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by w4mmp
Sun May 17, 2020 3:32 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Modify i2c bus
Replies: 8
Views: 437

Re: Modify i2c bus

on my rpi4 after enabling i2c via `raspi-config`, i'm only seeing one adapter (just as an example) That is because you have not enabled another i2c buss. By default only i2c-1 is enabled. In config.txt you need to add: dtoverlay=i2c6 or whatever ic2 buss you want to use. Forget the custom pin stuff....
by w4mmp
Sun May 17, 2020 2:49 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Modify i2c bus
Replies: 8
Views: 437

Re: Modify i2c bus

Hello, I'm not very sure I understand what you are attempting to do, but there is no I2C-7 available on the Pi 4B. There is only 1 through 6. How i2cdetect is finding I2C 7, I don't have a clue. I don't know Python but that error "[Errno 121] Remote I/O error" is what is return by the operating syst...
by w4mmp
Sat Apr 25, 2020 12:21 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Is there anyway to connect more than 4 ADS1115's to a raspberry pi?
Replies: 2
Views: 265

Re: Is there anyway to connect more than 4 ADS1115's to a raspberry pi?

Is this a Raspberry PI 4? (or not?). If it is the RPi 4, then there are four sets of pins that may be used as I2C buses. We have a project where I2C-1 and I2C-6 are used. An alternative is to use an I2C multiplexer such as this: TCA9548A I2C Multiplexer (https://www.adafruit.com/product/2717). Regar...
by w4mmp
Sat Apr 18, 2020 2:59 pm
Forum: Raspberry Pi OS
Topic: Legal Question
Replies: 1
Views: 176

Legal Question

Hello, I am working on a product that incorporates Raspberry Pi 4B into the product. The product will be for sale. I would like to supply a pre-configured micro SD card that includes our custom application and Raspbian. My question is: Is it legal to sell the micro SD that has Raspbian included? I d...
by w4mmp
Tue Mar 24, 2020 6:29 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Understanding i2cdump options
Replies: 2
Views: 293

Re: Understanding i2cdump options

Hello, The first question I have is: Does your I2C device have addressable registers? If not then the only i2c tool that will function correctly is i2ctransfer. i2ctransfer is the only tool that does NOT immediately issue a stop when the operation is complete. The i2ctransfer uses an ioctl call with...
by w4mmp
Sat Mar 07, 2020 5:03 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Folks, Finial note on my efforts. PIGPIO and the bcm2835 (C library) are both a no go. However, the i2c tools (i2cget, i2cset, etc.) work fine. I am able to access the test i2c device and set and get register values without hosing the audio hat. I the i2c tools source is fairly easy to follow so I w...
by w4mmp
Fri Mar 06, 2020 4:06 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Hi Joan,
I'm sorry but I don't really understand that. Would you provide a bit more information?
by w4mmp
Fri Mar 06, 2020 2:29 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Just for a bit more information below is an RPi 4B pin out diagram with the audio hat pin out overlay we are using for hardware development.
overlay-3.jpg
overlay-3.jpg (127.71 KiB) Viewed 1055 times
by w4mmp
Fri Mar 06, 2020 2:23 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Hi, Just a quick update. The audio hat and an i2c device are now both installed on the RPi 4B. According to the very sparse documentation for the hat it uses i2c buss 1. I2cdetect confirms it is on buss 1 and reports UU at address 0x1A. The i2c device is on buss 6 and i2cdetect confirms is on buss 6...
by w4mmp
Tue Mar 03, 2020 5:51 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Hi, Thanks for the info. I am however able to have the audio hat and the I2C device(s) we are implementing work on separate I2C buses in so far that i2dectect -y 1 shows the audio hat on buss #1 and i2cdected -y -6 shows the I2C device on buss #6. I think this configuration will work. Now the challe...
by w4mmp
Tue Mar 03, 2020 2:46 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Hi Matt, Thanks for taking the time to review this thread. I may be wrong, but I believe it is not possible to have two applications accessing the same I2C buss at the same time. As mentioned, the audio hat needs access to the primary I2C buss. If my application also accesses the same I2C buss there...
by w4mmp
Wed Jan 22, 2020 6:26 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Hi, I will give pigpio a go first and see what happens with the audio hat. The hat uses dtoverlay=audioinjector-wm8731-audio. There might be just a touch of confusion (due to my confusion). We will not be accessing the audio hat directly. The application accesses the hat via Port Audio using the ALS...
by w4mmp
Wed Jan 22, 2020 4:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

