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by mbt28
Thu Apr 11, 2019 11:27 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: 16 Bit PWM Mono Audio
Replies: 0
Views: 145

16 Bit PWM Mono Audio

Hello, I need a mono audio output from RPI to use it for handsfree speaker purposes. I cannot use I2S because it is dedicated for other usage. While I was searching on internet I saw that you can use multiple PWMs to create higher resolution. Since I dont need a stereo I would like combine PWM1 and ...
by mbt28
Thu Dec 13, 2018 11:50 am
Forum: Device Tree
Topic: DSI Device Tree Entries - module probe not being called
Replies: 12
Views: 3715

Re: DSI Device Tree Entries - module probe not being called

I pulled them up to the Vcore pin on the interface chip (pin 31), as I think that is the internal supply for the DSI line receivers. It worked for me. As you say, it is unclear why this should be necessary, but it appears to be. Hi Chris, If I change 1.8V to Vcore supply the schematic that I attach...
by mbt28
Thu Dec 13, 2018 11:13 am
Forum: Device Tree
Topic: DSI Device Tree Entries - module probe not being called
Replies: 12
Views: 3715

Re: DSI Device Tree Entries - module probe not being called

Chris_G_Miller wrote:
Wed Dec 12, 2018 9:44 pm
Just the clock lines, not the data lanes
Hi,

Is it okay as attached? As I know DSI clock uses 1.2V level, is okay to use 1.8V?

Thanks
by mbt28
Wed Dec 12, 2018 8:29 pm
Forum: Device Tree
Topic: DSI Device Tree Entries - module probe not being called
Replies: 12
Views: 3715

Re: DSI Device Tree Entries - module probe not being called

Yes, it all works - but take note of my need to provide some DC bias on the DSI clock lines in my post (2k pullup on each wire) - did not have to mess with the Data lanes. I have now revised my design to use the I2C interface chip you managed to find, and it works a treat. I will shortly be re-visi...
by mbt28
Wed Dec 12, 2018 5:06 pm
Forum: Device Tree
Topic: DSI Device Tree Entries - module probe not being called
Replies: 12
Views: 3715

Re: DSI Device Tree Entries - module probe not being called

Yes - I have managed to make it work in that I can get a picture by kidding the R-Pi that it has an Official display attached. You may like to look at https://e2e.ti.com/support/interface/digital_interface/f/130/t/670554 where you'll see a little about my 'mission of discovery'! I have not yet crac...
by mbt28
Tue Jul 10, 2018 2:29 pm
Forum: Device Tree
Topic: DSI Device Tree Entries - module probe not being called
Replies: 12
Views: 3715

Re: DSI Device Tree Entries - module probe not being called

Hi,

I have built a board based on the same chip and ordered it from china few days ago.

How is your progress with it? Could you able to make it work?
by mbt28
Mon May 28, 2018 8:00 pm
Forum: General discussion
Topic: Automotive grade power supply
Replies: 3
Views: 493

Re: Automotive grade power supply

This won't be easy. At the input side, you need to accommodate potential accidental reverse polarity (somebody connects a battery the wrong way around), voltage dips and spikes, and "load dump" (the alternator output suddenly losing regulation and reaching 60V or more). You need to ensure the unit ...
by mbt28
Mon May 28, 2018 6:02 pm
Forum: General discussion
Topic: Automotive grade power supply
Replies: 3
Views: 493

Automotive grade power supply

Hi, For my project I need to design automotive grade power supply to my pi. Car is a harsh environment and in my project there are linbus drivers, audio dacs and lcd controllers so I should keep things low noise and low dropout. But I have missing knowledge on few things: Should I first regulate 12V...
by mbt28
Mon May 28, 2018 1:06 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Maximum Power Output From DSI port
Replies: 4
Views: 571

Re: Maximum Power Output From DSI port

NO! The 3V3 comes from exactly the same 5V to 3V3 converter source as the 3V3 going to GPIO's, the amount the converter can deliver depends on the model pf PI you are using, but even in the best case it will not be much more than a few hundred mA, probably much less. Don't feed 3V3 to the GPIO from...
by mbt28
Mon May 28, 2018 10:20 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Maximum Power Output From DSI port
Replies: 4
Views: 571

Maximum Power Output From DSI port

Hi,

What is the maximum current that I get from 3.3V output of display connector? If I feed 3.3V trough GPIO can I get more more current from this connector?

Thanks
by mbt28
Mon May 07, 2018 12:33 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Using ESP32 as wifi+ble device for CM3
Replies: 1
Views: 836

Re: Using ESP32 as wifi+ble device for CM3

Hi,

If you are trying to use Esp32 as slave it is not possible in current case because of lack of necessary firmware.
by mbt28
Mon May 07, 2018 12:29 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: two salvaged displays
Replies: 1
Views: 334

Re: two salvaged displays

You can use spi interface I beleive.
by mbt28
Mon May 07, 2018 12:24 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Capacitive touchscreen + controller board for Raspverry Pi
Replies: 4
Views: 2242

