Windows Mobile – the no-go world of Function Keys


I want to summarize the role of function keys in Windows Mobile, former Pocket PC, as I got several questions each week on how to use or enable Function keys in this or that application.

Here is a simple information about how function keys work in Windows Mobile.

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LED candle light with timer


I did a lot of research on battery powered LED candle lights circuits and code and was unable to find a time controlled LED candle light.

As I have some ATTiny13 left, I decided to use this little chip. As I want the LED to do a candle light for about 4hours and then stay of for another 20 hours, I need on timer and counter. Another timer/PWM is needed to immitate a candle flickering. But the ATTiny13 has only one timer. On the ATTiny13 you can either use the timer or PWM.

Fortunately the ATTiny has also a Watchdog timer that can be used to call an interrupt function. The watchdog runs with a separate 128kHz clock, independent from the CPU clock. The largest timeout is 8 seconds. So I need to count this 450 times to have one hour.

// watchdog interrupt
ISR (WDT_vect)

  //flash heart beat LED
  digitalWrite(LED2, HIGH);
  digitalWrite(LED2, LOW);
        bLedIsOn=0; //switch to OFF mode
        bLedIsOn=1; //switch to ON mode
}  // end of WDT_vect

The code makes the ATTiny13 sleep for another 8 seconds or light the LED. The ON phase is 4 hours and the sleep phase will be extended to 20 hours.

void loop ()
  //sleep 20 hours and work 4 hours
    digitalWrite (LED, LOW); //ensure LED is OFF
   goToSleep ();
}  // end of loop

The sequence starts with the ON phase, when power is applied. In the ON phase I measure about 3mA and in the OFF phase the circuit needs 300µA.

The circuit is documented in the Arduino code file. Running the ATTiny13 at lower clock than 9.6MHz did not change the power usage. But I switched to the 1.2MHz internal clock and disabled BOD (auto power down for low power) to get a longer runtime with two or three AA batteries.

UPDATE 2019/03/10: The wdt calculation is wrong and I changed the 450 cycles for one hour to 388. See github README for full update. The main issue is that the ATTiny13 datasheet says 128kHz but means 131072Hz and not 128000Hz and the wdt oscilator never cycles that fast but more or less at around 113000Hz.

CREDITS to all that share their knowledge, especially:

Openvpn server an Deutsche Glasfaser IPv6 only Router und

OpenVPN auf BananaPi M2 Zero W mit Raspbian

Deutsche Glasfaser Genexis Router in Verbindung mit zur Umsetzung ipv4 nach ipv6

Ich versuche hier meine Installation basierend auf den nachfolgenden Quellen zusammenzufassen.

Quellen: und

Nachfolgend sind persönliche Angaben in < und > gesetzt. IP Addressen sind in der Form durch x ersetzt. Universal Portmapper einrichten

Über die öffentliche IP6 Adresse des Servers (VPN Gateway) ermitteln. Portmapper

Bei habe ich eine Port Weiterleitung auf die öffentliche IPv6 Addresse des BananaPi (dem OpenVPN Server) und den Port 443 unter “Universelle Portmapper” angelegt.

Ich habe hier den Port 443 gewählt da dieser auch in vielen Fremdnetzen (zb Mobilfunk Netze) funktioniert. Der Standard VPN Port 1194 ist möglicherweise in dem einen oder anderen Netz gesperrt.

Ich habe einen Alias gewählt den ich mir leichter merken kann als den DNS-Namen. Ausserdem laufen auf demselben BananaPi M2 Zero W noch drei weitere Dienste. Diese sind über den gleichen Alias unter drei anderen Ports erreichbar.

In der Client.conf muss später der Alias Name und der gemapte Port angegeben werden, da die Verbindung nicht über IPv6 und Port 443 hergestellt wird. Siehe client.con Zeile:

remote <aliasname> <auf 443 umgeleiterter port>

Openvpn Server einrichten

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adsbox adsb receiver antenna rtlsdr gain

As adsbox did take too much CPU from my main server I moved adsbox to a banana pi zero w. Running Raspbian adsbox used about 200% of the 4 cores and 10% of the 512 MB headless system. That was OK for me and I wanted to extend the range of my rtlsdr antenne. I moved the antenna out side and was impressed about the exended range but nearby aircrafts did not show any more 🙁

As I want to see the nearby aircrafts, we are near düsseldorf in the landing lines and wanted the data of the aircrafts crossing the small home village 30km away from the DUS airport.

adsbox missed too much data or the rtlsdr dongle received too much signals. First I changed the adsbox call to use 4 threads for adsb decoding. That did not help.

Then I looked for the gain values to lower the reception signal strength. My rtlsdr RTL8232u supports gain values (found with rtl_test):

#Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6

I first started with 0.0 and got better nearby results but only a range of about 5km. Using 25.8 gives a range of 120km but too much airplanes (~39) and nearby losts. With the max gain I had more than 59 airplanes at a time. