Raspberry Pi Forums

mark3112

As chipace said, much depends on what you mean by "program the FPGA". I worked on a project where a STM32 held the configuration information and used this to create the VHDL file that was uploaded to the FPGA’s configuration EEPROM. Normally this would be done via JTAG but the configuratio...

mark3112

“configure Apache to serve everything from a web root on your other media” That I like, will look into it. Thanks. I was going for a more primitive approach. When the page loads create a flag file, let the C code find the file and move the temperature data. Once it’s displayed, delete the files. The...

mark3112

It’s been a long time since I did anything with HTML and Javascript is entirely new to me so please excuse me if I get things mixed up. I am using Apache2 on the Pi as the web server and accessing it with Firefox on my phone. The program running on the Pi that creates the data, controls my (solid fu...

mark3112

I have a data logger program on my Pi monitoring my central heating. Every minute it updates a .csv file with the temperatures. I want to be able to access the data via a webpage using Dygraphs. Dygraphs can only access the file if it is in the www folder but I don’t want to store the data on the SD...

mark3112

GPIO PWM into a transistor that controls the current to the LED’s. If you don’t use the transistor there is a very good chance you will kill the pi.

https://electronicshobbyists.com/raspbe ... rvo-motor/

mark3112

As per Joan’s suggestion, try a zero crossing detector.
http://www.ti.com/lit/an/snoa999/snoa999.pdf

mark3112

How fast can you transfer data? Without checking the FPGA’s specs I think its internal maximum clock is about 400MHz. So, let’s play safe and divide by 2, so 200Mbs for the Cyclone III chip? Can you explain more ? Yep, what do you want to know? But I have only worked with Altera parts, many years ag...

mark3112

SPI works for me using a pair of shift registers. I have two 8 bit output latches and switch between them when data is being sent. That way one can be loaded whilst the other is live on the shift register.

mark3112

I used to use the dtoverlay command I don’t know if it’s still current though. Name: spi1-3cs Info: Enables spi1 with three chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. N.B.: spi1 is only accessible on...

mark3112

For a minimal CAN network take a look at Keil’s A Tiny Network without Transceiver ICs (bottom of page 4):

http://www.keil.com/download/files/canprimer_v2.pdf

mark3112

I’ve not used the MCP2551 and normally use SN65HVD251 but guess the CAN interface is the same. What are R1 & R2 for (the whole idea of CAN is that it is robust in noisy environments)? I would also lose R6 & R7 (at least during the testing phase). The other thing that jumps out at me is the 2...

mark3112

My 40 year old Pioneer SA-9800 died a few months ago, I was about to buy a new amp but out of curiosity I had a look on the net to see if there were any second hand ones. There was for $2500. Which made me think repairing it was a better alternative than scrapping it. If you fancy trying to fix it, ...

mark3112

Possibly a dumb question but I’m curious. Why do you need to measure the inside diameter? As the pipe expands, the outside must expand as well. OK, the wall diameter will reduce very slightly but would make measuring easier. If you can measure the outside, see laser diameter gauge (scan a laser acro...

mark3112

“we are looking to build our own sensors based on an RPI or similar platform” I’m with drgoff, that’s way too general. Are you looking to build a custom sensor module or a PCB housing commercially available components? The links don’t help when you try and dig down to the details and end up with a p...

mark3112

Linear potentiometer and an ADC?
Type “Linear-Position-Sensor” into ebay.

mark3112

At a guess it looks like the +/- indicate the Active Level of the signal.
So The Brake Status is true when + (12V)
Trunk Status is true when – (0V)

mark3112

The company I work for has sold about 500 Pi based Lighting Control Desks and expect to move about 1000 this year (want to test ruggedness? Give it to the Stage Crew). A new Pi product (office type lighting controller) that I am involved in has just reached the point of bulk deliveries to installers...

mark3112

Try a search on the phrase

Ultra Compact RS232 to TTL Converter with Male DB9

and you will probably want some conection leads to connect it to the header.

mark3112

I use a Microchip DALI Interface (DM160215) that works OK but its USB to Windoze (USB HID).
Have a look at DM160214-1, No comms channel but if you can rework the PIC code perhaps you could implement something.

mark3112

Possible? Don’t see why not. How much finesse do you want?
What sort of control? What other program?
Quick and dirty solution. Have a PowerShell script on the PC that occasionally pings the Pi.
When it responds.... (PowerShell gives you .NET and a relatively simple interface)

mark3112

Looking at the pigpio documentation: “gpioSetAlertFunc - [Polled] The GPIO are sampled at a rate set when the library is started. gpioSetISRFunc – [Event Driven] The GPIO is exported, set to be an input, and set to interrupt on the given edge and timeout.” Although I’m sure Joan could supply a bette...

mark3112

“The Interrupt on GPIO25 works fine from PICAN2, but it might be too fast for wiringPi to find it.” I don’t understand that, how can the signal be too fast when it’s software that resets the INT Line on MCP2515 - GPIO25? It could be a driver is reading the data and resetting the INT line? I drive 4 ...

mark3112

Have you set the RXnIE bit in the CANINTE register? I have a pi connected to 4 MCP2515 and initially used interrupts and wiringPI. A problem I hit straight away was the restriction of a maximum of two interrupts and the fact the interrupt handling routine was itself interruptable, which caused havoc...

mark3112

As you are connecting directly you don’t need RS-232 line drivers.
If the devices are very close just connect them TX-RX and RX-TX.
If they are not close you could use differential line drivers i.e. see SN65LVDS180

mark3112

Heater - “Lunar Lander on the Commodore PET” LOL. Been there, done that. But only during college hours.

First REAL game – Elite, on the BBC Micro

Search found 46 matches

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