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by davethomaspilot
Tue Nov 06, 2018 12:32 am
Forum: Troubleshooting
Topic: PI 3 serial port use
Replies: 12
Views: 47737

Re: PI 3 serial port use

I switched rpis, and it's now working as expected (with the swap, haven't tried the BT-disable version yet)

Maybe the TxD output driver was damaged somehow.

Thanks for reading
by davethomaspilot
Mon Nov 05, 2018 10:42 pm
Forum: Troubleshooting
Topic: PI 3 serial port use
Replies: 12
Views: 47737

Re: PI 3 serial port use

So, that message is irrelevant. It occurs during the boot process, long before I try writing to /dev/serial0. But, I tried using a standard baud rate--no difference. It's like I'm communicating with the UART, but its TxD pin isn't on the header. I'm stuck at this point. Any suggestions on how to con...
by davethomaspilot
Mon Nov 05, 2018 10:19 pm
Forum: Troubleshooting
Topic: PI 3 serial port use
Replies: 12
Views: 47737

Re: PI 3 serial port use

I'm having trouble using the PL011 uart on RPi 3B+. I've disabled bluetooth using this in config.txt (I first tried with the enable_uart=1 before the dtoverlay line) #enable_uart=1 dtoverlay=pi3-disable-bt enable_uart=1 pi3-disable-bt disables the Bluetooth device and restores UART0/ttyAMA0 to GPIOs...
by davethomaspilot
Mon Oct 29, 2018 12:56 pm
Forum: Other
Topic: Raspberry pi 3 RTOSes
Replies: 6
Views: 6650

Re: Raspberry pi 3 RTOSes

I have a similar question. Here's my attempt to define "how realtime" my project needs. I'd appreciate any comments on how feasible it is on an RPI 3B+ running stretch. Do I need to dedicate a core? Is even that sufficient, or do I need a separate, dedicated processor? An "event queue" will exist th...
by davethomaspilot
Sun Aug 19, 2018 7:00 pm
Forum: Troubleshooting
Topic: isc-dhcp-server doesn't start unless ethernet connected
Replies: 8
Views: 736

Re: isc-dhcp-server doesn't start unless ethernet connected

Can any one explain this behaviour (dhcpcd timeout at boot)? Is it a bug in Jessie and Stretch?
by davethomaspilot
Sun Aug 19, 2018 2:58 pm
Forum: Troubleshooting
Topic: isc-dhcp-server doesn't start unless ethernet connected
Replies: 8
Views: 736

Re: isc-dhcp-server doesn't start unless ethernet connected

And, of course, the same work-around is effective on Jessie.
by davethomaspilot
Sun Aug 19, 2018 1:33 pm
Forum: Troubleshooting
Topic: isc-dhcp-server doesn't start unless ethernet connected
Replies: 8
Views: 736

Solved! (maybe)

I used raspi-config and configured to not wait for network at boot time. Now, wlan0 gets the appropriate static ip address and everything works normally. But, I chose to configure to wait for network, since an application is started which needs ethernet connection. I figured if it started before the...
by davethomaspilot
Sun Aug 19, 2018 12:42 pm
Forum: Troubleshooting
Topic: isc-dhcp-server doesn't start unless ethernet connected
Replies: 8
Views: 736

Re: isc-dhcp-server doesn't start unless ethernet connected

Upgraded to Stretch on a clone of the Jessie+my stuff image. Still same problem (no wlan0 ip address). But, the wlan0 static ip defined in /etc/dhcpcd.conf is picked up fine when there's an ethernet connection. I can see in /var/log/syslog that dhcpcd is timing out. After boot, if I start dhcpcd man...
by davethomaspilot
Sat Aug 18, 2018 9:57 pm
Forum: Troubleshooting
Topic: isc-dhcp-server doesn't start unless ethernet connected
Replies: 8
Views: 736

Re: isc-dhcp-server doesn't start unless ethernet connected

That's very painful to have to update over 40 pis in the field, unless I know that's a required solution.
by davethomaspilot
Sat Aug 18, 2018 9:52 pm
Forum: Troubleshooting
Topic: isc-dhcp-server doesn't start unless ethernet connected
Replies: 8
Views: 736

isc-dhcp-server doesn't start unless ethernet connected

I have been using rpi-3 running Jessie. I run hostapd and isc-dhcp-server. /etc/dhcpcd.conf is configure for static ethernet and wlan addresses. Everything has been working fine but I just discovered that if the rpi is not ethernet connected to another rpi, dhcpcd fails to start at boot time. I can ...
by davethomaspilot
Tue Jun 26, 2018 7:49 pm
Forum: Advanced users
Topic: Bluetooth FOB for RPI Zero W
Replies: 3
Views: 317

Re: Bluetooth FOB for RPI Zero W

A little more detail---

I'm assuming I could use something like bluetoothctl to scan for the device and make a connection.