Re: RPi 4 - Using alternate I2C

Hi Dave, Thanks so much! Yes, adding dtoverlay=i2c5 to config.txt activated the i2c 5 buss. I2cdetect finds and reports the connected devices. Now to find an I2C library that handles buses other than the primary buss. I normally use an easy to use and well documented library offered by http://www.ai...
by w4mmp
Tue Jan 21, 2020 4:47 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi 4 - Using alternate I2C
Replies: 14
Views: 1595

RPi 4 - Using alternate I2C

Hello, Background. We are working on a project that incorporates a Audio-Injector hat. Among the pins it uses are the primary I2C pins. However we also have other I2C devices we need to access. So the question is, may the RPi 4 have two active I2C buses? We were hoping to use the pins that may be us...
by w4mmp
Sun Apr 24, 2016 6:34 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C to 16x2 LCD converter - voltage and RPi connection.
Replies: 19
Views: 9427

Re: I2C to 16x2 LCD converter - voltage and RPi connection.

Hi, Yes, you are absolutely correct. I can live with it for now as the final destination of the display is for different device. I use the RPi 2 for code development and initial testing. The code developed on the RPi 2 is about 80 to 90% portable to the final device (Cypress PSoC 5). Just much easy ...
by w4mmp
Sun Apr 24, 2016 2:57 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C to 16x2 LCD converter - voltage and RPi connection.
Replies: 19
Views: 9427

Re: I2C to 16x2 LCD converter - voltage and RPi connection.

Hi, In the "for what its worth" category. Attached is source code that will drive a LCD1602 display commonly available on the internet. The source is from http://wiki.friendlyarm.com/wiki/index.php/Matrix_-_I2C_LCD1602 and has been modified to use Mike McCauley's BCM 2835 library located here: http:...
by w4mmp
Thu Sep 03, 2015 8:53 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Disc Activity LED
Replies: 7
Views: 1338

Re: Disc Activity LED

rpdom wrote:I don't think there is an easy way of using the on-board LED and another GPIO at the same time.
Ok, thanks. I just had to ask ;)
by w4mmp
Thu Sep 03, 2015 7:32 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Disc Activity LED
Replies: 7
Views: 1338

Re: Disc Activity LED

May a GPIO pin be used and may the part of the O.S. that flashes the on board LED be re-directed to the GPIO pin? Yes. Easily. Add the following to /boot/config.txt dtparam=act_led_gpio=XX where "XX" is the BCM GPIO number for the pin you want to use. Ok, I suppose this comes under the category of ...
by w4mmp
Mon Aug 31, 2015 4:08 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Disc Activity LED
Replies: 7
Views: 1338

Re: Disc Activity LED

Use a fibre optic bundle. It's easier than trying to wire your own LED. Hi, All the GPIO pins will be attached to a "multiplexer" board which will serve multiple purposes within the design of the project. So, connecting a LED to the multiplexer will not be a big deal. But thanks for you suggestion.
by w4mmp
Mon Aug 31, 2015 3:58 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Disc Activity LED
Replies: 7
Views: 1338

Re: Disc Activity LED

Excellent !

Thanks so much for getting back with me so quickly.
by w4mmp
Mon Aug 31, 2015 3:03 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Disc Activity LED
Replies: 7
Views: 1338

Disc Activity LED

Hi, I am working on a Amateur radio project that includes the RPi 2. The RPi 2 will tucked away in a case and not visible. I would like to have a LED attached to the RPI 2 and visible on the case panel just so that the user can see disc activity. May a GPIO pin be used and may the part of the O.S. t...
by w4mmp
Sun Aug 23, 2015 2:40 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO Security
Replies: 28
Views: 7379

Re: GPIO Security

Thanks much for the information. I am reading it now.
by w4mmp
Sun Aug 23, 2015 1:22 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO Security
Replies: 28
Views: 7379

Re: GPIO Security

Hi, The question generated a bit of interest ;) But the discussion is way over my head. As just a user of a GPIO library (most likely any GPIO library), what do I do to allow my application to run as something other than root. Is it possible? If so, please bear with me, and provide exactly what I ne...
by w4mmp
Sat Aug 22, 2015 8:42 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO Security
Replies: 28
Views: 7379

Re: GPIO Security

B.Goode wrote:For example: http://abyz.co.uk/rpi/pigpio/

(The author/maintainer, @joan, is a frequent contributor to these forums.)
Hi,
Thanks. I took a look at the library. Interesting idea of having a server run as root and handle user GPIO requests through that server.
by w4mmp
Sat Aug 22, 2015 6:05 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO Security
Replies: 28
Views: 7379

GPIO Security

Hi, I use a GPIO library (http://www.airspayce.com/mikem/bcm2835/) which works quite well. The question I have is there a way to secure the GPIO hardware (pins, what have you) so that the applications do not need to run as root? Is there a udev configuration that may be created (or something along t...

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