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by adun
Wed Dec 02, 2015 7:38 am
Forum: HATs and other add-ons
Topic: Miscap - PiZero Ethernet pHAT
Replies: 86
Views: 22509

Re: PiZero Ethernet pHAT

Very nice work :)
Can't wait to start testing it.

I would call it Audio-Lan HAT or ZeroHAT.
by adun
Tue Dec 01, 2015 2:47 pm
Forum: HATs and other add-ons
Topic: Miscap - PiZero Ethernet pHAT
Replies: 86
Views: 22509

Re: PiZero Ethernet pHAT

I think there could still be a need for the Ethernet pHAT as people want to keep the USB port free. And there could be problems about USB drivers with so cheap devices. The Eth pHAT would also fit better in a enclosure... PS: Or we could start a new project: A HAT like expansion board for the Zero t...
by adun
Mon Nov 30, 2015 9:46 pm
Forum: HATs and other add-ons
Topic: Miscap - PiZero Ethernet pHAT
Replies: 86
Views: 22509

Re: PiZero Ethernet pHAT

I just had a similar idea and found your post ;) I also need SPI0 free and was looking to implement a ENC28J60 on SPI1. What i found about SPI1 is: Not many. It's more limited than SPI0, though. - The SPI1 clock is derived from the system clock therefore you have to be careful when over/underclockin...
by adun
Mon Nov 30, 2015 12:22 pm
Forum: Astro Pi
Topic: SOLVED.Sense HAT 40-pin layout?
Replies: 7
Views: 3843

Re: SOLVED.Sense HAT 40-pin layout?

I have a similar question.
As I see the Sense HAT is using SPI0 with CE0_N for the AVR update.

If I want to connect another SPI device,
is it save to use SPI0 with the two chip select during attached Sense HAT or will this clash?
by adun
Thu Oct 29, 2015 9:55 pm
Forum: Astro Pi
Topic: What is the 2x20 pin black connector block on Sense HAT?
Replies: 10
Views: 5582

Re: What is the 2x20 pin black connector block on Sense HAT?

I use a few different configurations, & rather than modify the sense-hat, I use a female to male ribbon cable extension. I built one of the vga666 adapters with longer pins so that I could accommodate further boards, or sockets, as in the attached picture. How did you get VGA and the Sense HAT work...
by adun
Sun Oct 18, 2015 2:05 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: USB slave <-> serial conector chip
Replies: 6
Views: 1790

Re: USB slave <-> serial conector chip

What about an Atmega32u4 from Atmel? It can act as a USB Slave and has an UART port that you can connect to the RPi. The same chip is used in the Arduino Leonardo if you want start prototyping. Or the Atmega16u2 which is used in the Arduino UNO as the USB-Serial bridge. If you only need a UART to US...
by adun
Mon Sep 07, 2015 10:11 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: 1 to 2 UART Switch/Mux ?
Replies: 3
Views: 1955

Re: 1 to 2 UART Switch/Mux ?

Thanks a lot for your help :) . So I will try to use some 74HC157s you mentioned
by adun
Fri Sep 04, 2015 5:29 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: 1 to 2 UART Switch/Mux ?
Replies: 3
Views: 1955

1 to 2 UART Switch/Mux ?

For an experiment I need to connect 2 uart devices to the RPi uart port and swich the connection by jumper or GPIO.
Flow controll RTC, CTS is needed.
So I need a 2 to 1 four port switch/multiplexer. Does anybody know a dedicated switch or mux chip that I can use?

Thanks in advance
by adun
Fri Jul 24, 2015 7:02 pm
Forum: HATs and other add-ons
Topic: GPIO RAM MODULE
Replies: 20
Views: 7093

Re: GPIO RAM MODULE

Nice informations :) And yes, the SMI can use the same pins as DPI . However there are still missing informations about DPI, but I assume that the DPI pins can also be moved like the SMI pins. On the BCM2835 GPIO map there are a lot of ALT functions marked as "<reserved>" which could stand for the D...
by adun
Fri Jul 24, 2015 5:02 pm
Forum: HATs and other add-ons
Topic: GPIO RAM MODULE
Replies: 20
Views: 7093

Re: GPIO RAM MODULE

Just for the sake of completeness: I found a product brief of the BCM 2722 processor that seems to have similar interfaces like the BCM 2835. http://curiouscat.org/Steve/Media/2722-PB01-R.pdf There is also a Secondary Memory Interface: Secondary memory interface (e.g., for connection to memory- mapp...
by adun
Fri Jul 24, 2015 4:43 pm
Forum: Compute Module
Topic: Raspberry Pi 2 Compute Module?
Replies: 9
Views: 4634

Re: Raspberry Pi 2 Compute Module?