Not sure if there's a "profile" that would be appropriate for this type of device. Maybe it would look like a serial interface?
by davethomaspilot
Tue Jun 26, 2018 7:21 pm
Forum: Advanced users
Topic: Bluetooth FOB for RPI Zero W
Replies: 3
Views: 317

Re: Bluetooth FOB for RPI Zero W

All I'm looking for is the ability to detect the button pushes. I'll be writing the app from there.
by davethomaspilot
Tue Jun 26, 2018 3:35 pm
Forum: Advanced users
Topic: Bluetooth FOB for RPI Zero W
Replies: 3
Views: 317

Bluetooth FOB for RPI Zero W

Would something like this work with an RPI Zero W? https://www.amazon.com/Bluetooth-Universal-Controller-Smartphones-Lifbetter/dp/B076RT6S7T/ref=pd_sbs_107_5?_encoding=UTF8&pd_rd_i=B076RT6S7T&pd_rd_r=3555bd96-7956-11e8-8a2a-83c3f18333a3&pd_rd_w=P3adg&pd_rd_wg=PSHsA&pf_rd_i=desktop-dp-sims&pf_rd_m=AT...
by davethomaspilot
Sun Jun 10, 2018 11:18 pm
Forum: Advanced users
Topic: Using bluetoothctl from a script
Replies: 2
Views: 3197

Re: Using bluetoothctl from a script

Thanks for the reply! I can do something similar from my Qt based application. My question is whether this is necessary. I've seen many posts where doing echo -e "select [i]mymacaddr[/i]\nconnect[i] otheraddr[/i]\nquit" | bluetoothctl was suggested. My question is whether doing it this way can be a ...
by davethomaspilot
Thu Jun 07, 2018 10:23 pm
Forum: Advanced users
Topic: Using bluetoothctl from a script
Replies: 2
Views: 3197

Using bluetoothctl from a script

When I use bluetoothctl interactively, I see this: bluetoothctl [NEW] Controller B8:27:EB:5D:F8:3C Ipad2GMA [default] [NEW] Device A4:F1:E8:B6:2E:72 Dave's iPad [bluetooth]# connect A4:F1:E8:B6:2E:72 Attempting to connect to A4:F1:E8:B6:2E:72 [CHG] Device A4:F1:E8:B6:2E:72 Connected: yes Connection ...
by davethomaspilot
Mon May 21, 2018 9:39 pm
Forum: General programming discussion
Topic: Forcing GPIO2 state after shutdown
Replies: 8
Views: 1345

Re: Forcing GPIO2 state after shutdown

Yes, if the pcb you're designing in not space constrained, that's a good rule of thumb. But, my pcb uses the space where a gpio connector would be for components. It's more space efficient using the pins near the +5 side of the header, if you need +5 anyway. I only have to loose at little space for ...
by davethomaspilot
Mon May 21, 2018 7:54 pm
Forum: General programming discussion
Topic: Forcing GPIO2 state after shutdown
Replies: 8
Views: 1345

Re: Forcing GPIO2 state after shutdown

Are you saying the gpio-poweroff overlay not work for this pin? Or, just don't know?
by davethomaspilot
Mon May 21, 2018 6:59 pm
Forum: General programming discussion
Topic: Forcing GPIO2 state after shutdown
Replies: 8
Views: 1345

Re: Forcing GPIO2 state after shutdown

Like I said in the first post, changing to a different pin would be painful. Yes, I understand GPIO2 is used for I2C (that's why I said GPIO2/SDA1). But, I'm not using I2C. Are you saying the gpio-poweroff overlay not work for this pin? Or, just suggesting I try a different pin as an experiment. If ...
by davethomaspilot
Mon May 21, 2018 5:21 pm
Forum: General programming discussion
Topic: Forcing GPIO2 state after shutdown
Replies: 8
Views: 1345

Re: Forcing GPIO2 state after shutdown

I added this line: dt_overlay=gpio-poweroff,gpiopin=2,active_low=1 to /boot/config.txt But, the pin (header pin 3, GPIO2/SDA1) still goes high after doing a shutdown. Do I have the pin number correct? I should use the BCM physical pin number? Is my expectation correct? This should result in the pin ...
by davethomaspilot
Sun May 20, 2018 11:46 pm
Forum: General programming discussion
Topic: Forcing GPIO2 state after shutdown
Replies: 8
Views: 1345

Re: Forcing GPIO2 state after shutdown

Maybe this will work... Use gpio-poweroff on a different pin. If I understand the posts I've read, Ican put a line like this: dt_overlay=gpio-poweroff,pin=6 in /boot/cmdline.txt. So, with this overlay, if I write to the pin (1 if I choose activeHigh), power will removed from all gpio? So, all GPIO w...
by davethomaspilot
Sun May 20, 2018 9:58 pm
Forum: General programming discussion
Topic: Forcing GPIO2 state after shutdown
Replies: 8
Views: 1345

Forcing GPIO2 state after shutdown

Is it possible? I'm using physical pin 3 (GPIO2/SDA1) on the rpi zero W header to control a LED. The pin is connected to the gate of a FET, so the LED is on when the pin is high. I want the LED to go off when the pi is shutdown. It would also be nice if the LED was off at power up, until my code tur...
by davethomaspilot
Wed Apr 18, 2018 8:06 pm
Forum: General discussion
Topic: Pi Zero W at higher price?
Replies: 5
Views: 661

Pi Zero W at higher price?

I'm using multiple pi zero w's in my irrigation system. I'd be happy to pay more, even more than a pi B+ for a pi zero w.

But, I can no longer buy the zeros, at any price.

Is this a "Forever" thing, or just until there is a better supply of zeros?

Anyone want to trade RPI B+
by davethomaspilot
Tue Apr 10, 2018 12:06 pm
Forum: Advanced users
Topic: Can't write to a file from udev Run+=
Replies: 17
Views: 2422

Re: Can't write to a file from udev Run+=

I found a script that uses inotify to turn off wifi when a bluetooth device connects (and vice-versa). I can hack it to execute the commands I want at bluetooth disconnect time. case $1 in start) while true do RES=`inotifywait -q -e CREATE,DELETE /dev/input/` case "$RES" in "/dev/input/ DELETE event...

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