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 ...
2
votes
2answers
35 views
Mini Skee Ball - Detecting a ping pong ball
Background
I really want to do something with my raspberry pi, so I thought of a game that's a mix between skee ball and beer pong. Basically, the build is a mini skee ball board (about 20x24 ...
0
votes
3answers
48 views
How do I connect this 3.3V system and 6V ish system together?
I have an old 'Cybot' robot I built from a kit. I'm trying to mount a Raspberry Pi on it to act as brains. I'm a computer programmer, but my electronics knowledge is very limited. Have access to basic ...
5
votes
2answers
85 views
Using a 5v voltage regulator - Capacitors necessary? Better options?
I am very new to electronics. I am learning as I go, and I haven't quite found the answers I need; when it comes to programming, I'm not afraid of mistakes as they happen constantly. With electronics, ...
1
vote
2answers
80 views
Bidirectional Level Shifter without IC
I'd like to connect R-Pi serial to PC's RS232 port without IC (such MAX3232), using only diode (thus block negative voltage to 0V), voltage divider resistors, and common BJT.
For TXD (RX from R-Pi ...
0
votes
2answers
100 views
Raspberry Pi GPIO
I need to make a connection between the "Device"'s 2 wires using a Raspberry Pi, but I am unsure how to go about doing this (and I don't want to just play about with it and get it wrong as I might ...
1
vote
0answers
63 views
Dimming USB Led Lamp
So, currently I have a project that consist in the following:
We have 2 USB Led lamps. (e.g 13 leds, 5V, ~200mA)
To these lamps, we would like to control the intensity of the light, through a ...
2
votes
1answer
53 views
Raspberry Pi: driving Servo with PWM
I'm experimenting with a small servo motor with the raspberry pi using PWM (pulse-width modulation). My understanding is that the servo should respond to different length of pulse. I should be seeing ...
-2
votes
2answers
77 views
raspberry pi + USB Hub [duplicate]
I bought a cheap USB Hub Powered to connect my Raspberry Pi and two External Seagate HD (USB 2.0/3.0), but obviously that 400 mA is not enough for all this things.
So, I want to buy a new AC Adpater ...
2
votes
1answer
78 views
Control old printer motor with position ring
I purchased two old printers at a garage sale today in hopes of dismantling them and playing around with some stepper motors. After tearing both of them apart I discovered that there are no stepper ...
2
votes
3answers
131 views
What do you use a board like this for?
I'll start by saying that I'm a software guy, I know literally nothing about electronics.
I recently bought a raspberry pi, and while browsing at my local electronics shop, saw this board for $5.
...
2
votes
1answer
89 views
How to connect a pulled motor from a printer to Breadboard and control with raspberry pi? [closed]
I managed to salvage a couple of motors from a worn down old printer, and I'm unsure of how to get about connecting it to a breadboard and then to a Raspberry Pi. I've got a cobbler kit for my Pi that ...
2
votes
1answer
103 views
Multiplexing large LED matrix
I have a project which involves building a 64 x 48 (3072) LED matrix driven by a Raspberry PI computer. I am a first-year computer engineering student so I am still inexperienced with shift registers ...
0
votes
1answer
82 views
Current flows from the source towards the sink
I happened upon the following schematic:
simulate this circuit – Schematic created using CircuitLab
It's supposed to reduce the max.voltage between the GPIO input pin and the current ...
1
vote
1answer
122 views
Is De0-Nano an alternative to Arduino/RaspberryPi?
Arduino and Raspberry Pi are touted as ideal programming boards for beginners and hobbyists. Could De0-Nano fit in that role, too?
What does Arduino or RaspberryPi have that De0-Nano does not?
3
votes
2answers
132 views
Manual SPI interface on Raspberry PI
I am trying to control a MCP4131 digital pot from my Raspberry Pi using the
library here
Using the GPIO pins, I am "emulating" an SPI interface. I bring the ChipSelect pin to low, write my byte, ...
1
vote
2answers
62 views
Peak voltage rating means voltage drop?
This LDR is said to have Peak voltage rating of 400V in the description. Does this equal the voltage drop, meaning that I need to supply at least 400V or is it the maximum voltage value?
0
votes
1answer
83 views
Multiplex two I2C ICs into four 7 Segment displays
I currently have two PCF8574AN I2C ICs. Is there a way I could have two seven segments be driven off one IC (So i could run four seven segments displays off the two ICs that I have). I have thought ...
