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by David Ryan
Tue Jun 25, 2019 4:48 pm
Forum: Advanced users
Topic: System file permissions best practices
Replies: 2
Views: 414

System file permissions best practices

Hello all, I have an app running on a pi that toggles the a system led. Presently I can achieve this by: 1 - running the app as root (no bueno) 2 - Setting permissions chmod 733 /sys/class/leds/led0 (This would let anyone do it) 3- Adding the app user to root group (also no bueno) What I would like ...
by David Ryan
Tue Dec 18, 2018 6:03 pm
Forum: Advanced users
Topic: No reboot switching between client/AP mode?
Replies: 1
Views: 781

No reboot switching between client/AP mode?

I would like to be able to switch from client mode to AP and then back again without rebooting. I followed these instructions on how to set up AP mode. And I do the inverse to get back, but for the settings to take effect I need to reboot. After I run the commands listed below I can successfully dis...
by David Ryan
Thu Sep 06, 2018 9:31 pm
Forum: Beginners
Topic: Switch between AP and Client mode on Raspbian Stretch/Raspberry PI B+
Replies: 1
Views: 834

Switch between AP and Client mode on Raspbian Stretch/Raspberry PI B+

Hello all, I've found a few resources on this topic, but I've yet to find a solid solution. I was able to get into AP mode using this tutorial ; however, I was never able to get the supplied IP addresses to work properly. My connected devices were all getting 169.*.*.* addresses. I suspect the probl...
by David Ryan
Thu Sep 06, 2018 8:31 pm
Forum: Advanced users
Topic: [RESOLVED] Verifying transmission complete on Tx/Rx
Replies: 4
Views: 708

Re: Verifying transmission complete on Tx/Rx

[UPDATE] For the project I was working on I ended up moving to an RS485 with flow control hardware, but I was able to find a solution to my problem in a Node library SerialPort They have a function drain that polls the OS to see if the serial port has transmitted all of it's data It works...however...
by David Ryan
Fri Jul 20, 2018 3:52 pm
Forum: Advanced users
Topic: [RESOLVED] Verifying transmission complete on Tx/Rx
Replies: 4
Views: 708

Re: Verifying transmission complete on Tx/Rx

Thanks KnarfB!

That was the answer I was afraid of. I haven't tried (really I wasn't aware of) increasing the process priority. I'll give that a shot.

Thanks for the device suggestion. If process priority doesn't check out I'll give that a shot.
by David Ryan
Thu Jul 19, 2018 2:21 pm
Forum: Advanced users
Topic: [RESOLVED] Verifying transmission complete on Tx/Rx
Replies: 4
Views: 708

[RESOLVED] Verifying transmission complete on Tx/Rx

Hello all, I have a project that uses the Tx/Rx pins to transmit through an RS-485 chip. I'm using GPIO18 as a flow control. As it stands when I go to transmit the following sequence occurs. 1 - Calculate transmission time(ms) based on baudrate and buffer size x = f(y) 2 - Set to GPIO 18 to transmit...
by David Ryan
Fri Jul 06, 2018 8:48 pm
Forum: Beginners
Topic: Configuring WiFi setting through node
Replies: 1
Views: 627

Configuring WiFi setting through node

Hello all. I've been poking around with setting up wifi via node after not having much luck finding a good full featured library. As it stands I'm using the exec in node to run iwconfig and wpa_cli commands. After getting this working it seemed like there was probably an easier way out there so I de...
by David Ryan
Wed May 16, 2018 8:22 pm
Forum: Advanced users
Topic: Trouble getting modbus over RS485 connecting to GPIO
Replies: 5
Views: 1760

Re: Trouble getting modbus over RS485 connecting to GPIO

Unfortunately, my task is to make this work without an adapter.

I've got a USB-to-rs485 adapter that's working just fine.

I'm a little surprised there isn't a working rs485 driver out there somewhere.
by David Ryan
Wed May 16, 2018 4:39 pm
Forum: Advanced users
Topic: Trouble getting modbus over RS485 connecting to GPIO
Replies: 5
Views: 1760

Trouble getting modbus over RS485 connecting to GPIO

Hello all, I'm working with a custom RS485 adapter that I've connected to the following GPIO pins GPIO 14/8 - TX GPIO 15/10 - RX GPIO 18/12 - Direction My end goal to communicate via rs485-Modbus using Node. So far I've been able to send and receive messages via serial communications and manually fl...
by David Ryan
Wed May 16, 2018 4:09 pm
Forum: General discussion
Topic: STICKY: Introduce yourself!
Replies: 3581
Views: 139258

Re: STICKY: Introduce yourself!

Hello all,

My name is David. I work as a software engineer in US-Midwest focusing on web technologies and IoT. I'm somewhat of a noob when it comes RPi. My goal in joining this forum is to become an informed noob.

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