Hot answers tagged

17

I believe they have their own in-house designer who created the images you're referring to, as discussed here: Our new in-house designer Sam has produced the templates along with a brilliant set of icons, components, characters, illustrations and bespoke GPIO and wiring diagrams. That being the case, the likely candidates are Illustrator and ...


16

Assuming here you want to create similar images to what Raspberrypi.org provides (your question asks how the images are made, but you do not provide a reason why you want to know this): You can create similar diagrams using the Fritzing open source circuit design software, downloadable at http://fritzing.org/home/. Output looks like this: You can then turn ...


8

The black housings are available for more than just one contact, as one row or two row version. The contacts are crimped to the wires , which means you either have a crimp tool or somehow solder it. Ideally, you can use your cable, remove contacts from the housing, and just push them into the bigger housing. Edit (by Milliways) To add to the answer I have ...


6

You should connect GND, 5V and 3V3 to the appropriate pins on the pi. Then MOSI and MISO are also marked in the picture, SCK should connect to SCLK (this is the 10MHz clock which should be driven by the pi) and finally connect the CS pin to CS0 (Chip-Select, so you can connect 2 SD or other SPI-compliant devices). According to the first reply on this thread,...


6

You are correct: Would the adapter need any kind of chip on it? Yes it would - and the whole thing would be called a MicroUSB to Ethernet adapter! For the record the advert on a well-known auction site you linked to (which won't be around for too long so will suffer link-rot) was for a short lead with an RJ45 connector on one end and a micro-USB on the ...


5

It seems like it is a SPI device. You should first need to enable SPI using raspi-config. Then you'll need to wire: (Reader) GND -- GND (GPIO-Raspberry Pi2) 3V3 -- 3.3 V (Pin 1) 5V -- NC CS -- GPIO8 (Pin24) MOSI -- GPIO10 (Pin 19) SCK -- GPIO11 (Pin 23) MISO -- GPIO9 (Pin 21) ...


5

Lots of folks do that. You may need to add some small capacitors on long cable runs to reduce and RF interference that a long unshielded cable can pick up.


5

I do this all the time. Ethernet (Cat5) cable is twisted pair, which provides you with cross-talk protection. Note that the longest run I've used is about 36", so you may have to do testing to ensure you're not receiving interference at long distances if that's what you're wanting to do.


4

Are you looking at the correct I2C bus, between rev 1 and rev 2 the GPIO header was changed from using I2C 0 to I2C 1, see eLinux - RPi Low-level peripherals for details of the various pin changes. i2cdetect 0 i2cdetect 1 should scan both buses separately, if your devices show up after one of the calls then that is the bus they are on. Failing that if you ...


4

As I read your question, you need to power the Coin Acceptor using 12v, and reading the output using your RPi. To power the Coin Acceptor it is best you use an external power supply, as the coil in the acceptor might reset the RPi as it draws a relative large ammount of current when it operates. Find a 12v power supply, connect - on the PSU to a common ...


4

you need only 1 (one) ground pin for does not matter how many input buttons. there's absolutely no reason to use any other pin as a ground as long as you have one already used.


4

I don't use those functions so this is gleaned from the documentation. The basic pulse unit is 100 micros long. The final paramater in softPwmCreate says how long each cycle is in basic pulse units. softPwmCreate(1,0,200) says create a cycle 20 ms long made up of 200 steps (20 ms as 200 * 100 = 20000 microseconds). softPwmWrite(1,185) says keep the pulse ...


4

DIY with GIMP Based on the education resources of the Raspberry Pi Foundation and the SVGs of Fritzing, you can create your own diagrams with GIMP: Example images: Raspberry Pi 3 B+ (get a version without the white background here) breadboard red LED 220 Ω resistor push button I used paths in GIMP to draw the jumper wires. Watch this tutorial to see how ...


4

Wiegand is quite straightforward. It is not a particularly onerous interface. For an example of transmitting Wiegand codes see http://abyz.me.uk/rpi/pigpio/examples.html#pdif2_tx_WD /* This programs transmits Wiegand codes on a pair of GPIO. It is intended to be used to test Wiegand decoding software. REQUIRES Nothing TO BUILD gcc -Wall -pthread -o ...


4

The problem The problem is that your relay board is designed to run at 5V, but your Pi's GPIO is 3.3V. The relay is a 5V relay, so the power supply needs to be 5V, but you can alter the design of the driver board slightly to make it work at 3.3V input. Looking at this image, we can clearly see the transistor is marked 2TY which means it's an S8550 PNP ...


