Go to advanced search

by mkirk
Wed May 19, 2021 8:18 pm
Forum: Camera board
Topic: Raspberry pi camera pinout
Replies: 4
Views: 594

Re: Raspberry pi camera pinout

If the GPIO lines to camera are floating, won't they pick up noise?

Might be better to enable GPIO on Pi as output and drive to ground potential?
by mkirk
Sat Mar 27, 2021 5:16 am
Forum: General discussion
Topic: Raspberry Pi 4B AP+STA mode on single inbuilt wifi adapter
Replies: 3
Views: 449

Re: Raspberry Pi 4B AP+STA mode on single inbuilt wifi adapter

We have working on Buster - but as mentioned on other threads, don't expect to get more than 4 or 5 clients to connect to the AP reliably. Adding more will cause it to slow down - and lose connections. The CYW43455 WiFi on-chip RAM is the limiting factor - it can't handle > 5 clients - as I understa...
by mkirk
Sat Mar 27, 2021 5:09 am
Forum: Networking and servers
Topic: Pi 4 as a Wifi AP and a Wifi Client at the same time?
Replies: 4
Views: 1444

Re: Pi 4 as a Wifi AP and a Wifi Client at the same time?

We have Pi 4B as both AP and client (STA) as described. We use Raspbian Buster OS. Both AP and STA must use same WiFi channel (frequency). Only issue we have found is due to CYW43455 WiFi chip - only 5 clients can attach reliably to AP. Seems there is not sufficient RAM on WiFi chip to support more ...
by mkirk
Sat Feb 27, 2021 3:37 pm
Forum: Python
Topic: Pi camera H.264 stream with ffmpeg not working within Python
Replies: 2
Views: 660

Re: Pi camera H.264 stream with ffmpeg not working within Python

I have also tried raspivid piped to ffmpeg.
Works OK on command line, but fails in Python3. Error: "decoding for stream 0 failed"

Code: Select all

raspivid -t 30000 -o - | ffmpeg -y -i pipe: -vcodec copy -f mp4 -t 30 out.mp4
by mkirk
Sat Feb 27, 2021 5:52 am
Forum: Python
Topic: Pi camera H.264 stream with ffmpeg not working within Python
Replies: 2
Views: 660

Pi camera H.264 stream with ffmpeg not working within Python

I need to save Pi camera to file on Pi 4B running Buster within Python (v 3.7.3) script. No transcoding/filtering just straight copy to keep CPU load low. ffmpeg works on command line correctly: ffmpeg -y -input_format h264 -f v4l2 -i /dev/video0 -vcodec copy -f mp4 -t 30 out.mp4 Result is good - co...
by mkirk
Thu Feb 04, 2021 4:44 pm
Forum: Advanced users
Topic: Pi 4B - USB has diode to prevent backfeed?
Replies: 5
Views: 769

Re: Pi 4B - USB has diode to prevent backfeed?

Thanks for this info. Could I cut the USB +5V from the hard drive and supply +5Vdc power to drive with a separate supply? Ground would be common. That should prevent current overload on Pi USB. Would also save the cost and space of a USB hub. I have read some powered USB hubs don't have a diode to p...
by mkirk
Thu Feb 04, 2021 4:52 am
Forum: Advanced users
Topic: Pi 4B - USB has diode to prevent backfeed?
Replies: 5
Views: 769

Pi 4B - USB has diode to prevent backfeed?

On the Pi 4B I used my meter to check 5 volt power on the USB 2.0 and 3.0 ports. There is not a direct connection to 5V pins 2 and 4 on header, but there appears to be a diode in the path (top of board, close to USB3.0 connector) marked 100 96TRD. Can someone confirm that this diode is to prevent US...
by mkirk
Tue Oct 20, 2020 10:14 pm
Forum: Advanced users
Topic: Influence of Core Frequency
Replies: 12
Views: 1132

Re: Influence of Core Frequency

We need PLO11 for the BT function. And our hardware PCB is complete. We may use Pi 3B+ or 4B in our products, so we are stuck for now with miniUART and core clock at 250 MHz. Going forward, if we redesign hardware and only use Pi 4B, we can switch and use one of the 4 PL011 UARTs as you suggest.
by mkirk
Tue Oct 20, 2020 8:23 pm
Forum: Advanced users
Topic: Influence of Core Frequency
Replies: 12
Views: 1132

