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by Arjan
Tue Mar 08, 2016 9:23 pm
Forum: Bare metal, Assembly language
Topic: DMA and SPI
Replies: 2
Views: 1109

Re: DMA and SPI

joan wrote:I believe the current Linux driver spi_bcm2853 can use DMA to fill the hardware FIFOs.

If you actually want to use DMA to construct the SPI waveform then have a look at rawWaveAddSPI.
This is the bare metal forum. I am looking for a bare metal example.
by Arjan
Tue Mar 08, 2016 8:38 pm
Forum: Bare metal, Assembly language
Topic: DMA and SPI
Replies: 2
Views: 1109

DMA and SPI

Hi,

Is there sample code available for DMA and SPI?

I am mostly interested in SPI output.

Thanks, Arjan

https://github.com/vanvught/rpidmx512/t ... _responder
by Arjan
Mon Mar 07, 2016 3:28 pm
Forum: Bare metal, Assembly language
Topic: multiple timers on RPi2?
Replies: 5
Views: 3537

Re: multiple timers on RPi2?

The best option for precise timing is using IRQ's. The example below let the ACT blink at 1Hz. And other code is executed at 40 Hz. The definitions for BCM2835_ST can be found here https://github.com/vanvught/rpidmx512/blob/master/bcm2835-baremetal/include/bcm2835.h Hope this helps. Arjan http://www...
by Arjan
Sat Mar 05, 2016 12:00 pm
Forum: Bare metal, Assembly language
Topic: Vector table init at rpi2
Replies: 25
Views: 4951

Re: Vector table init at rpi2

xboot wrote:

Code: Select all

.arch_extension sec
.arch_extension virt
Thank you!
by Arjan
Fri Mar 04, 2016 8:40 pm
Forum: Bare metal, Assembly language
Topic: Vector table init at rpi2
Replies: 25
Views: 4951

Re: Vector table init at rpi2

But still can't catch the intention of this (why raw instructions?) .word 0xE12EF30E @ msr ELR_hyp, lr .word 0xE160006E @ eret The compiler does not recognize the msr and eret instructions. At least my (http://www.raspberrypi-dmx.com/raspberry-pi-dmx512-rdm/development-environment) version of the g...
by Arjan
Fri Mar 04, 2016 7:18 pm
Forum: Bare metal, Assembly language
Topic: Vector table init at rpi2
Replies: 25
Views: 4951

Re: Vector table init at rpi2

This startup code https://github.com/vanvught/rpidmx512/b ... /vectors.s
works on all Model 1's and Model 2 with latest firmware.

Not yet tested with Model 3.
by Arjan
Wed Mar 02, 2016 5:02 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 238748

Re: The Raspberry Pi 3 Model B Q&A thread

The UART on the GPIO header is now the mini-uart - a slight downside is that variations in core frequency change your baudrate. Forcing a fixed core clock works around this issue. Just to be sure that I am on the same page. Does this change means that the PL011 is not available anymore on external ...
by Arjan
Sun Feb 28, 2016 5:58 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Faster SPI
Replies: 24
Views: 8257

Re: Faster SPI

Hi cal-linux, I have ported the C library for Raspberry Pi (RPi) to bare-metal. This makes it easy to test your application in Linux, and run the same code on bare-metal (https://github.com/vanvught/rpidmx512/tree/master/bcm2835-baremetal). I have found SPI timing issue with the Model 2. See https:/...
by Arjan
Sun Feb 28, 2016 9:55 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 2 : SPI : Not reliable? (SOLVED)
Replies: 3
Views: 1235

Re: RPi 2 : SPI : Not reliable?

Hi Joan, I have set bcm2835_spi_setClockDivider((uint16_t) ((uint32_t) BCM2835_CORE_CLK_HZ / (uint32_t) 6400000)); and this results in a 6 MHz SPI clock. The timing for each byte varies a lot on the Model 2. It is working fine on the Model A+. Any pointers for what is happening here is much apprecia...
by Arjan
Sun Feb 28, 2016 9:13 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 2 : SPI : Not reliable? (SOLVED)
Replies: 3
Views: 1235

RPi 2 : SPI : Not reliable? (SOLVED)

Hi, Please see the two SPI timing diagrams for Model A+ and Model 2 with the same data. The Model A+ gives a nice SPI stream, where the stream for Model 2 has some gaps in the stream. The code below is running on bare-metal. Any thoughts why there a gaps in the SPI stream for the Model 2? Many thank...
by Arjan
Mon Feb 15, 2016 6:44 pm
Forum: General discussion
Topic: WS2801 and Pi
Replies: 3
Views: 1598

Re: WS2801 and Pi

See also here viewtopic.php?p=906699#p906699 for a "DMX to WS2801/WS2812/WS2812B Converter"
by Arjan
Mon Feb 15, 2016 6:42 pm
Forum: Other projects
Topic: DMX to WS2801/WS2812/WS2812B Converter
Replies: 2
Views: 2388

DMX to WS2801/WS2812/WS2812B Converter

Hi, The DMX to WS2801/WS2812/WS2812B converter is designed to convert the standard DMX512 signal into standard SPI signal to control LED light strips based on WS2801/WS2812/WS28B chips , or similar chips. A single DMX Universe has 512 channels, so it can drive max 170 RGB pixels ( 512/3 ). - Arjan R...
by Arjan
Wed Feb 03, 2016 5:00 pm
Forum: Other projects
Topic: Open source USB DMX-512 with RDM (Enttec USB Pro protocol)
Replies: 12
Views: 10104

PiZero: USB DMX-512 with RDM (Enttec USB Pro protocol)