2
votes
2answers
75 views
Using 2 different LDO with the same voltage in the same application
I'm using a Raspberry Pi and have designed an extension board (Like the Pi-face) but I have a question about the power supply. I need 3V3 on my board, but the 3V3 from the Raspberry is not strong ...
3
votes
1answer
91 views
Can I use Sn only solder for PCBs?
I bought the Raspberry Pi cobbler kit a while ago, and I needed to solder a part together. The local hardware store (Useless ACE) only has a specific solder, which has just Sn, a diameter of 1.0mm and ...
-3
votes
0answers
43 views
raspberry pi auto [closed]
Got a question on the raspberry pi, can you have an autoexec type file like in the old pc dos.
Am thinking of trying to make a pi download my photos from a card reader to a usb stick when travelling.
...
1
vote
0answers
102 views
Raspberry Pi vs Arduino ADK (with phone tethering)
I was doing some research for my capstone project next year. Basically it is an autonomous rover, designed to scout out outdoor areas and send back video/pictures to a website.
So far, our initial ...
5
votes
3answers
211 views
Serial bus Raspberry Pi to multiple AVRs
Background: I'm trying to replace the electronics for a ice hockey scoreboard. The old electronics had the following issues:
It stop working. I have since discovered that a couple of diodes and ...
1
vote
3answers
79 views
Higher resistance resistor in place of higher wattage?
Engineering newbie here. I'm fairly sure I already know the answer to the question, but I figure I'll ask anyway.
I've got an LED lying around, that according to an LED calculator requires a 80R 1/2w ...
0
votes
1answer
100 views
How can I decide whether I can use a Raspberry Pi for my application?
How do I calculate whether some specific hardware can run my code with a given speed?
It's an image recognition software, and a simplified version of the algorithm is:
Grab a frame (in RGB, ...
1
vote
0answers
73 views
How to properly turn off a Raspberry Pi when instant plug-out is a criteria [duplicate]
I want to create a stand-alone internet radio device. Therefore I want to use an existing subwoofer box with connected speakers. Inside the subwoofer box there is the electronics for the sound system. ...
2
votes
1answer
59 views
Frequency Scaling and current draw
I am trying to power a RPi of 4 AA's, and my mobile power device can only output limited current (500mA), but I can underpower my RPi by frequency scaling. Is frequency scaling and current draw a ...
1
vote
3answers
197 views
Convert 9v of battery into 5v at 3.5watt
I want to run Raspberry Pi using a general non-rechargeable 9v battery.
Raspberry Pi needs 3.5W and 5V input.
Questions:
Which LDO should i use ?
For what amount of time general 9V battery is able ...
1
vote
1answer
80 views
Interactive Single Color LED Matrix
I'm trying to build an LED matrix (32x16) that lights up in certain areas in response to movement, as detected by another matrix (8x16) of infrared phototransistors.
Here's where I'm at:
Main ...
2
votes
2answers
193 views
Can't Get Raspberry Pi and Xbee to Work Together
I am having the hardest time trying to get my XBEE's to work with my Raspberry pi (RP). I have one on a USB breakout board into my computer and the other XBEE connected to a RP. The one on the RP is ...
5
votes
2answers
476 views
Is the Raspberry Pi a microcontroller or a motherboard? [closed]
I had quick question regarding Raspberry Pi: is it a microcontroller or a motherboard?
It looks like a motherboard, but considering that it has its own dedicated memory and processor, it should be a ...
1
vote
1answer
134 views
Reading Array of Phototransistors With Raspberry Pi
For a project I'm working on, I need to read the values from a matrix of phototransistors (8x16) into the Raspberry Pi.
I'm not exactly sure how to go about doing this, since I know I need to include ...
0
votes
1answer
70 views
24-bit parallel TFT module on circuit designed for 16-bit parallel
I've designed a circuit that connects a 16-bit parallel LCD TFT module to the SPI-connector on a RPi, but bigger TFT modules often have 24-bit parallel. Can I use a 24-bit parallel TFT with my circuit ...
0
votes
1answer
106 views
Rasperry Pi Out to XBEE In
I am using the IO pass through mode on an XBEE, so basically if one XBEE has a high input, it passes that input to the other XBEE and that XBEE's output is also high. Since the Raspberry pi has an ...
2
votes
1answer
139 views
Power consumption and frequency
I am making a small, mobile device with the Raspberry Pi that depends on batteries, so power consumption is an issue. I have scaled the "arm_freq_min" (unsure if clock or instruction cycle frequency) ...
