a circuit working where a switch controlled an LED with a ...
1
vote
1answer
165 views

RaspberryPi I2C sensor - capacitor's role

I'm new here and the same goes to my electronics "history". I like to understand things I'm dealing with even if I wasn't provided with a sufficient knowledge background at schools. What I'd like to ...
2
votes
1answer
121 views

Tradeoffs of XBee vs. Wifi for remote sensor & camera

I'm planning to build a remote sensor for my driveway gate, which is about 250' from the house (line of site). The basic requirement is to notify my HA system when the gate opens or closes, but I ...
3
votes
1answer
136 views

Externally Powered USB Port

I have a Raspberry Pi and it requires a Externally Powered USB hub to run Portable HDD on it. So what if I connect +5 and GND port of the USB Client to external power source of 5V-1A directly rather ...
2
votes
1answer
226 views

Reading and writing CAN messages through ELM327

I have an OBD-II cable, and an UART-to-OBD-II board which has the ELM327 IC in it. I want to communicate with my ECU by sending-receiving CAN messages. Is it possible to communicate through ELM 327? ...
0
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0answers
391 views

Digital Potentiometer (MCP4131) with Raspberry Pi

I'm very new in electronic stuff. I'm used to develop for desktop and mobile applications not for hardware products. I try to wire up my Raspberry Pi board with a MCP4131 Potentiometer. But it's not ...
2
votes
3answers
194 views

Logic level converter for H-bridge and UART for Raspberry Pi

Here is my situation: I'm using a raspberry Pi to control a H-Bridge. The H-Bridge is not tolerant of both it's inputs being high logic value, which causes a short through the transistors, bypassing ...