OpenMV

deshipu

Good idea, done.

deshipu

Hello, I just wanted to drop a quick note that I made this very simple PCB adapter for using shields for the D1 Mini boards with the OpenMV boards: shot.png It's really simple, just remapping the pins and adapting to the different size of the shield. I left the TX and RX pins unconnected, because Op...

deshipu

One possible difference is that Arduino UNO is 5V, whicle OpenMV is 3.3V — perhaps your motor driver expects 5V signal?

deshipu

That lone "*" is a syntax error. Remove it.

deshipu

Try

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img.binary(*threshold)

deshipu

You want i//8 not i/8 though. Or just i >> 3.

deshipu

Actually the machine module is the new, cross-port-compatible API, and pyb is the legacy API originally only for the PyBoard (but it has been blindly copied to other ports). If you are writing libraries, you should be using the machine module, because this way they will be compatible with all ports ...

deshipu

Looking at your "schematic" I can also see that you don't have pull-up resistors on the I2C lines. You need those for I2C communication to work -- perhaps you should read more about the I2C protocol.

deshipu

Ah, I see the problem. You are using i2c from pyb, while this library expects i2c from the machine module, which has a different API. Can you give detailed advice? Not sure how I can be more detailed. You need to use this: http://docs.openmv.io/library/machine.I2C.html and not this: http://docs.ope...

deshipu

Ah, I see the problem. You are using i2c from pyb, while this library expects i2c from the machine module, which has a different API.

deshipu

That code looks a lot like my library for the PCA9685 chip available here: https://github.com/adafruit/micropython ... it-pca9685 but some things are changed. I'm using that library with my servo shield, and it works fine, so if it doesn't work for you, perhaps it's because of the changes you made?

deshipu

You have to run the lcd example for this to work.

deshipu

Mind explaining more about this thing? Maybe we can build it. We've got a little more cash in our coffers now and we can afford to build a servo control shield if the price is not that high. Looks like you don't have enough power conditioning on the 5V line though. How do you power it? How do you m...

deshipu

For everyone who want to add more servos to their OpenMV, I designed a servo shield. It uses a popular PCA9685 PWM chip and works with the Adafruit library for MicroPython. For details see the project page at https://hackaday.io/project/21038-servo ... for-openmv

deshipu

You are right, that works perfectly, sorry!

deshipu

Shame you didn't move them to A4 and A5, then you would have the option for I²C

deshipu

I have my servo shield assembled and ready for testing, so I of course wanted to try it with the PCA9685 library from https://github.com/adafruit/micropython-adafruit-pca9685 Unfortunately, I can't figure out how to properly use machine.I2C on the OpenMV board. I tried this (with nothing connected):...

deshipu

If the holes are fixed in relation to the camera, then it should be very easy to do.

deshipu

Is the thing in which the holes are fixed in relation to the OpenMV camera, or can any of them move? Are the lighting conditions constant, or can they change? If they change, can you provide your own light?

deshipu

I suppose you could use the same SPI bus as the wifi shield uses, and use one of the free pins as CS...

deshipu

I would consider using I2C instead of UART. You have the A4 and A5 pins free on the Arduino, so you can make it into an I2C slave. This way you can connect more things to those two pins. Here's an example of a Pro Mini-based servo controller that uses I2C for communication: https://hackaday.io/proje...

deshipu

My board uses I2C on pins P4 and P5 for communication. Looking at the picture at the top, those pins seem to be free, but I didn't test it yet.

deshipu

By the way, I'm working on a PCA9685-based servo shield for the OpenMV, maybe that would be more useful?

: shot.png (225.95 KiB) Viewed 15627 times

deshipu

You probably want to power the servos and ESCs from the VIN pin, and not from the 3.3V pin on the OpenMV anyways, and you can have 5V there. I'm doing a similar thing in my hexapod robot for controlling the servos -- I'm using a 3.3V Pro Mini, which I power through the RAW pin with 5V, together with...

deshipu

I think it would be *much* faster to first find the line on the image, and *then* apply the perspective transformation to the ends of that line, instead of applying it to each and every pixel in the image.

deshipu

Thank you for your thoughts, this is an excellent summary.