-2
votes
1answer
72 views
spidev_test.c analysis [closed]
I'm trying to connect a Raspberry Pi with a PIC32 through SPI. For RPi I'm using the spidev_test.c code (I'm modifying it to suit my needs) but... because I'm a novice in programming hardware, I'm ...
17
votes
3answers
884 views
What does “no fit” mean in electronics?
I have found at some places, especially:
Raspberry Pi Forums
eLinux RPi Hardware page
the following wording:
S2: DSI interface. 15-pin surface mounted flat flex connector
(possibly no-fit) ...
0
votes
2answers
114 views
IR Remote, use a relay to send on and off pulses
I have a little problem. I'm using the raspberry pi to send a output signal from the GPIO pins to activate / deactivate the relay. I have a IR remote, when i short the two "connectors" on (for example ...
-2
votes
1answer
115 views
Are there any split USB cables that can power two devices? [closed]
https://www.adafruit.com/products/501
I wanted to use this to drive two devices simultaneously (raspberry pi and peripheral).
I would like to have a y-cable - one end with a male Micro USB B-Type ...
1
vote
3answers
331 views
Simple step-up voltage regulator from 3.7V to 5V?
I have a 3.7V 4.4Ah li-ion battery and would like to use it to power my Raspberry Pi (which needs 5V and 700+ mA). What’s the easiest way to do it with minimum EE experience? Also, what resulting ...
0
votes
1answer
73 views
Why the Locking Buttons? (Project for blind user)
I was trying to build this: http://www.shaungehring.com/2013/01/03/raspberry-pi-project-1-pandora-streamer/ for a blind user. The large buttons are a key aspect for this target user. But, I've noticed ...
2
votes
1answer
427 views
Best way to communicate Raspberry Pi and ATTiny13
What is best way to connect two or three microcontrollers, ATTiny13 to Raspberry-Pi and get master (Raspberry Pi) communication? Are there any ready libraries for ATTiny13 for SPI or I2C? Maybe some ...
6
votes
4answers
1k views
Shutdown Controller for Raspberry Pi in a car
Following on from my previous question I'm trying to create a shutdown controller for my Raspberry Pi. The Raspberry Pi needs to be powered from the battery, but should power-down after the Pi ...
3
votes
3answers
228 views
Decoupling capacitor across Raspberry Pi GPIO input (+ Arduino + robotics)
I've been messing around with a robot kit from Parallax (the BOE Shield Kit), which has a 5xAA (7.2V?) power source. The BOE Shield includes its own 5V regulator, which is used to control servos that ...
2
votes
1answer
420 views
Raspberry Pi USB-to-Serial Atmega328
I understand you can create a serial transmission between the Raspberry Pi and an Atmega328 using the GPIO:
http://www.raspberrypi.org/phpBB3/viewtopic.php?t=22736&p=293668
I'm interested in ...
2
votes
2answers
180 views
bridge rectifier connected to a raspberry pi gpio
I'd like to connect a bridge (full wave) rectifier to my Raspberry Pi (RPi), GPIO pin 22 (configured as an input). I have configured the rectifier such that it has a 120VAC input and 3VDC output (I ...
-1
votes
1answer
170 views
Connection between RPi and PIC [closed]
Before I start I would like to say that I'm a complete novice with microcontrollers and would like to be treated as one and receive answers acordingly... more like "Q: How many legs does a human have? ...
2
votes
4answers
358 views
How do I reverse my electric motor?
For a pet project I am doing (trying to fly a kite using my computer) I need to move and reverse an electro motor to my liking (I took the motor from an old hand-held vacuum cleaner). I need to ...
2
votes
4answers
884 views
Circuit to safely power-down Raspberry Pi
I want to use a Raspberry Pi as an XBMC server in the car. The XBMC docs say that you should always use the shutdown command before disconnecting the power. I don't want to have to (tell my wife to) ...
0
votes
2answers
135 views
5v output to 3.3v?
I have a microcontroller and a Raspberry Pi, both running off of the same 5v supply, in parallel. The microcontroller has 4 5v output pins and the other is a Raspberry Pi, that can only accept inputs ...
1
vote
4answers
2k views
Python serial between Arduino and Raspberry Pi: Data is modified upon reception
I'm using an Arduino for sensor readings and sending them to a Raspberry Pi via USB, using PySerial for data reception.
It works great, except for the fact received data is awkwardly modified (And ...
