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by Joel_Mckay
Sun Mar 17, 2019 4:06 am
Forum: Troubleshooting
Topic: Sources.List - managed to mess it up while trying to download OpenCPN
Replies: 3
Views: 431

Re: Sources.List - managed to mess it up while trying to download OpenCPN

We do demos with openCPN 4.99 using the rtl-sdr AIS path-plotter plug-in (you would have to download the charts for your area):
https://sourceforge.net/projects/microm ... pberry-pi/

It would be great if a better repo version is available. =)

Cheers,
J
by Joel_Mckay
Sat Mar 09, 2019 2:59 pm
Forum: Automation, sensing and robotics
Topic: New Project with relay and sensors. Help needed.
Replies: 1
Views: 298

Re: New Project Help

In general, for safety reasons people tend to separate machine control loops into smaller/simpler micro-controllers, and send messages from a host running more complex software. There are Programmable logic controller (PLC) that are designed for industrial uses, but the Pi is intended for consumer g...
by Joel_Mckay
Fri Mar 01, 2019 5:29 am
Forum: Troubleshooting
Topic: RASPBERR PI IS NOT BOOOTING
Replies: 5
Views: 413

Re: RASPBERR PI IS NOT BOOOTING

Did you insert a cable while the device was running? On the Pi, I found one can't even get away with hot-plugging USB devices sometimes without causing it to reboot. Note, other plugs are not like USB, and can brick the hardware if hot-plugged. ;-) Disconnect the power, remove the camera cable, and ...
by Joel_Mckay
Wed Feb 27, 2019 9:16 am
Forum: Automation, sensing and robotics
Topic: Control multiple steppers with pigpio wave chains
Replies: 5
Views: 1205

Re: Control multiple steppers with pigpio wave chains

While this works, I am now of the opinion it is *much* easier to use much more advanced controller chips, like the trinamic chips, as this provides more advanced controls and functionality while making the code on the pi side pretty trivial If you are addressing the chips over the serial protocol, ...
by Joel_Mckay
Wed Feb 27, 2019 6:39 am
Forum: Troubleshooting
Topic: SD Cards not working- except one bought with Raspberry PI Zero.
Replies: 2
Views: 149

Re: SD Cards not working- except one bought with Raspberry PI Zero.

F3 is one of the few 100% guaranteed capacity/status verification methods: https://fightflashfraud.wordpress.com/ I wrote up a page on how to compile, install, and run F3 from the pi: http://www.micrometer.xyz/cdn/node/78 It will detect most fakes and damage, but not rebranded older slower cards wit...
by Joel_Mckay
Wed Feb 27, 2019 6:22 am
Forum: Graphics, sound and multimedia
Topic: Using two Pi's to overcome the one camera limit
Replies: 3
Views: 510

Re: Using two Pi's to overcome the one camera limit

You could, but have two limitations: 1. Both cpus must have an accurate concept of global time down to 1/60 second 2. The image capture sync will be off up to +-1 frame depending on the cameras relative latch-out buffer event-time mismatch Thus, you need to have a frame-rate of at least twice the in...
by Joel_Mckay
Wed Feb 27, 2019 4:26 am
Forum: Advanced users
Topic: RPI 3A+ or RPI 3B+ for PARALLEL COMPUTING?
Replies: 2
Views: 374

Re: RPI 3A+ or RPI 3B+ for PARALLEL COMPUTING?

OpenCL is still not fully supported by the Pi... but people are working on a port. ;-) It could in theory make the RPi 3B+ 5 to 27 times faster for some problems by adding the full capability of the GPU. However, for parallel-heavy problems you are probably still better off using an Intel i7 CPU, an...
by Joel_Mckay
Wed Feb 27, 2019 4:03 am
Forum: Automation, sensing and robotics
Topic: Setting up MLX90640
Replies: 6
Views: 8084

Re: Setting up MLX90640

In general, you need to setup the pi kernel overlays and modules to allow port access. We maintain a OverlayFS based desktop for our local CNC/3d-printer club, that already has these enabled (we played with the Lepton FLIR modules at one point) along with the recent libraries: bcm2835 libi2c-dev lib...
by Joel_Mckay
Wed Feb 27, 2019 3:20 am
Forum: Automation, sensing and robotics
Topic: Control multiple steppers with pigpio wave chains
Replies: 5
Views: 1205

