Raspberry Pi Forums

StuartF

I'm wondering where the CODE: was SELECT from....

StuartF

Thanks for the replys @topguy ironically i had to sudo usermod -a -G render pi but that did nothing. @Daniel Gessel Looking at kmscube, it seems to be GL2, and have 'legacy' fallback. I'm running the latest buster, so it might be different. So a new day, from a fresh boot, I ran the program without ...

StuartF

I am currently updating a program using openGL2 using dispmanx from the pi3 to openGL3 using DRM. Everything was going generally ok, until I hit a brick wall. The problem was gbm_surface_lock_front_buffer always returning NULL after eglSwapBuffers. So after going through the code and checking all th...

StuartF

The idea was to put an eraser diameter neo magnet on each corner of the flats with a matching (inverted) magnet on the frame. If you want to reduce the chance of magnetic interference on the pi case, use small steel strips instead of magnets on the case. Keep the magnets on the mounting area. If yo...

StuartF

Could it be the HDMI cable?
I had the same problem using an adaptor and existing cables I had used for PI1,2 & 3.
These were HDMI spec 1.0 and spec 1.3.
I got a HDMI 2.0, which is 4K compatible, and the problem was resolved.

StuartF

There are two check_button() functions being defined.
One is empty, just above 'void lcdcmd(unsigned int ch)'.

This may be the cause of the problem, however try using gdb to debug.

StuartF

B is Linear
A is Log

StuartF

Start with

help> documentation > hardware > raspberrypi > bcm2835

and look at 'Peripheral specification' pdf.
Also refer to the errata as there are some errors in the PWM section.

StuartF

SPI is a duplex operation. As you write data out on MOSI signal, data can come in on the MISO signal from the slave device. This TX & RX is using the same CLK. This CLK is generated by the master. To kick a slave into transmitting, you have to generate the CLK. This is done by 'writing' to the F...

StuartF

There is a problem in your initMapMem function. The second mmap() parameter is the page size for the map. You are passing 0x84 (132 ) as the value. This should be 4096. This is a fixed value, so you could use a constant, but you don't need to pass it. e.g. static uint32_t * initMapMem(int fd, uint32...

StuartF

It could be that the LAN chip is faulty. Does it get hot?

Are you connecting USB devices directly into the pi or through a USB hub?

Does the yellow led come on if you connect the network cable?

StuartF

Midi out does not require opto-isolation, only midi in.
So a transistor or mofet acting as a switch will do the conversion.

StuartF

So DIVI = 177 and DIVF = 0.1541195011 * 1024 = 157.8183... I "rounded" it at 158.

This is incorrect. This should be 4096. Although it says 1024 in the PCMCLK datasheet, it has been corrected
in the forums and is mentioned in the example source code.

StuartF

I'll reply in this thread as it is more relevant. From the other thread.. I set MASH 1 , DIVI = 177 , DIVF = 158 This is for 44100 @ 32 bit stereo? You have the correct DIVI, but the DIVF is not correct. How are you working DIVF out? By my calc, DIVF should be 681 ( although it falls on an edge case...

StuartF

Depending on which i/o you are using as an input, it could be an internal pull-up is active.
This would act as a voltage divider.
Try to get it working with just one Pi first, then add the others once debugged.

StuartF

But the WS0010 controller is not 100% compatible with the HD44780 It is compatible, but the "usual practice" of wiring the LCD module to be write only causes the problems with this chipset. I have not looked into the I2C_LCD_driver module, but it may have a read function. Failing that, as...

StuartF

I have had experience of this chipset. There is a small but critical difference. To quote from the datasheet BUSY FLAG (BF) The Busy Flag is used to determine whether WS0010 is idle or internally operating. When WS0010 is performing some internal operations, the Busy Flag is set to "1". Un...

StuartF

They are cmos 256K x 4bit dynamic ram.
The datasheet is out there, you may want to try another search engine ( that doesn't track you). Search for '514256 datasheet'.

StuartF

There is a return NULL in the adc function that may be causing the problem. Also, when you check for fp == NULL, it may be wise to use an else condition for the output. e.g. if( fp == NULL ) { <fail message> } else { <write to fp> <close fp> } Another suggestion would be to have the thread function ...

StuartF

In your spiTransfer function, try adding

Code: Select all

.cs_change = 0
.pad = 0

to struct spi_ioc_transfer tr .

StuartF

You have an out of date dt-blob.dts
Try
https://github.com/raspberrypi/firmware ... t-blob.dts

StuartF

You will need to set the termios options.

Code: Select all

tcsetattr( fd, TCSANOW, &options );

StuartF

You seem to be missing a few settings in the rpi code. Add these global vars uint8_t bitsPerWord = 8; uint8_t spiMode = SPI_MODE_0; In main() add ioctl( fd, SPI_IOC_WR_MODE, &spiMode ); ioctl( fd, SPI_IOC_WR_BITS_PER_WORD, &bitsPerWord ); In your atmega code you pause 10ms (milli). In your r...

StuartF

Sorry about that.

Code: Select all

#define BLOCK_SIZE		4096

StuartF

This has worked for me using the standard bcm2709.uart_clock=3000000 clock setting in cmdline.txt with the ttyAMA0 default removed. It uses mmap to directly set the PL011 registers according to the ARM datasheet. The datasheet can be found here. http://infocenter.arm.com/help/topic/com.arm.doc.ddi01...

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