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by mikronauts
Wed Oct 23, 2019 1:25 pm
Forum: Beginners
Topic: Strategy to use Rpi for 24 hours HQ video recording
Replies: 15
Views: 1169

Re: Strategy to use Rpi for 24 hours HQ video recording

Why does traffic analysis need to read and store the license plates? Is this a commercial/industrial/college situation or just a home learning exercise? Hello Neilgl This is actually for a scientific research project for traffic analysis being carried out in a central government organization where I...
by mikronauts
Tue Oct 22, 2019 11:16 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C Issues w/ SAMD51 microcontroller
Replies: 4
Views: 1622

Re: I2C Issues w/ SAMD51 microcontroller

Use a logic analyzer to see what is happening.

It might be a clock stretching issue.
by mikronauts
Mon Oct 14, 2019 3:31 pm
Forum: General discussion
Topic: How to use nRF24 via CH340T serial-to-USB converter?
Replies: 14
Views: 1424

Re: How to use nRF24 via CH340T serial-to-USB converter?

That would do it... the original post only mentioned the chg340 and nrf25l01, which without a uc would be an issue. spi requires a clock signal, which is NOT available on a serial port. If you look carefully at the link the OP posted, it looks like there's a pre-programmed PIC18F on there. That woul...
by mikronauts
Mon Oct 14, 2019 1:24 pm
Forum: General discussion
Topic: How to use nRF24 via CH340T serial-to-USB converter?
Replies: 14
Views: 1424

Re: How to use nRF24 via CH340T serial-to-USB converter?

if the board provides a microcontroller in addition to the chg340 usb to serial chip, it could be programmed (my first email suggested using an arduino) to do the serial to spi conversion LOL - too much disinformation floating here... spi requires a clock signal, which is NOT available on a serial p...
by mikronauts
Sun Oct 13, 2019 6:17 pm
Forum: General discussion
Topic: How to use nRF24 via CH340T serial-to-USB converter?
Replies: 14
Views: 1424

Re: How to use nRF24 via CH340T serial-to-USB converter?

spi requires a clock signal, which is NOT available on a serial port. Huh - my previous post has gone missing. Never mind - gist was as following: I think (*think*) serial here is used instead of SPI - actually adapter sends everything it received from serial to SPI relaying back all (in turn) recei...
by mikronauts
Sun Oct 13, 2019 1:22 pm
Forum: General discussion
Topic: How to use nRF24 via CH340T serial-to-USB converter?
Replies: 14
Views: 1424

Re: How to use nRF24 via CH340T serial-to-USB converter?

The nrf24l01 requires an spi port. The chg340 usb to serial adapter does not provide an spi port. Use an arduino as a usb to spi adapter, you can write code for that. Note that there are some ftdi usb to spi adapters. @clicky Thanks for your response, and I understand that it works through GPIO. The...
by mikronauts
Mon Oct 07, 2019 9:44 pm
Forum: Troubleshooting
Topic: Power Issues w/ 6 AA Batteries through Buck Converter Powering the Pi3B+
Replies: 8
Views: 651

Re: Power Issues w/ 6 AA Batteries through Buck Converter Powering the Pi3B+

using 6x rechargable AA to power the Pi and the motors is asking .. no, begging, for trouble. use the AA's for the motors, and a usb powerbank with a 2A output for your Pi Really appreciate your feedback, this is incredibly helpful! This is my first Raspberry Pi project and I am still figuring thing...
by mikronauts
Tue Sep 17, 2019 9:44 pm
Forum: Beginners
Topic: Read data from RPi using a RFID reader (RPi as a RFID tag)
Replies: 2
Views: 208

Re: Read data from RPi using a RFID reader (RPi as a RFID tag)

program a fob? TLDR: how to turn RPi into an RFID Tag (NOT reader) Hi all, I know it's possible to read RFID cards/tags using MFRC-522 or similar. But what I need is to expose information (example: public SSH) key using RFID for a small IoT project of mine (effectively turning Pi into an RFID tag......
by mikronauts
Sat Sep 14, 2019 10:33 pm
Forum: Automation, sensing and robotics
Topic: Proyect: Autonomous robot with a rechargeable batteries
Replies: 4
Views: 800

Re: Proyect: Autonomous robot with a rechargeable batteries

You really should use independent batteries for the Pi and the motors.
Brownouts often corrupt the sd cards.
by mikronauts
Fri Sep 06, 2019 1:14 am
Forum: Python
Topic: Data input from an A/V cable
Replies: 11
Views: 1078

Re: Data input from an A/V cable)

The Pi does not have av inputs.

Depending on what you want to do you may find a compatible usb video capture stick.
by mikronauts
Wed Sep 04, 2019 6:48 pm
Forum: Beginners
Topic: raspberry pi 4 and wine or x86 emulator
Replies: 23
Views: 11587

Re: raspberry pi 4 and wine or x86 emulator

Try a cheap windows tablet.
by mikronauts
Sun Sep 01, 2019 4:24 pm
Forum: Troubleshooting
Topic: RPI4 Poor Network Speeds
Replies: 16
Views: 1783

Re: RPI4 Poor Network Speeds

Yes, but ntfs is one of the first things to check. Check your wired network to make sure your pi is connected at 1000mbps. Check samba tuning parameters, and make surd your switch supports jumbo frames. Make sure the drives are not using ntfs. No, all drives are formatted as Ext4. But if the drive f...
by mikronauts
Sun Sep 01, 2019 2:27 pm
Forum: Troubleshooting
Topic: RPI4 Poor Network Speeds
Replies: 16
Views: 1783