Re: Control multiple steppers with pigpio wave chains

Our group builds photo-plotters, uses many CNC platforms, and runs the RTLinux kernel: https://sourceforge.net/projects/micrometer-cnc-on-raspberry-pi There are a few issues one may encounter with how you are trying to build your project. There are several people who publish Pi direct-gpio based NC ...
by Joel_Mckay
Sun Feb 24, 2019 11:01 am
Forum: Automation, sensing and robotics
Topic: Choosing motors
Replies: 36
Views: 5642

Re: Choosing motors

Post #2, stepper motors with gearboxes for £1.54? How physically small, how much torque possible from them? I'd be interested to know for future projects of my own. Modding the 5v version of the $1.60 28BYJ-48 for the more powerful bipolar mode is easy, and allows on to use current-regulated Pololu...
by Joel_Mckay
Sat Feb 23, 2019 2:11 pm
Forum: Automation, sensing and robotics
Topic: Choosing motors
Replies: 36
Views: 5642

Re: Choosing motors

You probably could use $2 stepper motors with gear-boxes for such a small platform (700g/cm). This would allow you to easily keep the two wheels on each side synced while moving. However, you may want to think about the zero turning radius a normal turtle-bot platform gets with only 2 motors (have a...
by Joel_Mckay
Sat Feb 23, 2019 1:46 am
Forum: Troubleshooting
Topic: I tried many GSM modules with RPI 3B+ but no response
Replies: 5
Views: 815

Re: I tried many GSM modules with RPI 3B+ but no response

What i want to do is to control my raspberry pi using sms or by calling the raspberry what you reckon is the easiest and best solution for this and please provide me with the name of the chip so i can use it You will need to match a USB or Mini PCIe device with your country specific carrier bands a...
by Joel_Mckay
Fri Feb 22, 2019 3:12 am
Forum: Troubleshooting
Topic: I tried many GSM modules with RPI 3B+ but no response
Replies: 5
Views: 815

Re: I tried many GSM modules with RPI 3B+ but no response

The sim900 is a GPRS / GSM G2 modem, and most places have already deployed LTE. A normal GPRS connection is impossible if you live in a place that has already deprecated GSM services. The modem-manager also has a plugin specific to cellular modems, and it can be easy to setup connections if you purc...
by Joel_Mckay
Thu Feb 21, 2019 3:20 pm
Forum: Automation, sensing and robotics
Topic: Installing OpenCV 4.0 in RaspberryPi without virtualenvironment.
Replies: 6
Views: 3696

Re: Installing OpenCV 4.0 in RaspberryPi without virtualenvironment.

Native builds on the pi are slow (must use the single instance of make ), but tends to allow better environment detection of platform specific flag optimizations. The packaged opencv versions are usually older stable generic-armhf snapshots, and your make scripts will need to account for the custom ...
by Joel_Mckay
Thu Feb 21, 2019 12:53 pm
Forum: Advanced users
Topic: 3G in raspian
Replies: 3
Views: 572

Re: 3G in raspian

Most countries have gone LTE, and thus use region specific certified hardware. In the old G2 network there was global GPRS coverage due to the standard limited set of GSM/HSPA bands, and the way networks handled data connections. Today, there is currently no longer universal coverage for G3/G4, and ...
by Joel_Mckay
Thu Feb 21, 2019 3:22 am
Forum: Troubleshooting
Topic: Can't connect to pi3 b+ from other computers on LAN
Replies: 5
Views: 333

Re: Can't connect to pi3 b+ from other computers on LAN

Try:
sudo ufw disable
.
Make sure your host OS firewall rules allows connections to other LAN hosts (Win10 may require manual tweaks).

Also check if your router has an option that allows cross forwarding traffic from wifi-to-LAN, and or disables host-to-host in-zone connections.

Cheers,
J
by Joel_Mckay
Thu Feb 21, 2019 3:12 am
Forum: Automation, sensing and robotics
Topic: Sensor to detect Vape smoke
Replies: 4
Views: 1400

Re: Sensor to detect Vape smoke

Any sensor that can see VOC should show a relatively large ppm count increase from many aromatic hydrocarbons.
I haven't personally tried the bme680 yet, but the CCS811 does seem to work rather well.

