System Timer access and GPIO does not work on my PI 2

[Yanxiang Mao]

Here is my code:

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <unistd.h>

#include <bcm2835.h> 

#include <inttypes.h>

int main(int argc, char* argv[])

{

uint64_t start, end;

if(!bcm2835_init())

return 1;

// Read start time

start = bcm2835_st_read();

// Call sleep(1) 10 times decrease the error

sleep(1);

// Read end time

end = bcm2835_st_read();

// Print result

printf("time = %llu uS\n", (end-start)/(10));

bcm2835_close();

return 0;

}

The out put is 0 us.

And I have a another question, where I can find RPiGPIOPin for PI 2?

[Mike McCauley]

What do you see on RPi 1?

> <http://www.airspayce.com/mikem/bcm2835/group__constants.html#ga63c029bd6500
> 167152db4e57736d0939> for PI 2?

--
Mike McCauley VK4AMM mi...@airspayce.com
Airspayce Pty Ltd 9 Bulbul Place Currumbin Waters QLD 4223 Australia
http://www.airspayce.com
Phone +61 7 5598-7474

[Yanxiang Mao]

Around 1000200 us on RPi B.

在 2015年3月30日星期一 UTC+8上午9:27:49，Mike McCauley写道：

[Mike McCauley]

And what OS and version are you using?

[lanlongzhiwang]

On RPi 2, OS is 3.18.10-v7, bcm2835 library is 1.43. I tried 1.39 to 1.43 not even one got work.

---

发件人: Mike McCauley
发送时间: ‎3/‎30/‎2015 12:33 AM
收件人: bcm...@googlegroups.com
主题: Re: [bcm2835] System Timer access and GPIO does not work on my PI 2

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[Mike McCauley]

And what distribution is that? Raspbian? What date?

On Monday, March 30, 2015 01:48:01 AM lanlongzhiwang wrote:
> On RPi 2, OS is 3.18.10-v7, bcm2835 library is 1.43. I tried 1.39 to 1.43
> not even one got work.
>

> -----原始邮件-----
> 发件人: "Mike McCauley" <mi...@airspayce.com>

> 发送时间: ‎3/‎30/‎2015 12:33 AM

> 收件人: "bcm...@googlegroups.com" <bcm...@googlegroups.com>

[Mike McCauley]

For RPi 2 you MUST use the latest version of bcm2835 (version 1.43) AND the
latest version of the RPI software. Check whether /proc/device-tree/soc/ranges
exists on your OS. It needs to be there for bcm2835 to work on RPi2


Cheers.

On Monday, March 30, 2015 01:48:01 AM lanlongzhiwang wrote:

> On RPi 2, OS is 3.18.10-v7, bcm2835 library is 1.43. I tried 1.39 to 1.43
> not even one got work.
>

> -----原始邮件-----
> 发件人: "Mike McCauley" <mi...@airspayce.com>

> 发送时间: ‎3/‎30/‎2015 12:33 AM

> 收件人: "bcm...@googlegroups.com" <bcm...@googlegroups.com>

[Yanxiang Mao]

2015-02-16-raspbian-wheezy

在 2015年3月30日星期一 UTC+8下午7:43:06，Mike McCauley写道：

[Yanxiang Mao]

I dont know what wrong with my RPI 2, there is no /device-tree under /proc.

在 2015年3月30日星期一 UTC+8下午7:43:06，Mike McCauley写道：

For RPi 2 you MUST use the latest version of bcm2835 (version 1.43) AND the

[Manuel Hecht]

Hello

I had the same problem. Here is the solution to enable device tree support. (special thanks to Mark)

sudo raspi-config
under Advanced Options - enable Device Tree
under Advanced Options - disable SPI
Reboot and it should hopefully work.

Regards

Manuel

[Yanxiang Mao]

Thank you for help. But still does not work, I may try to reinstall my OS.

在 2015年3月30日星期一 UTC+8下午11:19:40，Manuel Hecht写道：

[Mike McCauley]

Im quite sure you will find that if you have the latest debian, with device
tree enabled it will work:

tested here today:

pi@raspberrypi ~/bcm2835-1.43 $ gcc -o x -I src src/bcm2835.c x.c
pi@raspberrypi ~/bcm2835-1.43 $ sudo ./x
time = 100015 uS
pi@raspberrypi ~/bcm2835-1.43 $

Cheers.

[Yanxiang Mao]

I use a new SD card install the same image, it is work. Thank you all for help.

在 2015年3月31日星期二 UTC+8上午7:07:34，Mike McCauley写道：