Search found 33 matches

by dhylands
Thu May 24, 2018 1:47 pm
Forum: General Topics
Topic: Robotic Arm 6DOF arduino uno with OpenMV
Replies: 3
Views: 1606

Re: Robotic Arm 6DOF arduino uno with OpenMV

Not sure why you would say that Arduino can't be an I2C slave. I've written AVR I2C slaves in the past (admittedly not using Arduino) and they worked quite well. I can point anybody that's interested to my code (which also includes an i2c bootloader). However, even with that, I'd still probably use ...
by dhylands
Tue May 30, 2017 12:56 pm
Forum: Technical Discussion
Topic: Can't see OpenMV on Ubuntu despite doing adduser dialout
Replies: 4
Views: 2919

Re: Can't see OpenMV on Ubuntu despite doing adduser dialout

Different distros setup the group stuff differently, so the real answer is to look at the /dev/ttyACM0 file and see which group it belongs to and whether there are even group write permissions.
by dhylands
Thu Feb 23, 2017 6:44 pm
Forum: Technical Discussion
Topic: Hw reset and/or reboot?
Replies: 12
Views: 7708

Re: Hw reset and/or reboot?

I like to use rshell to copy files onto and off of my MicroPython boards, and it relies on pyboard.py which also relies on Control-D doing a soft-reset actually working.
by dhylands
Sun Jan 29, 2017 6:22 pm
Forum: Technical Discussion
Topic: Use of Servo class - 3-wire hobby servo driver
Replies: 2
Views: 1843

Re: Use of Servo class - 3-wire hobby servo driver

servo.speed is intended to be used with RC servos that have been modified for continuous rotation.
by dhylands
Sun Jan 29, 2017 6:20 pm
Forum: Technical Discussion
Topic: Use of Sharp Optical ranging sensors & OpenMV interaction
Replies: 5
Views: 2906

Re: Use of Sharp Optical ranging sensors & OpenMV interaction

My experience with the sharp sensors (mind you it was the GP2D12) is that you don't need a voltage divider because even though its a 5v device, the output voltage never goes about 3.3v. According to the datasheet, the max voltage out of a GP2D12 is 2.8v, and the newer sensors like the GP2Y0A21YK0F h...
by dhylands
Mon Jan 23, 2017 5:00 pm
Forum: Technical Discussion
Topic: ubinascii
Replies: 11
Views: 5813

Re: ubinascii

Sorry for the delayed response (I decided to test what I suggested). See my post just before yours :)
by dhylands
Mon Jan 23, 2017 3:59 pm
Forum: Technical Discussion
Topic: ubinascii
Replies: 11
Views: 5813

Re: ubinascii

Anytime I get qstr errors, I normally do a clean and rebuild and then they go away. There's a problem with the Makefile dependencies that makes it not rescan for qstrs when it should. ok - It looks like there's a custom Makefile being used as well. So you'll need to edit openmv/src/Makefile. Around ...
by dhylands
Mon Jan 23, 2017 1:55 pm
Forum: Technical Discussion
Topic: ubinascii
Replies: 11
Views: 5813

Re: ubinascii

In the openmv repository, you need to populate the micropython repository by doing git submodule update --init and then you should see files in openmv/src/micropython When you boot the OpenMV board, the banner shows as: MicroPython v1.8-4348-g62d6127 on 2016-12-14; OPENMV2 with STM32F427 which tells...
by dhylands
Fri Jan 20, 2017 9:27 pm
Forum: Technical Discussion
Topic: Hw reset and/or reboot?
Replies: 12
Views: 7708

Re: Hw reset and/or reboot?

I noticed that Control-D *looks* like it does a soft-reset, but doesn't. The heap doesn't get reinitialized and everything seems to still be in memory. If you create a simple module (say bar.py) with just a single line: print('bar.py') and you try and import it twice, then you'll notice that the sec...
by dhylands
Fri Jan 20, 2017 12:55 am
Forum: Technical Discussion
Topic: Hw reset and/or reboot?
Replies: 12
Views: 7708

Re: Hw reset and/or reboot?

You can also do either of the following:

Code: Select all

import machine
machine.reset()
or

Code: Select all

import pyb
pyb.hard_reset()
by dhylands
Thu Jan 19, 2017 3:21 am
Forum: Technical Discussion
Topic: VBUS doesn't seem to be available
Replies: 4
Views: 2531

Re: VBUS doesn't seem to be available

Well, at least with a single diode you have the option of adding an external diode. Anyways, I just soldered a wire to bypass the second diode so that I can power 5v peripherals while using USB power. This is mostly just a convenience of not having to create a USB breakout board in order to test stu...
by dhylands
Wed Jan 18, 2017 4:11 pm
Forum: Technical Discussion
Topic: External access from public ip
Replies: 2
Views: 1602