Cheers,
J
by Joel_Mckay
Tue Feb 19, 2019 10:49 pm
Forum: Troubleshooting
Topic: RPI 3 b+ don't boot after reboot and stop working after an hour
Replies: 8
Views: 3061

Re: RPI 3 b+ don't boot after reboot and stop working after an hour

Sounds like worn out flash... do the S3 scan after reformatting the disk to make sure. Please document the card brand, model, and retail source for other users. Many people have similar issues if they didn't' buy the card from a reputable source, use the wrong type of memory, or overclocked beyond n...
by Joel_Mckay
Sun Feb 17, 2019 1:23 pm
Forum: Automation, sensing and robotics
Topic: Installing OpenCV 4.0 in RaspberryPi without virtualenvironment.
Replies: 6
Views: 3696

Re: Installing OpenCV 4.0 in RaspberryPi without virtualenvironment.

This should get you on the right path:
https://solarianprogrammer.com/2018/12/ ... -raspbian/

Hint: run a native build on the pi, and ignore the cross-compiling part of the instructions.
;-)
by Joel_Mckay
Sun Feb 17, 2019 1:19 pm
Forum: Graphics, sound and multimedia
Topic: Bulletproof, lightweight video camera app
Replies: 5
Views: 4848

Re: Bulletproof, lightweight video camera app

You mean like sudo apt-get install cheese for webcams or like the common:
mplayer -fps 1 tv:// -tv driver=v4l2:device=/dev/video0:width=320:height=240
( http://wiki.raspberrytorte.com/index.ph ... r_a_Webcam )

Did you really try google before posting? ;-)
by Joel_Mckay
Sun Feb 17, 2019 5:14 am
Forum: Troubleshooting
Topic: Overheating SD Card - Smoke
Replies: 2
Views: 596

Re: Overheating SD Card - Smoke

Expanding on what HawaiianPi has already stated: there is a huge counterfeiting problem from most online re-sellers, auction sites, and community message boards. I would recommend looking at how to use S3 scans, and also dump the card firmware date code & device id information from your new cards.. ...
by Joel_Mckay
Sat Feb 16, 2019 1:44 am
Forum: Automation, sensing and robotics
Topic: Any advice for a pi beginner looking to create a control system on the pi?
Replies: 1
Views: 346

Re: Any advice for a pi beginner looking to create a control system on the pi?

Most cars have ODBII, but motorcycles never really standardized their CAN bus interfaces. This means you are often having non-fun decoding the proprietary system status/diagnostic messages if you want access to sensor data. Note most vehicle manufacturers will never share this information with third...
by Joel_Mckay
Fri Feb 15, 2019 2:27 pm
Forum: Troubleshooting
Topic: RPI 3 b+ don't boot after reboot and stop working after an hour
Replies: 8
Views: 3061

Re: RPI 3 b+ don't boot after reboot and stop working after an hour

An S3 scan is one of the few ways to detect a failing-card that no longer can reliably modify the contents of a sector. http://www.micrometer.xyz/cdn/node/78 You may be lucky and miss a damaged area... but may also still encounter random bugs. Have a look at the kernel settings we use to prioritize ...
by Joel_Mckay
Fri Feb 15, 2019 11:41 am
Forum: Automation, sensing and robotics
Topic: High reliability, high accuracy temperature/humidity sensor
Replies: 11
Views: 3983

Re: High reliability, high accuracy temperature/humidity sensor

True 1-wire is pretty reliable on the Pi. The DHT sensors use a different single wire interface. If you read the datasheets you should notice that they do not mention 1-wire anywhere. True, the example DHT polling libs are usually more likely to have timing issues being invoked from user-space... b...
by Joel_Mckay
Fri Feb 15, 2019 6:14 am
Forum: Troubleshooting
Topic: RPI 3 b+ don't boot after reboot and stop working after an hour
Replies: 8
Views: 3061

Re: RPI 3 b+ don't boot after reboot and stop working after an hour

If you are using a write heavy program the flash may wear out prematurely. SLC flash is still manufactured, and is good for over 100k writes. MLC ("Sandisk ultra", and most others) flash about 10k writes. TLC are only good for under 5k writes, but in my experience can be under 1.4k writes. Most USB ...

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