If there is something like a wishlist for the Compute Module 2 it would be very nice if we could have the following improvements :) Access to the pins of the Host Interface : Would allow us to have a 8/16-bit data bus. Access to GPIO 48-53 (SD0) . To be able to exchange/expand the onboard eMMC The a...
by adun
Sat Jul 04, 2015 3:24 pm
Forum: HATs and other add-ons
Topic: GPIO RAM MODULE
Replies: 20
Views: 7093

Re: GPIO RAM MODULE

I understand. Thank anyway for your information.
Lets hope Broadcom will release the missing docs in the foreseeable future
by adun
Fri Jul 03, 2015 10:54 pm
Forum: HATs and other add-ons
Topic: Using I2C devices on a HAT
Replies: 2
Views: 1532

Re: Using I2C devices on a HAT

The i2c0 bus is usually used by the firmware and the GPU takes control of the i2c0 bus. You should be able to connect a HAT EEPROM and a camera module to the same port as they have different addresses. But you can't use that interface by the ARM at the same time. I had a similiar thread about that a...
by adun
Fri Jul 03, 2015 10:44 pm
Forum: HATs and other add-ons
Topic: GPIO RAM MODULE
Replies: 20
Views: 7093

Re: GPIO RAM MODULE

And yes, you can use the GPIO as SMI but you will gain very little as the amount of memory you can connect is minuscule and slow. I can't remember the details but I think you can connect up to 128K bytes. So you can add another 0.01% memory.... It would be nice to know what type of memory the SMI i...
by adun
Wed Apr 29, 2015 10:50 am
Forum: Compute Module
Topic: BCM2835 boot modes and BIOS chip
Replies: 7
Views: 4025

Re: BCM2835 boot modes and BIOS chip

Thanks for the replies. I already know berrryboot. But berryboot is like noobs. It needs a pre flashed SD card. I think I will try to play around with the I2C/SPI Slave Interface. My thought was to send bootcode (bootcode.bin etc) from a ATmega328P to the BCM2835. Are there more informations about t...
by adun
Mon Apr 27, 2015 2:23 am
Forum: Compute Module
Topic: BCM2835 boot modes and BIOS chip
Replies: 7
Views: 4025

BCM2835 boot modes and BIOS chip

I would like to pick up an idea that mahjongg postet in this thread about a possible BIOS chip implementation: actually, but this is an educated guess, as I don't know exactly how the SD-card is addressed during booting, but IF it happens to use the simple SPI mode (which all SD-Cards support, as a ...
by adun
Thu Apr 23, 2015 1:01 pm
Forum: General discussion
Topic: booting only from USB - in future - (USB-on-the-go)
Replies: 45
Views: 8829

Re: booting only from USB - in future - (USB-on-the-go)

actually, but this is an educated guess, as I don't know exactly how the SD-card is addressed during booting, but IF it happens to use the simple SPI mode (which all SD-Cards support, as a baseline communications mode), then there could be a way to provide a PI with an extended boot mechanism. Its ...
by adun
Tue Mar 24, 2015 5:47 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

Ok thanks for the reply :)
The HAT and VGA are not really needed I just try as an extra to make it B+ compatible.
As the HATs are not probed by default on CM this will solve most of the configuration problems. I will only have to set the GPIO modes manually if needed.
by adun
Tue Mar 24, 2015 5:32 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

I thought about a other solution using an i2c mux: GPIO 2,3 and 44,45 are connected to an i2c mux that leads to all i2c devices. By default i2c1 is activated on GPIO pins 44,45 and they are selected by the mux. The selection is controlled by a little skript that checks if the GPIO 2,3 mode is set to...
by adun
Tue Mar 24, 2015 3:43 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

The reason is that if a HAT (or the VGA 666) is using GPIO 2,3 for something other than i2c1 I have no longer access to the other devices.
An i2c mux is probably another option I will think about.
by adun
Tue Mar 24, 2015 2:49 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

I have another question concerning i2c1 . As I have mentioned above I have other devices (RTC, sensors) permanently connected to the i2c1 bus on GPIO 44,45. If now there is a HAT conected that uses i2c1 on GPIO 2,3 1) Will there be any trouble if the HAT activates i2c1 on GPIO 2,3 during i2c1 on GPI...
by adun
Fri Mar 20, 2015 9:30 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

Ok, that is what I assumed. As I have other devices connected to i2c1 used by ARM, I will keep both cams on i2c0.
Thanks for the good explanation.
by adun
Fri Mar 20, 2015 8:33 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

Thanks for the information
And if I use i2c1 on GPIO 44,45 for de second camera ?
by adun
Fri Mar 20, 2015 7:30 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

Ok thanks a lot.
Just one more question. Connecting both cameras to the same i2c0 pins (28,29) is not possible?
Because it would be nice to keep both cams enabled even if I use GPIO 0,1 with DPI for example
by adun
Fri Mar 20, 2015 6:50 pm
Forum: Compute Module
Topic: i2c0 dual camera and HAT eeproms
Replies: 24
Views: 3675

Re: i2c0 dual camera and HAT eeproms

I thought that on B+ the CAM is connected through i2c0 on GPIO 28,29
and that during boot the firmware first looks at GPIO 0,1 for an EEPROM and then switch the i2c0 to GPIO 28,29. As i2c0 can't be enabled on both 0,1 and 28,29 at the same time.
Correct me if I'm wrong

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