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by donmerch
Tue Aug 13, 2019 1:41 pm
Forum: General discussion
Topic: 'Sniffing' Serial Commands?
Replies: 25
Views: 939

Re: 'Sniffing' Serial Commands?

aBUGSworstnightmare wrote:
Sun Aug 11, 2019 1:00 pm
You should get hands on something like this https://www.saleae.com/
I'll second this. I've had several since they first came out. Best serial troubleshooting tool I've ever owned.
by donmerch
Thu May 30, 2019 2:09 pm
Forum: Python
Topic: A Pauser class
Replies: 1
Views: 543

Re: A Pauser class

Nice!
by donmerch
Sun Oct 14, 2018 2:05 pm
Forum: Python
Topic: [SOLVED]Coin Acceptor read Pulses
Replies: 71
Views: 23264

Re: [SOLVED]Coin Acceptor read Pulses

In order to get some help can you repost your code using the code tags?
by donmerch
Sun Oct 14, 2018 2:02 pm
Forum: Python
Topic: PYTHON-Interfacing Pulse sensor with raspberrypi3
Replies: 5
Views: 3263

Re: PYTHON-Interfacing Pulse sensor with raspberrypi3

You're using a ADC which converts an analog voltage to a digital value to measure a pulse? Shouldn't you be able to just connect your device to a gpio (maybe using a voltage divider) and detect/count pulse without a ADC? Or are you trying to measure some sort of voltage level?
by donmerch
Sat Jun 23, 2018 4:49 pm
Forum: General discussion
Topic: Connecting/reading a flow meter from RPi
Replies: 26
Views: 2395

Re: Connecting/reading a flow meter from RPi

Gavinmc42 wrote:
Sat Jun 23, 2018 7:34 am
For better accuracy a small micro controller can figure out the flow rate and be read via i2c at the PI's convenience.
I use 8 pin micros for this sort of stuff.
What 8 pin micros do you use?
by donmerch
Sun Jan 28, 2018 6:02 pm
Forum: General discussion
Topic: Electronic Question - controlling a Laser with a transistor?
Replies: 6
Views: 811

Re: Electronic Question - controlling a Laser with a transistor?

I would use a mosfet instead of a transistor. Much lower on resistance.
by donmerch
Mon Jan 22, 2018 7:01 pm
Forum: General discussion
Topic: 24" Touchscreen Monitor for RPi 3B
Replies: 3
Views: 3147

Re: 24" Touchscreen Monitor for RPi 3B

I see this model on Amazon ViewSonic TD2421 24" 1080p Dual-Point Optical Touch Screen Monitor HDMI. Should work ok I would think.
by donmerch
Wed Jan 17, 2018 4:35 pm
Forum: Automation, sensing and robotics
Topic: coin hopper sensor: not detecting all coins dispensed (Pi GPIO too slow?)
Replies: 8
Views: 1161

Re: coin hopper sensor: not detecting all coins dispensed (Pi GPIO too slow?)

My guess is that your Pi is not registering all the pulses. If you have access to an oscilloscope or logic analyzer you could easily prove this out. I wouldn't modify anything on the hopper till you confirm it's working as expected. By the looks of your schematic the coins are sensed by interrupting...
by donmerch
Tue Jan 09, 2018 1:18 am
Forum: General discussion
Topic: How do I setup read/write on Raspbian Stretch Lite?
Replies: 4
Views: 644

Re: How do I setup read/write on Raspbian Stretch Lite?

I found this using google... I changed to the /etc/default folder and did sudo nano keyboard and changed gb to us saved it rebooted and that fixed that problem.
by donmerch
Tue Jan 09, 2018 1:00 am
Forum: General discussion
Topic: How do I setup read/write on Raspbian Stretch Lite?
Replies: 4
Views: 644

Re: How do I setup read/write on Raspbian Stretch Lite?

Ok so this is strange... I took the sd card (16GB) with the Raspbian Stretch image (that I just used to test in the Pi) and re-flashed it to Stretch-Lite using sudo dd bs=4M if=xxxx of=xxxx and I then inserted it into the Pi and it got hung up when it came to resizing the sd card. I re-flashed it ag...
by donmerch
Mon Jan 08, 2018 8:34 pm
Forum: General discussion
Topic: How do I setup read/write on Raspbian Stretch Lite?
Replies: 4
Views: 644

How do I setup read/write on Raspbian Stretch Lite?

I have a RPi3B and when I installed the latest Stretch Lite I get errors on the Pi indicating it is read only for instance if I use sudo nano raspi-config. I also tried the latest Raspbian Stretch and it works fine. If anyone has a detailed guide how to make the Lite version read/write I'd be most g...
by donmerch
Mon Dec 25, 2017 11:53 pm
Forum: General discussion
Topic: Can we get an 64bit OS?
Replies: 85
Views: 19652

Re: Can we get an 64bit OS?

Google drive should work fine.
by donmerch
Sat Nov 05, 2016 12:34 pm
Forum: Python
Topic: Bill Acceptor Train Pulse
Replies: 5
Views: 1514

Re: Bill Acceptor Train Pulse

I did a quick Google search... https://www.google.com/search?q=raspber ... _42S5F9s7A

There might be something you can glean from there.
by donmerch
Sat Nov 05, 2016 12:32 pm
Forum: Python
Topic: Bill Acceptor Train Pulse
Replies: 5
Views: 1514

Re: Bill Acceptor Train Pulse

Are you sure you have a version Apex that outputs pulses? They more commonly use MDB serial. Yes when i talked it out with the store owner, they said it outputs pulses yet the problem is i don't know the proper code for it to read pulses. Do you have any idea or anything else i have to install so i...
by donmerch
Fri Nov 04, 2016 12:11 pm
Forum: Python
Topic: Bill Acceptor Train Pulse
Replies: 5
Views: 1514

Re: Bill Acceptor Train Pulse

Are you sure you have a version Apex that outputs pulses? They more commonly use MDB serial.
by donmerch
Thu Apr 21, 2016 6:20 pm
Forum: General discussion
Topic: WIFI WEP key not accepted
Replies: 12
Views: 10145

Re: WIFI WEP key not accepted

Thanks for posting this. Here's what helped me:

"Also there should be NO quotation marks around the hex-key."
by donmerch
Tue Feb 16, 2016 3:49 am
Forum: Troubleshooting
Topic: STICKY: WiFi Dongle Issues ? Start here !
Replies: 581
Views: 665846

Re: WiFi Issues ? Start here !

I got it to work. Found this:

Edited wpa_supplicant.conf file to this...

network={
ssid="myssid"
key_mgmt=NONE
wep_key0=mywepkey
wep_tx_keyidx=0
}
by donmerch
Mon Feb 15, 2016 9:09 pm
Forum: Troubleshooting
Topic: STICKY: WiFi Dongle Issues ? Start here !
Replies: 581
Views: 665846

Re: WiFi Issues ? Start here !

New user here. I can't seem to connect to my wireless network. I see the message wlan0:Not Associated when I hover over the icon. I have a Raspi 2 board with latest install of Rasbpian Jessie (downloaded just a couple days ago). The wifi dongle is an Edimax EW-7811UN. I can see the network in the li...

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