PiZero : Open source USB DMX-512 with RDM (Enttec USB Pro protocol) Main features : *. Fully compatible with software suitable for ENTTEC USB Pro *. Compatible with OpenLighting rdmpro_sniffer (widget_mode=3) *. Suitable for testing RDM Reponders (OLA RDM Responder Tests) *. No external power supply...
by Arjan
Sun Jan 31, 2016 3:00 pm
Forum: Other projects
Topic: Open source USB DMX-512 with RDM (Enttec USB Pro protocol)
Replies: 12
Views: 10104

Re: Open source USB DMX-512 with RDM (Enttec USB Pro protoco

Hi Christophe, You can found the details here http://www.raspberrypi-dmx.com/raspberry-pi-rdm-controller/configuration and here http://www.raspberrypi-dmx.com/raspberry-pi-dmx512-rdm/install Please drop me a message when you encounter any issues. Thanks, Arjan Raspberry Pi Zero + DMX512 RDM isolated...
by Arjan
Tue Jul 14, 2015 7:54 pm
Forum: Bare metal, Assembly language
Topic: Bare Metal text mode acess
Replies: 2
Views: 1045

Re: Bare Metal text mode acess

by Arjan
Tue Jul 14, 2015 7:23 pm
Forum: Bare metal, Assembly language
Topic: Bare Metal "Hello Framebuffer World"
Replies: 5
Views: 2395

Re: Bare Metal "Hello Framebuffer World"

Not directly. You will need to write your own SD host + SD card + FAT filesystem driver, which can then enable access to the SD card. I have got a working example for SD host + SD card here : https://github.com/vanvught/rpidmx512/tree/master/emmc and FAT here : https://github.com/vanvught/rpidmx512...
by Arjan
Tue Jul 14, 2015 5:52 pm
Forum: Bare metal, Assembly language
Topic: Raspberry Pi 2 Mailbox
Replies: 2
Views: 1752

Re: Raspberry Pi 2 Mailbox

Hi, I have some mailbox examples here : *. https://github.com/vanvught/rpidmx512/blob/master/bcm2835-baremetal/src/bcm2835_mailbox.c *. https://github.com/vanvught/rpidmx512/blob/master/bcm2835-baremetal/src/bcm2835_vc.c *. https://github.com/vanvught/rpidmx512/blob/master/fb/src/console.c Hope this...
by Arjan
Sat Jul 04, 2015 11:01 am
Forum: Automation, sensing and robotics
Topic: DMX
Replies: 5
Views: 1481

Re: DMX

The easiest way is to get a USB to DMX adapter.
See latest append Open source USB DMX-512 with RDM and compatibility with software that supports Enttec USB Pro.
by Arjan
Sat Jul 04, 2015 10:53 am
Forum: Other projects
Topic: DMX controller
Replies: 3
Views: 8710

Re: DMX controller

Hi Martijn,

The DMX-512 / RDM interface for Raspberry pi is now available from here.

And you can find information about a Raspberry Pi RDM Responder (controlling SPI/I2C devices) here.

- Arjan
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by Arjan
Fri Jul 03, 2015 8:07 pm
Forum: Bare metal, Assembly language
Topic: RPI2 B+ OK LED
Replies: 20
Views: 6223

Re: RPI2 B+ OK LED

@Arjan, thanks for the links. Would you be able to explain why you take mod 32 of the pin number on this line https://github.com/vanvught/rpidmx512/b ... _led.c#L47 ? I assume it's the same reason that the Valver's bare metal tutorial uses 15 (example: https://github.com/Sheepzez/POS/blob/ma ... /r...
by Arjan
Fri Jul 03, 2015 3:38 pm
Forum: Other projects
Topic: Open source USB DMX-512 with RDM (Enttec USB Pro protocol)
Replies: 12
Views: 10104

Open source USB DMX-512 with RDM (Enttec USB Pro protocol)

Open source USB DMX-512 with RDM and compatibility with software that supports Enttec USB Pro. Main features : Raspberry Pi baremetal programming controls DMX512 timing Open source https://github.com/vanvught/rpidmx512/tree/master/rpi_dmx_usb_pro Supported operating systems: Windows, MAC OS, Linux U...
by Arjan
Fri Jul 03, 2015 3:23 pm
Forum: Bare metal, Assembly language
Topic: RPI2 B+ OK LED
Replies: 20
Views: 6223

Re: RPI2 B+ OK LED

Hi, I have some working code here : https://github.com/vanvught/rpidmx512/blob/master/bcm2835-baremetal/src/bcm2835_led.c And here https://github.com/vanvught/rpidmx512/blob/master/hal-baremetal/src/hardware.c#L199 a led init based on the RPi model. I hope this helps. Thanks, Arjan Looking for RPI D...
by Arjan
Mon Jun 08, 2015 2:22 pm
Forum: Other projects
Topic: DMX Lighting Controller
Replies: 19
Views: 19850

Re: DMX Lighting Controller

A DMX512 / RDM shield is available from http://www.bitwizard.nl/catalog/
There is also a version with USB (FT245RL). This shield is compatibility with software that supports Enttec USB Pro.

For more information, see https://sites.google.com/site/rpidmx512 ... dmx512-rdm
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by Arjan
Mon Jun 08, 2015 2:15 pm
Forum: General discussion
Topic: Raspberry as a DMX Device
Replies: 4
Views: 23948

Raspberry as a DMX Device

Hi, There is a Raspberry Pi DMX shield available from http://www.bitwizard.nl/catalog/ IMG.jpg Raspberry Pi open source DMX512 RDM solutions for the shield: Raspberry Pi DMX USB Pro (RDM Controller) Raspberry Pi RDM Responder (DMX Slave) Raspberry Pi DMX512 Receiver (Slave / Analyzer) Raspberyy Pi O...

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