4

Do NOT use a resistor; on the contrary the resistance of the leads on many power supplies is too high (even though a fraction of an ohm) which causes low voltage problems for many Pi users. Use generously sized leads to connect to the Pi. The PSU you show is suitable - they have good regulation. I use a similar model to power up to 4 Pi. NOTE the comments ...


3

Checkout http://elinux.org/RPi_GPIO_Interface_Circuits R2 should be ~100kΩ R1 is not strictly necessary with a MOSFET, but does not harm, and provides some protection if you make a bad connection - use ~1kΩ. This must be a pretty hefty solenoid if it needs 320mA @ 12V. Don't worry about the voltage ratings of the diode or MOSFET ~50V will be OK, but you ...


3

According to this posting the 3.3v supply comes directly from the power supply on the Pi while the GPIO pins come from the BMC chip and can only supply a limited amount of current. That can explain why your solenoid energizes when connected to the 3.3v supply and not from the GPIO pin. I suspect that you need to wire the solenoid as shown below (which is ...


3

For 1000 lumens you can go two ways: Follow the design using the Solid State Relays. This is a classical approach. The RPi GPIOs control the relays and the lamps have external power (12V or mains power) switched via the relays. You can also use electromechanical relays. There are 1000 lumen LEDs. YOu need extra power for them as well. I don't think the RPi ...


3

The DHT11 specs are available on the www. You need a pull-up on the data line. It's quite safe to use the DHT11 without a pull-up on the data line, it just will not work. For the Pi it is safest to use a 3V3 pull-up. If you use anything higher you may damage the Pi. The Adafruit software for the DHT11/DHT22 works occasionally. More reliable software is ...


3

The baseboard you are referring to doesn't just seem to link the GPIOs, it also seems to have a 3V3 voltage regulator, a independent power supply, and likely a lot of resistors and other components on it as well: Source The board connects to the GPIO P1 header on the P1 (the big one in the corner), which has the following Pins: Source: http://elinux.org/...


3

Your fan probably has a voltage drop that is too high for the Pi's GPIO to power it. The GPIO pins only output 3.3v 50ma MAX.


3

For starters your design is intrinsically flawed, you will have to make another implementation of what you want to do. The explanation of why it is flawed is two fold. Your potentiometer. The center tap is connected to the piezo, left to 5V and right to GND. A GND connection is unnecessary because a R in series with the piezo is enough to limit the current ...


3

That is not so good. So the 3.3V power pin from the RPi is connected to the breadboard's top-most rail via a red jumper (note this isn't actually used by the rest of the circuit but I don't believe it harms anything, right? Correct, it is pointless that way. When my software (running on the RPi) fires a signal to the buzzer via GPIO output pin, the ...


3

I am interpreting the picture of the printed circuit board of the relay module with accompanying notes as follows: the board includes a transistor and a diode - and while it is impossible to tell from the image without looking at the wiring and/or schematics - it is reasonable to believe this is the freewheel diode you're refering to. Conclusion here: no ...


3

I think I found what you are looking for : In this exemple, we see that two switches are controlling one lamp, so toggling one of these switch will toggle the lamp. In your case, you need to consider your relay as the first switch, and your pre-existing switch as the second one. Image taken from : https://diy.stackexchange.com/questions/31632/wiring-a-...


3

The double switch method (also called a staircase switch) would be preferable, as it's easier to integrate with existing wiring, but it leaves your Pi without knowledge about the state of the load. As I see it you have two options: Make the switch pull an input high or low on the Raspi, which you then use in your code to control the lamp or other load ...


3

Don't put any resistor in series with the Pi when connecting it to a voltage source. — Uh, and 10A is overkill. You can't run 10A through the 5V tracks on the Pi's board. These are for about 2A only. You can of course run another set of +5V/GND wires to the devices you want to control with the Pi. The reason you use a series resistor for LEDs is that they ...


2

Your program is possibly segfaulting because have swapped the loop and post-loop statements while the function does not return a meaningful value. Consider: int keyinterrupt (void) { int col[] = {COL1, COL2, COL3, COL4}; int row[] = {ROW1, ROW2, ROW3, ROW4}; int reset; for(colnum = 0; colnum++; colnum < 4) { // .....


2

I've also looked into this and came across Sainsmart 8 Channel 5V Solid State Relay Module Board. The 3v3 voltage of RPi GPIO will drive the input side, separate 5v control for driving the unit and 75-250v @ 2A output. Additionally, the relays are driven optically, so very quiet as well.


Only top voted, non community-wiki answers of a minimum length are eligible