Re: Influence of Core Frequency

Just setting enable_uart=1 in /boot/config.txt did not work for me. I need to run mini UART at 600 baud (using slow optocoupler for high-voltage AC isolation). At 500 MHz core clock, lowest baud supported is 954 baud >> 500MHz/(8*(65535+1)) vcgencmd measure_clock core command gives 500 MHz with only...
by mkirk
Tue Oct 20, 2020 7:59 pm
Forum: Advanced users
Topic: Influence of Core Frequency
Replies: 12
Views: 1132

Re: Influence of Core Frequency

What is the performance impact (slow down) of setting core_freq=250 in /boot/config.txt on Pi 4B? This is needed to run the Mini UART, I see the ISP and V3D still show 500 MHz clock (vcgencmd measure_clock isp / v3d ) but core is at 250 MHz. Without core_freq=250, core shows 500 MHz clock. Does it s...
by mkirk
Fri Aug 14, 2020 4:39 pm
Forum: Camera board
Topic: Pi camera - control parameter interactions/hierarchy
Replies: 0
Views: 1401

Pi camera - control parameter interactions/hierarchy

I am looking for a good reference (thread post, website, PDF) on camera control parameters. I have a read the "Official Raspberry Pi Camera Guide" but was looking for more details on parameter interaction. Specifically interested in how these parameters interact: sensor_mode, shutter_speed...
by mkirk
Tue Jul 21, 2020 6:30 pm
Forum: General discussion
Topic: FCC Part 15 Subpart B compliance
Replies: 3
Views: 395

Re: FCC Part 15 Subpart B compliance

Yes, thanks.

I see all have EU conformity, but Pi 3B, 3B+ and 4B have no FCC Part 15 B statement - only Part 15 C and E .

Does EU EMC conformity based on ITE EN 55032 and EN55024 imply compliance with FCC Part 15 B?

-Mike
by mkirk
Tue Jul 21, 2020 4:26 pm
Forum: General discussion
Topic: FCC Part 15 Subpart B compliance
Replies: 3
Views: 395

FCC Part 15 Subpart B compliance

Raspberry Pi products with WiFi and Bluetooth transmitters (3B, 3B+, 4B) have been tested for FCC (US), IC (Canada) and other national compliance requirements for intentional radiators. For the USA, this is FCC Part 15 Subpart C (intentional radiator). Has the Pi family also been certified for FCC P...
by mkirk
Tue May 05, 2020 9:05 pm
Forum: Camera board
Topic: STICKY: libcamera - open source camera stack
Replies: 134
Views: 39951

Re: STICKY: libcamera - open source camera stack

So just tell the camera/ISP to give you smaller frames. Makes no difference to the performance. Thanks Jamesh - I could do what you suggest. When I said 'viable' above, I meant in terms of product cost. Using a more expensive 8 or 12MP camera and then reducing the ISP output to 2MP won't meet our c...
by mkirk
Tue May 05, 2020 4:39 pm
Forum: Camera board
Topic: STICKY: libcamera - open source camera stack
Replies: 134
Views: 39951

Re: STICKY: libcamera - open source camera stack

How does the Atmel ATSHA204A security chip factor into use of libcamera ? Does the Pi (at boot time) still authenticate the camera (iMX219 8MP and iMX477 12 MP) before allowing use? Or could someone make their own iMX219 camera module (without authentication chip) and have it work? I understand tha...
by mkirk
Tue May 05, 2020 4:31 pm
Forum: Camera board
Topic: STICKY: libcamera - open source camera stack
Replies: 134
Views: 39951

Re: STICKY: libcamera - open source camera stack

The IMX477 and IMX219 sensors will always require the security chip to be in place to function correctly, unless you are using the compute module product which does not require the security chip. The whole concept of the libcamera library and unicam driver is to enable you to develop and tune your ...
by mkirk
Mon May 04, 2020 11:20 pm
Forum: Camera board
Topic: STICKY: libcamera - open source camera stack
Replies: 134
Views: 39951

Re: STICKY: libcamera - open source camera stack

How does the Atmel ATSHA204A security chip factor into use of libcamera ? Does the Pi (at boot time) still authenticate the camera (iMX219 8MP and iMX477 12 MP) before allowing use? Or could someone make their own iMX219 camera module (without authentication chip) and have it work? I understand that...
by mkirk
Thu Feb 06, 2020 2:45 pm
Forum: Compute Module
Topic: Compute Module 4
Replies: 90
Views: 19699

Re: Compute Module 4

How about a CM3+ module with 2GB or 4GB DDR?