Re: Capacitive touchscreen + controller board for Raspverry Pi

Hi, Capacitive touch screens you can use if they have i2c or spi interface. Most of the linux drivers are already available. Otherwise, for I2c to usb I already wrote an arduino firmware which is a usb hid actually but the code is in big mess and I never had a chance to upload it to github. Since I ...
by mbt28
Sun May 06, 2018 7:57 pm
Forum: Device Tree
Topic: I2S clocks, GPCLK0
Replies: 62
Views: 16927

Re: I2S clocks, GPCLK0

But raspberry still uses 2 frames per channel. So how everytime will it be sure that we have correct sync? For example fpga can start to make fake lrck to dac when raspberry pi were transferring ch 3,4, 5,6,1,2 than the channels will be completely replaced.
by mbt28
Sun May 06, 2018 5:29 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PCM1794 and hardware volume control
Replies: 0
Views: 281

PCM1794 and hardware volume control

Hi, I would like to design stereo mode dac with PCM1794 which output 5 differential channels. 2*stereo + 1 mono. However I would like to have good volume control for each channel via I2C or spi. Crossing over is done by amplifier but the unfortunately there are no volume control option. Are there an...
by mbt28
Sun May 06, 2018 5:24 pm
Forum: Device Tree
Topic: I2S clocks, GPCLK0
Replies: 62
Views: 16927

Re: I2S clocks, GPCLK0

I'm not sure I've understood your question, but LRCK provides the left/right sync, and the change indicates the beginning of each channel. We have to trust that the software layers and DMA engine haven't swapped the channels somewhere down the line. Hi, I just meant we are sending 2 samples in each...
by mbt28
Fri May 04, 2018 2:05 pm
Forum: General discussion
Topic: Backlight Controller Suggestion
Replies: 1
Views: 592

Re: Backlight Controller Suggestion

I just realized I haven't attached the necessary backlight requirements of my LCD.
by mbt28
Fri May 04, 2018 2:03 pm
Forum: Device Tree
Topic: I2S clocks, GPCLK0
Replies: 62
Views: 16927

Re: I2S clocks, GPCLK0

Phil's explanation is correct, here's how the I2S and clock signals wiring will look like: FPGA is the clock master and provides the following clock outputs: - a single BCLK output, this is connected to both RPI and codec BCLK inputs. - a MCLK output to the codec - a LRCLK_RPI output to the RPi - a...
by mbt28
Thu May 03, 2018 9:53 am
Forum: General discussion
Topic: Backlight Controller Suggestion
Replies: 1
Views: 592

Backlight Controller Suggestion

Hi, I have an lcd and its controller. But I need an backlight controller for it. I couldnt understand very well the backlight controllers logic actually. I need your suggestions: 1) My LCD datasheet shows the backlight configuration as attached. Is it possible to use this controller from aliexpress:...
by mbt28
Fri Feb 24, 2017 11:57 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Add an I2S mic using device tree & simple-audio-card
Replies: 36
Views: 24775

Re: Add an I2S mic using device tree & simple-audio-card

Hi,

I would like to use this IC or another one which have similar I2S interface. (Maybe gps, wifi, bt, fm combo). I2S stereo dac+ I2S stereo in(mic) + I2S stereo in(fm), can all be implemented in the same time?

https://www.silabs.com/documents/public ... 77-A20.pdf
by mbt28
Mon Feb 20, 2017 2:03 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Add an I2S mic using device tree & simple-audio-card
Replies: 36
Views: 24775

Re: Add an I2S mic using device tree & simple-audio-card

I actually want to directly connect fm ic to rapsberry pi, I want to hear your opinions that if raspberry pi capable of having 3 i2s in channel?

1ch I2S mic
2ch (L+R) I2S FM Receiver
by mbt28
Mon Feb 20, 2017 11:56 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Add an I2S mic using device tree & simple-audio-card
Replies: 36
Views: 24775

Re: Add an I2S mic using device tree & simple-audio-card

Hi,

I mean, I would like to use a mono or stereo mic. In addition to that I would like to use an FM receiver over I2S. I suppose It should work with same logic as mic. So in this case 2-3 I2S in to the rpi, is it possible?

Thanks
by mbt28
Thu Feb 16, 2017 2:52 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Add an I2S mic using device tree & simple-audio-card
Replies: 36
Views: 24775

Re: Add an I2S mic using device tree & simple-audio-card

Hi,

How is it possible to implement one mono input and one stereo input? I would like to include i2s fm receiver as stereo input.

Another question, can I use every pin configured as I2S in?

Many thanks
by mbt28
Thu Dec 24, 2015 12:22 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Audio in and out by I2S
Replies: 1
Views: 586

Audio in and out by I2S

Hi,

Can I have both audio in and out by I2S with arduino zero? According to BCM2835 datasheet it is possible but I couldnt see any example or guide about how to use I2S ADC with RPI? Does anybody knows any guide or any starting point?

Many thanks.
by mbt28
Fri Feb 06, 2015 3:33 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Raspberry Pi IBUS and Powering
Replies: 1
Views: 2348

Re: Raspberry Pi IBUS and Powering

Since MCP2025 uses parallel method to communicate it is not possible to directly connect these ports. Here I made another scheme to simplify the logic. Feel free to comment on it. Vreg output from MCP2025 triggers the Timer circuit based on 555, there would be a potans to adjust it, I am thinking on...

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