Personally I'm sticking to OpenMV, as it fits my use cases much better. Thanks for making it possible.

deshipu

I just stumbled upon this kickstarter, it looks like it aims to fill a similar niche as the OpenMV: https://www.kickstarter.com/projects/1602548140/jevois-open-source-quad-core-smart-machine-vision Of course, they are doing it a bit differently -- instead of developing optimized code for a battery-f...

deshipu

That sounds reasonable. Perhaps it would be good to have a way to bypass the filtering altogether, in case of a really weird system setup -- for instance, a button that makes it display all mounted drives, or even lets you just enter a path.

deshipu

I wonder how hard it would be to have a remote REPL, similar to telnet?

deshipu

I just tried again, and it worked this time. I wonder what happened.

deshipu

Hi, I finally found some time to try the WiFi shield. I'm using the new IDE, and I upgraded the firmware with what shipped with it. I have the shield connected, and I tried the "mjpeg_streamer" example, changing the SSID and KEY variables to match my local network. The terminal displayed this: Micro...

deshipu

The EFI partition has "EFI System" as the parition type:

/dev/sdb1 2048 999423 997376 487M EFI System

But I think that it actually has a FAT filesystem on it.

deshipu

I think this is one of the first cameras with the new sensor. You sent it to me for testing, after I tested the fire-sale camera a bit. Perhaps it's somehow different from the kickstarter ones (I haven't yet unpacked those).

deshipu

After clicking "connect" I get a message box with "name=ttyACM0,hasVID=1,hasPID=1,VID=8086,POD=1e26" with this version. Then it prompted me to upgrade the firmware, the to erase the filesystem, then it began programming. Once finished, it asked me to wait for reconnect before continuing. Then it dis...

deshipu

Thanks, I will try it. By the way, you could add a mime type to your web server configuration (or a content-disposition header), so that it doesn't serve those files as text, but downloads them instead. Just a small thing.

deshipu

Yes, it appears as a disk and as a serial on /dev/ttyACM0. I can use screen to have normal python console there.

deshipu

I removed the udev rules, but still no joy. The log in dmesg when I connect my cam is: [875424.766530] usb 2-1.2.2: new full-speed USB device number 36 using ehci-pci [875424.877244] usb 2-1.2.2: New USB device found, idVendor=1209, idProduct=abd1 [875424.877254] usb 2-1.2.2: New USB device strings:...

deshipu

Oh, I have the udev rules installed for it, should I remove them?

deshipu

I just tried the new IDE, downloaded from http://openmv.io/upload/openmv-ide-linux-x86_64-1.1.0/openmv-ide-linux-x86_64-1.1.0.run -- is that the most recent working one? I couldn't get it to work on my Ubuntu. Trying to connect tells me "no openmv cams found" and then asks me if I'd like to unbrick ...

deshipu

I use the ADC precisely for that, and I just use a simple voltage divider made of two equal resistors (47kΩ, I think), which halves the voltage. This way I have a bit of a margin there (I don't need my measurements to be very precise).

deshipu

Thanks, that makes sense.

deshipu

From the random nature of the problem, I would infer that it may be something wrong with the USB connection. I would try to use a different USB port, different USB cable, etc. Hope that helps.

deshipu

I would first make sure that the USB cable you are using has data lines. There are some cheap "charging only" cables out there, that don't allow communication with your computer.

deshipu

Are you using pyinstaller to generate the executable? If so, you may be hitting this: https://github.com/pyinstaller/pyinstaller/issues/847

deshipu

Hmm, I have "arm-none-eabi-gcc (15:4.9.3+svn227297-1) 4.9.3 20150529 (prerelease)" -- must be one of the things I installed for the Micro:Bit port of micropython.

deshipu

That works. I guess it's the environment then. I'm using whatever comes by default in Ubuntu...

deshipu

I first tried "make flash_dfu", then "make flash_bin", and then "make flash_boot" followed by "make flash_image" -- all with the same result.

deshipu

Tested on the one with the old sensor (from the fire sale), and I get the same error.

deshipu

Thank you, that let it compile.

However, when I flashed it, I got the dreaded:

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FATAL ERROR:
Failed to init sensor, error:-2

in the

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ERROR.log

file, and of course I can't connect to the camera with the IDE...

This is the one with the new sensor.

deshipu

After a long pause (got busy with other things, sorry), I tried to build the firmware to see all the progress that happened in the mean time. Unfortunately, I'm getting this error: /usr/lib/gcc/arm-none-eabi/4.9.3/../../../arm-none-eabi/bin/ld: /home/sheep/dev/3rdparty/openmv/src/../firmware/OPENMV2...

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