Would that be a simple BOM change? Or are more address lines needed?
by mkirk
Tue Feb 04, 2020 8:21 pm
Forum: Compute Module
Topic: CM3 Flashing on Windows 7 broken?
Replies: 13
Views: 9103

Re: CM3 Flashing on Windows 7 broken?

This last update worked for me on Win7 64 bit Thanks! On my system, the directory is: C:\Program Files (x86) \Raspberry Pi\redist So the command is (from C:\ prompt) C:\>cd "Program Files (x86)\Raspberry Pi\redist" C:\Program Files (x86)\Raspberry Pi\redist> wdi-simple.exe -n "Raspber...
by mkirk
Tue Nov 05, 2019 9:33 pm
Forum: General discussion
Topic: RPi 4 B Not Switching to 600 MHz GPU
Replies: 22
Views: 4449

Re: RPi 4 B Not Switching to 600 MHz GPU

I am seeing similar issues with Buster on Pi 4 and 3B+. vcgencmd measure_clock arm gives 600 MHz clock even when running stress -c 4 on all 4 cores. Trying the Pi 3B+ with Stretch gives expected result - 1400 MHz clock is reported.
by mkirk
Wed Sep 25, 2019 8:48 pm
Forum: Compute Module
Topic: [SOLVED] CM3 Plus and WiFi/BT CYW43455
Replies: 115
Views: 27585

Re: CM3 Plus and WiFi/BT CYW43455

These modules also require port pins to control one or more of these signals: WL_HOST_WAKE WL_REG_ON BT_REG_ON BT_HOST_WAKE BT_DEV_WAKE Are these pins controlled by the driver? A DT overlay is needed to map them to GPIO so the driver can use them? Or should the application set these pins as needed ?...
by mkirk
Thu Sep 19, 2019 2:27 pm
Forum: Compute Module
Topic: [SOLVED] CM3 Plus and WiFi/BT CYW43455
Replies: 115
Views: 27585

Re: CM3 Plus and WiFi/BT CYW43455

OK -thanks. This will target the SD1 (ALT3) for WiFi and not affect the SD0 (ALT0) used by the micro SD flash filesystem?

And I would do a similar dt-overlay=uart0 for the PL011 serial port to interface the HAT Bluetooth instead of the on-board chip?
by mkirk
Thu Sep 19, 2019 2:11 pm
Forum: Compute Module
Topic: [SOLVED] CM3 Plus and WiFi/BT CYW43455
Replies: 115
Views: 27585

Re: CM3 Plus and WiFi/BT CYW43455

Murata makes the 1MW Wifi/BT module https://wireless.murata.com/type-1mw.html This uses same CYW43455 chipset as on Pi 3B+ and Pi 4. The 1MW is FCC/IC certified and will support external antennas. We need an external antenna which Pi 3B+ does not offer. Can we disable on-board CYW43455 and connect t...
by mkirk
Mon Sep 16, 2019 4:24 pm
Forum: Compute Module
Topic: [SOLVED] CM3 Plus and WiFi/BT CYW43455
Replies: 115
Views: 27585

Re: CM3 Plus and WiFi/BT CYW43455

Another question, Is the WiFi/BT module on the Pi4 and 3B+ available for purchase and use on a CM3+ carrier board? Meaning it is a metal can encapsulating a complete WiFi/BT module on a PCB - that is soldered to the Pi PCB? Or are there discrete components (including the CYW43455) soldered to the Pi...
by mkirk
Mon Sep 09, 2019 6:31 pm
Forum: Compute Module
Topic: [SOLVED] CM3 Plus and WiFi/BT CYW43455
Replies: 115
Views: 27585

Re: CM3 Plus and WiFi/BT CYW43455

PhilE: Thanks for this info, I was not aware of this HAT board. And yes, Roger Thornton has my inputs posted above. The Red Bear IoT WiFi/BT HAT appears to be discontinued - Red Bear is now part of Particle. However, the reference info and schematics showing the required connections are very helpful...

Go to advanced search