Re: External access from public ip

If your camera is sitting on a NAT'ed network (most home/office networks fall into this category) then you won't be able to access the camera from the internet unless you setup some port forwarding rules in your router. You'd need to do something like write a script on the camera which uploads to Dr...
by dhylands
Wed Jan 18, 2017 3:52 pm
Forum: Technical Discussion
Topic: I2C from machine vs I2C from pyb
Replies: 33
Views: 12053

Re: I2C from machine vs I2C from pyb

The docs for pyboard's machine.I2C is here: http://docs.micropython.org/en/latest/pyboard/library/machine.I2C.html (so I'm not sure which docs you were looking at). I seem to recall that there may have been some bugs related to clock stretching that were fixed recently. Its possible that OpenMV stil...
by dhylands
Wed Jan 18, 2017 1:35 am
Forum: Technical Discussion
Topic: I2C from machine vs I2C from pyb
Replies: 33
Views: 12053

Re: I2C from machine vs I2C from pyb

It looks like the machine.I2C module included in the current OpenMV (my camera shows v1.8-4348-g62d6127) is SW only machine.I2C which follows the esp8266 documentation: http://docs.micropython.org/en/latest/pyboard/library/machine.I2C.html which requires you to provide sda and scl pins. Newer MicroP...
by dhylands
Wed Jan 18, 2017 1:28 am
Forum: Technical Discussion
Topic: VBUS doesn't seem to be available
Replies: 4
Views: 2531

Re: VBUS doesn't seem to be available

I understand the diode going from VBUS to VIN. It was the second diode going from RAW to VIN that I was referring to.
by dhylands
Tue Jan 17, 2017 10:34 pm
Forum: Technical Discussion
Topic: VBUS doesn't seem to be available
Replies: 4
Views: 2531

VBUS doesn't seem to be available

I was expecting to be able to get access to VBUS on the VCC pin (the one next to P7). Looking ta the schematic, I see a double diode used (D1) which is what is preventing this. On the pyboad, a single diode is used between VBUS and VIN which allows VIN/VCC to be used either as an input or an output....
by dhylands
Tue Jan 17, 2017 7:32 pm
Forum: Technical Discussion
Topic: I2C from machine vs I2C from pyb
Replies: 33
Views: 12053

Re: I2C from machine vs I2C from pyb

The general direction that MicroPython is moving is to eventually phase out the pyb module and replace it with machine module.

The machine module on the pyboard allows both HW and bit banged I2C to be used.

So right now, its really just a question of which API you want to use.
by dhylands
Mon Jan 09, 2017 10:07 pm
Forum: Technical Discussion
Topic: Half-Duplex Operations
Replies: 6
Views: 3051

Re: Half-Duplex Operations

Cool. Just FYI: I have another repository which implements a CLI tool (in Python2) for talking to bioloid devices, https://github.com/dhylands/Bioloid (this was written long before MicroPython existed) The repository with the half-duplex serial stuff: https://github.com/dhylands/bioloid3 will eventu...
by dhylands
Mon Jan 09, 2017 3:39 pm
Forum: Technical Discussion
Topic: SD Card Troubles
Replies: 6
Views: 4253

Re: SD Card Troubles

Personally, I have a strong dislike for the way the current USB Mass Storage is implemented in the pyboard. It can and will corrupt files (because the PC doesn't really have exclusive access). Implementing MTP would provide a filesystem that allows the PC and upy to access simultaneously, but it isn...
by dhylands
Sat Jan 07, 2017 7:55 pm
Forum: Technical Discussion
Topic: SD Card Troubles
Replies: 6
Views: 4253

Re: SD Card Troubles

It looks like the openmv only has either the internal flash (as 0:/) or the sdcard (as 1:/) exposed. So it really is either or. MicroPython on the pyboard exposes them as /flash and /sd. The os.mount() command can be used for mounting an sdcard via the SPI bus, or using a serial flash to store a fil...
by dhylands
Sat Jan 07, 2017 12:27 pm
Forum: Technical Discussion
Topic: SD Card Troubles
Replies: 6
Views: 4253

Re: SD Card Troubles

With the pyboard, you can only access the sdcard or the internal flash via USB Mass Storage (not both at the same time).
You can access both at the same time from within MicroPython itself.
by dhylands
Sat Jan 07, 2017 1:18 am
Forum: Technical Discussion
Topic: Half-Duplex Operations
Replies: 6
Views: 3051

Re: Half-Duplex Operations

You can. See this code for the pyboard (STM32F405): https://github.com/dhylands/bioloid3/blob/master/stm_uart_port.py If you set the HDSEL bit in the uart's CR3 register, then it puts the uart in half-duplex mode, and connects Tx to Rx internally. You only need to use the TX pin externally. I use th...
by dhylands
Sat Dec 17, 2016 1:12 am
Forum: Technical Discussion
Topic: QR Code Decoding
Replies: 17
Views: 7672

