Yes this is the base address for the Pi 4
Search found 20 matches
- Wed Sep 18, 2019 12:55 pm
- Forum: Bare metal, Assembly language
- Topic: mmap() fails
- Replies: 9
- Views: 2437
- Wed Sep 18, 2019 12:54 pm
- Forum: Bare metal, Assembly language
- Topic: mmap() fails
- Replies: 9
- Views: 2437
Re: mmap() fails
The problem occurred before that code the file did not open it told you Unable to open /dev/mem The illegal argument is the file handle. Ok I see what you are saying but /dev/mem is successfully opened by a preceding open() statement as so: memfd = fd; if (fd < 0) { printf("mapmem: file descriptor ...
- Tue Sep 17, 2019 5:55 pm
- Forum: Bare metal, Assembly language
- Topic: mmap() fails
- Replies: 9
- Views: 2437
- Tue Sep 17, 2019 5:21 pm
- Forum: Bare metal, Assembly language
- Topic: mmap() fails
- Replies: 9
- Views: 2437
mmap() fails
Hello, I am trying to access /dev/mem using a nodejs module. I am aware this takes root access. I have asked this question elsewhere but I am refocusing the question on this forum, as The nodejs module uses a C program which is its interface to the hardware. The low level C program can be compile an...
- Thu Sep 12, 2019 4:31 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
Re: Problems with Pi 4 Wiring Pi4 GPIO
So to sum it up, mmap() is failing when called from node js rpio. But not when the C code is complied and run on its own. The error says Invalid argument but all parameters are check (and displayed in latest debug). I am playing with the parameters however. I suspect a the file descriptor was/is bad...
- Thu Sep 12, 2019 4:11 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
- Tue Sep 10, 2019 12:29 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
- Mon Sep 09, 2019 9:03 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
Re: Problems with Pi 4 Wiring Pi4 GPIO
The code I linked uses /dev/mem and works on all Pis. My C code does not fail either. The problem is when The C code is called from a Javascript (nodejs) program mmap() fails. Which is very odd because C doesn't know how its called. The only difference in the calls that I can see are that the file ...
- Mon Sep 09, 2019 8:15 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
Re: Problems with Pi 4 Wiring Pi4 GPIO
For what it is worth have a look at http://abyz.me.uk/rpi/pigpio/examples.html#Misc_minimal_gpio Thanks. The particular difficulty I am having requires access to the /dev/mem device. /dev/gpio won't do. the /dev/mem device requires root access btw. My main difficulty seems to be calling mmap() corr...
- Mon Sep 09, 2019 6:31 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
Re: Problems with Pi 4 Wiring Pi4 GPIO
The size of hex 1800000 seems suspicious. I tend to just map individual peripherals and the few bytes they need. I meant does the code work on the Pi3 with the correct offset. Understood, regard the your approach to map what you need. I am in the process of upgrading some code to the Pi 4 for the P...
- Mon Sep 09, 2019 5:21 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
Re: Problems with Pi 4 Wiring Pi4 GPIO
The size of hex 1800000 seems suspicious. I tend to just map individual peripherals and the few bytes they need. I meant does the code work on the Pi3 with the correct offset. Yes it does work with the correct offset. Please note, This also work when opening /dev/gpiomem. It is the mmap() function ...
- Mon Sep 09, 2019 3:42 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
- Mon Sep 09, 2019 3:00 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 13
- Views: 631
Problems with Pi 4 Wiring Pi4 GPIO
I am writing code to access /dev/mem on the raspberry pi 4. I'm using nodejs with the package rpio. Rpio uses a "C" language interface. I have modified the *.h file to reflect changes in the hardware address for pi3 to pi4. like so: #define BCM2711_RPI4_PERI_BASE 0xFE000000 I am aware that root perm...
- Wed Aug 28, 2019 3:07 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 14
- Views: 3145
Re: Problems with Pi 4 Wiring Pi4 GPIO
Thanksjoan wrote: ↑Tue Aug 27, 2019 9:07 pmIn that case there is either a wiring problem or 18 is not referring to the GPIO you think it is.
https://pinout.xyz/
- Wed Aug 28, 2019 2:57 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 14
- Views: 3145
Re: Problems with Pi 4 Wiring Pi4 GPIO
Thanks people. I Think I have solved the problem 
. The Key was the gpio readall which mapped WiringPI pin number to GPIO pin numbers. I am still having problems associating the GPIO pin number to the actual address of the pin register.
. The Key was the gpio readall which mapped WiringPI pin number to GPIO pin numbers. I am still having problems associating the GPIO pin number to the actual address of the pin register.- Wed Aug 28, 2019 2:54 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 14
- Views: 3145
Re: Problems with Pi 4 Wiring Pi4 GPIO
Not in any way an answer to your question, but before you expend a lot of effort to get it running are you aware that the sole developer/maintainer of WiringPi has recently announced that he is no longer developing or supporting it and has recommended seeking an alternative: I will make a final rel...
- Tue Aug 27, 2019 9:05 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 14
- Views: 3145
Re: Problems with Pi 4 Wiring Pi4 GPIO
Just to confirm that you're using an up to date version of wiringPi what does gpio -v and gpio readall report? (Compare with that here: http://www.cpmspectrepi.uk/raspberry_pi/MoinMoinExport/WiringPiGpioReadall.html#Pi_4_B) Trev. pi@raspberrypi:~ $ gpio -v gpio version: 2.52 Copyright (c) 2012-2018...
- Tue Aug 27, 2019 8:59 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 14
- Views: 3145
Re: Problems with Pi 4 Wiring Pi4 GPIO
joan wrote: ↑Tue Aug 27, 2019 8:44 pmHave you downloaded the latest version?
Yes I am up to date.
http://wiringpi.com/wiringpi-updated-to ... rry-pi-4b/
- Tue Aug 27, 2019 8:36 pm
- Forum: Troubleshooting
- Topic: Problems with Pi 4 Wiring Pi4 GPIO
- Replies: 14
- Views: 3145
Problems with Pi 4 Wiring Pi4 GPIO
Hello: I am trying to toggle a LED mapped to GPIO. My code does not working and I have been working on a reason why. I'm thinking this may have something to do with the GPIO base address being changed on the Pi 4. Here is my (non-working) code: #include <wiringPi.h> int main (void) { wiringPiSetup (...
- Thu Apr 04, 2019 8:31 pm
- Forum: Ubuntu
- Topic: Error reducing rootfs partition size (ubuntu)
- Replies: 0
- Views: 2415
Error reducing rootfs partition size (ubuntu)
Hello: I am using Ubuntu Linux. I am trying to resize the partition /dev/sdb2 labled rootfs. Currently the partition size is 7.36 and the used size is 4.84GB. I am trying to reduce the size of Raspbian named the second partition labelled rootfs. I have tried to resize using gparted, which fails gpar...