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by Hove
Thu Jun 15, 2017 5:46 pm
Forum: Camera board
Topic: SOLVED:Pi Camera V2 video compression in GPU, CPU or camera?
Replies: 11
Views: 3468

Re: SOLVED:Pi Camera V2 video compression in GPU, CPU or cam

More RAM was very speculatively aimed to lower memory paging to file, and hence possible higher performance. The code already has 5 processes! - main motion processing using I2C sensors to drive the props based upon... - GPS processor - Autopilot (which will do all the work for mapping the maze, and...
by Hove
Thu Jun 15, 2017 4:56 pm
Forum: Camera board
Topic: SOLVED:Pi Camera V2 video compression in GPU, CPU or camera?
Replies: 11
Views: 3468

Re: SOLVED:Pi Camera V2 video compression in GPU, CPU or cam

Correct, it is done in one of the GPU hardware blocks. I'm not quite seeing why that has any impact on the memory split, but there you go. On receipt of the macro-blocks from python picamera, my code does a lot of processing on it to find a cluster of macro-blocks that agree with each other as to t...
by Hove
Thu Jun 15, 2017 9:41 am
Forum: Camera board
Topic: SOLVED:Pi Camera V2 video compression in GPU, CPU or camera?
Replies: 11
Views: 3468

Re: SOLVED:Pi Camera V2 video compression in GPU, CPU or cam

courtesy of waveform who wrote python picamera, the answer is GPU (kinda what I expected, but had hoped not). The reason behind this is there's another sensor, an IMU whose fixed length FIFO must never be allowed to overflow or all hell breaks loose. At the same time though, the Picamera compression...
by Hove
Thu Jun 15, 2017 8:59 am
Forum: Camera board
Topic: SOLVED:Pi Camera V2 video compression in GPU, CPU or camera?
Replies: 11
Views: 3468

SOLVED:Pi Camera V2 video compression in GPU, CPU or camera?

I'm trying to select the right memory split between CPU & GPU. I am using the RPi Camera for video, discarding the video itself, but using the compression macro-blocks to produce motion vectors. Anyone know where the video compression happens? CPU, GPU or camera? This will have a critical effect on ...
by Hove
Thu Jun 01, 2017 8:27 pm
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

KrookdFinger wrote:Latest Kernel Patch for i2c discussed here

https://patchwork.kernel.org/patch/9351755/
I'll stick with my March RPi kernel then until I've got time to read the details of what's posted - thanks for sharing.
by Hove
Tue May 30, 2017 6:15 pm
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

Haven't tried the latest jessie, but for all between January and March, using the full length cables (with or without the electrolytic) always cause corruption / noise on I2C. Shortening them as short as you can always fixes the problem.
by Hove
Sun May 28, 2017 7:38 am
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

I just removed the capacitor completely and shorten the wires. To me it seems about 10cm cables is about the point things start failing even with the capacitor removed.
by Hove
Sun May 28, 2017 7:14 am
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

How is your LiDAR attached to the Raspberry Pi? I haven't seen problems matching exactly what you see, but I have seen getting rubbish values from it. The main problem I've had is the wires they give are too long - if they are 1/2 or less in length, it works a lot better. Also, the LiDAR spec says t...
by Hove
Sun May 28, 2017 6:06 am
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

Stupid question, in your (Hove's) code, I see self.i2c = I2C(address) But I don't see I2C defined anywhere. What would I need to import to get that? Thanks I2C is just a thin wrapper around smbus which is imported at the top. Take a look at github.com/PiStuffing/Quadcopter/Quadcopter.py, and look f...
by Hove
Tue May 23, 2017 10:19 am
Forum: Advanced users
Topic: Overclock RPi 2B+ v1.2 to 1.2GHz?
Replies: 5
Views: 3744

Re: Overclock RPi 2B+ v1.2 to 1.2GHz?

Thx - my 2B+ is now running at 1.2GHz happily.
by Hove
Tue May 23, 2017 9:27 am
Forum: Advanced users
Topic: Overclock RPi 2B+ v1.2 to 1.2GHz?
Replies: 5
Views: 3744

Re: Overclock RPi 2B+ v1.2 to 1.2GHz?

Thanks - it's actually overclocking a B2+ to 1.2GHz I'm after - i.e. the upgraded B2 as of last autumn. What I'm being cautious about are the settings for the other parameters in addition to arm_frequency as I don't know the correlation between these? arm_freq=1000 core_freq=500 sdram_freq=600 over_...
by Hove
Tue May 23, 2017 9:03 am
Forum: Advanced users
Topic: Overclock RPi 2B+ v1.2 to 1.2GHz?
Replies: 5
Views: 3744

Overclock RPi 2B+ v1.2 to 1.2GHz?

There must be something on google for this, but somehow I'm failing to find it so... Using a 3B, its brown out LED flashes constantly with Jessie Lite on 2.4 LiPo power bank probably due to (I'm guessing) herd of sensors - GPS, external WiFi, IMU + RaspiCam - internal WiFi & BT blacklisted already. ...
by Hove
Sat May 20, 2017 5:28 am
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

Do you have anything else on the I2C bus other than Garmin? My Garmin works perfectly, but iff its plugged in, my MPU-9250 struggles.

