<div dir="ltr">All Good ! I'm running on a Asus Tinkerboard with an Rockchip RK3288 (ARM Cortex-A17) which is no slouch and has onboard audio (in and out!)<div><br></div><div>I like having the four serial ports at my disposal (*grin*).<br><div><br></div><div>I've run out of Pi3's and won't be ordering any more.<br><div><br></div><div>I'm amazed that more of these boards don't have some form of LVD and shutdown inbuild into kernel, it's not that hard.</div><div><br></div><div>I should be able to do same with the Tinker as you do with Odroid.</div><div><br></div><div>I'm thinking of putting one of these in a solar site with 25W HF transceiver in the country, hence needing to have LVD. I could do same with a ATtiny84 or ATtiny1634 (<<- current favourite AVR)</div><div><br></div><div>73</div><div><br></div><div>Matt</div><div>VK5ZM</div><div><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On 30 January 2018 at 20:54, Glen English VK1XX <span dir="ltr"><<a href="mailto:glenlist@pacificmedia.com.au" target="_blank">glenlist@pacificmedia.com.au</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Matt<br>
<br>
Note for PIs, only PI3 will run the decoder decently. any sh1t will run the encoder.<br>
<br>
How fast can you get the PI off if an interrupt via GPIO comes in ?<br>
<br>
In ODROID we have a root process sitting on the IRQ. a shellscript shutdown is generated within a time slice or so....<br>
<br>
I have a TINY-13 DIL8 atmel on the board to program up to do challenge duties for the host. send a pulse, get one back etc within 3 seconds etc etc or pull power, and also it has a analog pin for looking at the input volts and starting a shutdown on another gpio pin.<br>
<br>
just need to have enough energy on board to keep the computer up for just long enough to complete a shutdown, in reality probably only needs to SYNC and UNMOUNT etc then die. if user files are left hanging the FS will deal with that next boot.<br>
the ups function adds quite a bit to the board, doign it proper.y. I'll have a think about it otherwise I'll just provide an opto input to accept a closure which will trigger the fast shutdown.<br>
<br>
Actually there are a few Raspbian crash-shutdown type SD card flavors (apart from just booting with the system partitions RO and using a USB key for /tmp log and application data.)<br>
<br>
this is how I do it<br>
<br>
send SIGTERM to the guzzling application<br>
<br>
ps kill etc<br>
<br>
#sync fs<br>
echo s > /proc/sysrq-trigger<br>
<br>
#remount in RO<br>
echo u > /proc/sysrq-trigger<br>
<br>
echo 1 > /proc/sys/kernel/sysrq or sysctl -w kernel.sysrq=1<br>
<br>
echo o > /proc/sysrq-trigger<br>
<br>
or really quick and dirty<br>
<br>
shutdown -F -h -n now<span class=""><br>
<br>
<br>
<br>
On 30/01/2018 5:04 PM, Matthew Cook wrote:<br>
</span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">
Glen,<br>
<br>
I'd also suggest the following;<br>
<br></span>
* pull the TX/RX of the FT230 into a RS232 driver to allow radio control<br>
* Have some form of H/W monostable watchdog for the Pi (mostly<br>
likely dump power)<br>
* It would also be a good idea to have some form of UPS function<span class=""><br>
where it shutsdown the Pi or disables the radio (relay?) when the<br>
supply volts are 10.5V or less (programmable ?)<br>
<br>
73<br>
<br>
Matt<br>
VK5ZM<br>
<br></span><span class="">
On 30 January 2018 at 15:36, Glen English VK1XX <<a href="mailto:glenlist@pacificmedia.com.au" target="_blank">glenlist@pacificmedia.com.au</a> <mailto:<a href="mailto:glenlist@pacificmedia.com.au" target="_blank">glenlist@pacificmedia.<wbr>com.au</a>>> wrote:<br>
<br>
Today I have done a schematic for a board to plug into either Pi<br>
or Odroid, OR any platform with a USB for the usual requirements-<br>
audio I/O , PTT, a uart and some spare pins for GPSPPS etc<br>
<br>
Before I finalize it, are there any requests ?<br>
<br>
Currently :<br>
<br>
40 pin header for direct connection of IO to Odroid or RPi for<br>
GPS/UART/PTT/RX mute / IO<br>
<br>
On board USB audio device (PCM2903) for TX/RX audio (two channels<br>
so can suit IQ radio)<br>
<br>
On board USB UART (FT230) for generating RTS for generating PTT,<br>
and gives you a 3.3V serial port<br>
<br>
On board 8-30V in to 5V DCDC converter. quiet.<br>
<br>
HW watchdog on PTT<br>
<br>
Some IO for ? (2 x analog in, 2 x uart 1 x I2C)<br>
<br>
should be buildable for $30 or less. all easy SMT sizes.<br>
<br>
the idea is you can plug USB audio , USB uart for any platform,<br>
or you can use the built in expansion header IO for PTT etc direct<br>
on a suitable board. IE good for PC or good for Odroid/PI.<br>
<br>
green pluggable header for radio interface.<br>
<br>
<br>
<br>
<br>
<br>
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