Re: QR Code Decoding

There is a nice library in C here: https://github.com/dlbeer/quirc
by dhylands
Mon Oct 03, 2016 1:29 pm
Forum: General Topics
Topic: Kickstarter cams arent working with latest IDE [Ubuntu 16.04]
Replies: 2
Views: 2460

Re: Kickstarter cams arent working with latest IDE [Ubuntu 16.04]

There is a way to setup udev rules to tell modem manager not to look at your device:
https://github.com/micropython/micropyt ... ux-via-dfu
In particular, ID_MM_DEVICE_IGNORE
by dhylands
Sun Oct 02, 2016 9:43 pm
Forum: General Topics
Topic: IDE editor - possible to change to emacs/vim/...xyz?
Replies: 3
Views: 2928

Re: IDE editor - possible to change to emacs/vim/...xyz?

One thing I really like about the editor I use (Visual SlickEdit) is that it has an option to auto-save when the app loses focus and auto-reload when it gains focus back. That way when I switch to any other app, make changes and when I switch back, I've got the updates. This is especially useful whe...
by dhylands
Sat Jul 16, 2016 11:40 pm
Forum: Technical Discussion
Topic: What script runs when you power on the board?
Replies: 5
Views: 3449

Re: What script runs when you power on the board?

Not sure if this is a problem or not, but I get the following errors printed everytime I launch the IDE (linux 64-bit running under ubuntu 16.04): QSqlDatabase: QSQLITE driver not loaded QSqlDatabase: available drivers: Warning: Failed to open settings database at "/home/dhylands/.config/OpenMV/Open...
by dhylands
Wed Jun 22, 2016 1:27 pm
Forum: General Topics
Topic: Segfault in linux IDE
Replies: 4
Views: 3474

Re: Segfault in linux IDE

This is running on a 64-bit machine: 2154 >uname -a Linux dave-w520 4.4.0-24-generic #43-Ubuntu SMP Wed Jun 8 19:27:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux I ran it under gdb and got this output: (gdb) run Starting program: /home/dhylands/openmv_v1.5/openmv-ide Program received signal SIGSEGV, Se...
by dhylands
Wed Jun 22, 2016 1:55 am
Forum: Kickstarter Topics
Topic: Value shown on outside of box was more than double the actual value of the contents
Replies: 2
Views: 9008

Value shown on outside of box was more than double the actual value of the contents

I received my OpenMV Cam shipment yesterday.

The box contained $247.70 worth of goods (adding up the items on the packing list), but for some strange reason, the box showed $617.50.

I wound up having to pay over $100 in taxes rather than the expected $47 due to that mistake.
by dhylands
Wed Jun 22, 2016 1:18 am
Forum: General Topics
Topic: Segfault in linux IDE
Replies: 4
Views: 3474

Segfault in linux IDE

I tried downloading the prebuilt openmv-ide and when I run it on my ubunutu 16.04 machine I get: 2141 >./openmv-ide Segmentation fault (core dumped) I then downloaded the source tree and got the firmware to build and flashed it. I was originally using gcc 4.9 and I got an error stating the CCM overf...
by dhylands
Sun Feb 14, 2016 8:20 pm
Forum: General Topics
Topic: Documentation on connecting?
Replies: 11
Views: 7484

Re: Documentation on connecting?

Yeah note 4 seems to be on all of the analog pins. And all it says is that FT=5v. But PA4 and PA5 are NOT FT. They're TTa. It might be worth clarifying with an STM FE.
by dhylands
Sun Feb 14, 2016 1:46 pm
Forum: General Topics
Topic: Documentation on connecting?
Replies: 11
Views: 7484

Re: Documentation on connecting?

Its worth double checking the processor datasheet. On the '405, pins PA4 and PA5 are tagged as TTa which means 3.3 V tolerant I/O directly connected to ADC (so those 2 pins are not 5v tolerant, even in a digital mode). The five volt tolerant pins are all tagged as FT in the datasheet (in the pin and...
by dhylands
Sat Feb 13, 2016 6:38 pm
Forum: General Topics
Topic: Documentation on connecting?
Replies: 11
Views: 7484

Re: Documentation on connecting?

kwagyeman wrote:Alright, I've updated the quick ref.

I didn't know this but STM32 devices all have 5V tolerant I/O pins. Nice!
Almost. The pins are only 5v tolerant when in a digital mode. When in analog mode, you shouldn't exceed 3.3v
by dhylands
Thu Aug 06, 2015 1:20 pm
Forum: Project Discussion
Topic: Using cameras on vehicle for land departure and look ahead
Replies: 2
Views: 3400

Re: Using cameras on vehicle for land departure and look ahead

My car doesn't have cameras but it does have some sideways looking radar/sonar on the rear, and I get a beeping if it detects a vehicle coming when I'm backing out of a parking space.

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