Have you set the I2C baudrate to 400kbps? Have you tried the Python code I posted earlier - this works for me.
by Hove
Tue May 16, 2017 6:16 am
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

Hi Robert, Sorry, can't help; I think mine are running on the March Jessie lite, but I know they've run on the January & February versions too.I'd be very surprised that I2C got broken in the April version. Do you have any other I2C devices that are still working fine? I have found the LiDAR Lite is...
by Hove
Mon May 15, 2017 3:28 pm
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

Any official version of Jessie should work fine - just get the latest version: https://www.raspberrypi.org/downloads/raspbian/ I use the lite version - I don't want PIXEL and all the other GUI stuff taking up CPU power, but that will have no effect on the I2C. The only changes I make to I2C are enab...
by Hove
Sun May 14, 2017 5:05 am
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

Hey Guys, I had the Lidar Lite V3 working just fine... just upgraded firmware and now I am not getting any distance information back. i2cdetect shows connected at 0x62. No errors in my software... distances just not coming in now. Firmware version 4.9.27-v7+ Any ideas what to do? Thanks. I've never...
by Hove
Fri May 12, 2017 6:35 pm
Forum: Automation, sensing and robotics
Topic: [RESOLVED]Telling 2 ttyUSB*'s apart
Replies: 11
Views: 1813

Re: Telling 2 ttyUSB*'s apart

I've managed to set up the symlink to my GPS UART so I can now just reference /dev/ttyGPS regardless of which /dev/ttyUSB* is there; the Scanse Sweep UART isn't working yet, but given the GPS is, it's probably an error in my /etc/udev/rules.d/99-usb-serial.rules. I'll post again once I track this d...
by Hove
Fri May 12, 2017 3:33 pm
Forum: Automation, sensing and robotics
Topic: [RESOLVED]Telling 2 ttyUSB*'s apart
Replies: 11
Views: 1813

Re: Telling 2 ttyUSB*'s apart

I've managed to set up the symlink to my GPS UART so I can now just reference /dev/ttyGPS regardless of which /dev/ttyUSB* is there; the Scanse Sweep UART isn't working yet, but given the GPS is, it's probably an error in my /etc/udev/rules.d/99-usb-serial.rules. I'll post again once I track this do...
by Hove
Thu May 11, 2017 5:56 am
Forum: Automation, sensing and robotics
Topic: [RESOLVED]Telling 2 ttyUSB*'s apart
Replies: 11
Views: 1813

Re: Telling 2 ttyUSB*'s apart

That's perfect, thanks - that means I can sort this out as a boot-time scripts, and create custom names that the code will rely on such as ttyGPS and ttySweep. Thanks
by Hove
Wed May 10, 2017 6:49 pm
Forum: Automation, sensing and robotics
Topic: [RESOLVED]Telling 2 ttyUSB*'s apart
Replies: 11
Views: 1813

Re: Telling 2 ttyUSB*'s apart

Martin, thanks, that's another option for me to dig into. It seems the simplest to interpret so far.
by Hove
Wed May 10, 2017 5:25 pm
Forum: Automation, sensing and robotics
Topic: [RESOLVED]Telling 2 ttyUSB*'s apart
Replies: 11
Views: 1813

Re: Telling 2 ttyUSB*'s apart

Thanks I'll have a dig.
by Hove
Wed May 10, 2017 3:31 pm
Forum: Automation, sensing and robotics
Topic: [RESOLVED]Telling 2 ttyUSB*'s apart
Replies: 11
Views: 1813

Re: Telling 2 ttyUSB*'s apart

Thanks Mark,

Thanks for the suggestion, I'll have an investigate to see if any can produce the software fix rather than having to use ttyUSB0 and ttyAMA0 instead (which requires a hardware PCB fix).
by Hove
Wed May 10, 2017 8:43 am
Forum: Automation, sensing and robotics
Topic: [RESOLVED]Telling 2 ttyUSB*'s apart
Replies: 11
Views: 1813

[RESOLVED]Telling 2 ttyUSB*'s apart

I'll soon have both GPS and another sensor both plugged into RPi 3 USB ports. Each on their own show up as ttyUSB0. Their serial connections are quite different; for example, the GPS runs at 9600 baudrate whereas the other runs at 115200 baudrate. Is there a way to know / force a specific sensor to ...
by Hove
Thu Apr 20, 2017 5:18 am
Forum: Beginners
Topic: Lidar Lite V3 - Raspberry Pi - Python
Replies: 32
Views: 16884

Re: Lidar Lite V3 - Raspberry Pi - Python

I do use the smbus in my code, but because I have 3 sensors using it, it's broken out in a different class shared by all three. Have a look on GitHub at Quadcopter.py https://github.com/PiStuffing/Quadcopter/blob/master/Quadcopter.py . The code up to line 145 is the smbus class which the LiDAR code ...

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