Re: RPI4 Poor Network Speeds

Make sure the drives are not using ntfs.
by mikronauts
Tue Aug 27, 2019 2:44 pm
Forum: Beginners
Topic: Code for multiple ultrasonic sensors ROS related
Replies: 2
Views: 387

Re: Code for multiple ultrasonic sensors ROS related

You can only trigger one at a time if you expect usable result as all the triggered sensors can pick up the echo from the closes object. Hi, I have 7 ultrasound sensors (hc-sr04) on my robot wired on the raspberry pi. I wanted to write a node that would first trigger only 4 of them and publish each ...
by mikronauts
Sat Aug 24, 2019 9:31 pm
Forum: Troubleshooting
Topic: [SOLVED] PI4 USB3 Port and Logitech Keyboard Wireless Range
Replies: 13
Views: 887

Re: PI4 USB3 Port and Logitech Keyboard Wireless Range

Why on earth would you waste a usb3 port on a keyboard dongle??? So I've been setting up my new PI4 and loving many of the features. Most things working well but not my Logitech wireless keyboard :cry: I've used it with all versions of Pis over the years and no problems but now the range is really p...
by mikronauts
Tue Aug 20, 2019 1:51 pm
Forum: Networking and servers
Topic: Fast reading, very slow writing - rpi 4, samba, external USB 3.0 HDD
Replies: 3
Views: 1363

Re: Fast reading, very slow writing - rpi 4, samba, external USB 3.0 HDD

Ext4 or ntfs? Ntfs is known to be slow on a Pi. Hey guys, so I'm trying to set up my new raspberry pi 4 with an external hdd usb 3.0 with samba in raspbian. The thing is it's giving me great speeds for reading, but really slow and unreliable write speeds. Speeds: https://imgur.com/a/E59rMhs Things I...
by mikronauts
Thu Aug 15, 2019 12:37 pm
Forum: Troubleshooting
Topic: Four dead Pis in one class!?
Replies: 15
Views: 1317

Re: Four dead Pis in one class!?

Sorry to hear about your problems, however you REALLY should be using different battery packs for powering the Pi and the motors (as others have mentioned) I've built dozens of bots, and have not fried a Pi yet. I'm a relatively new raspberry pi educator (I was fortunate enough to get to go to a Pic...
by mikronauts
Tue Aug 06, 2019 6:21 pm
Forum: Graphics, sound and multimedia
Topic: Multiple VGA synced outputs
Replies: 7
Views: 590

Re: Multiple VGA synced outputs

Use two of those, on pi0w's to drive the projectors, with another pi controlling the relays and telling the 0s when to play
jamesh wrote:
Tue Aug 06, 2019 2:48 pm
Here's a cheap and cheerful VGA adapter running off the DPI pins. https://www.aliexpress.com/item/32805339645.html
by mikronauts
Sun Jul 14, 2019 1:28 am
Forum: Beginners
Topic: What wireless controller can I use?
Replies: 14
Views: 724

Re: What wireless controller can I use?

Google "bluetooth wireless controller" I want to build a bought from ground up. Four wheels, four-wheel drive. I need two joysticks, one joystick for the two right Wheels another joystick for the two left Wheels. And a few other things. I would need and knob that I can control the speed of a motor w...
by mikronauts
Sun Jul 14, 2019 1:25 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 3680

Re: Want to measure battery volts

I would suggest hiring someone with appropriate knowledge and experience to do the work. If it was a one-of for your own personal use, and you were learning, that is one thing, although still not wise without appropriate experience. If the customer wanted a one-of and was not only aware of your lack...
by mikronauts
Tue Jul 02, 2019 6:56 pm
Forum: Python
Topic: I2C lcd isnt working with multiprocessing(solved mp was not the issue))
Replies: 4
Views: 324

Re: I2C lcd isnt working with multiprocessing

Two threads (or programs) cannot access the same i2c pheripheral at the same time. Google "semaphores" (locks) and/or write one i2c server process and send messages to it from other threads. Google "server daemon" or "server thread" I have tried the lcd out of a thread in the same program, and in ot...
by mikronauts
Tue Jun 25, 2019 3:24 pm
Forum: Beginners
Topic: Raspberry pi 4 sold out?
Replies: 19
Views: 5040

Re: Raspberry pi 4 sold out?

That makes sense. 1GB .. Robots, NAS 2GB .. Educational desktop, test box 4GB .. Dev box, desktop I tend to keep a lot of tabs open, and prefer a 55" 4k tv for a monitor, or two 1080p monitors, so the dual micro hdmi with 4k looks great to me. With a USB3 SSD a 4GB Pi 4 will be a quite capable box. ...
by mikronauts
Tue Jun 25, 2019 2:34 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 945
Views: 151846

Re: Raspberry Pi 4 Thread - general discussion

Thanks, I will keep checking. Great news indeed! I ordered two boards - a 1GB, and a 2GB board, however I cannot find a 4GB board in stock in Canada, US, or UK. Please post here if you know any place eith 4GB in stock. Btw the additional i2c and uarts are great for my purposes. Last I check, the 4GB...
by mikronauts
Mon Jun 24, 2019 8:06 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 945
Views: 151846

Re: Raspberry Pi 4 Thread - general discussion

In low quantities, yes. Personally I ordered a few thousand nylon washers, nuts, screws and various height standoffs from a manufacturer for my boards. Price was ok. Shipping took a while. Did anybody complain about the M2.5 mounting holes (same as on previous models) yet? I can do that if you want ...

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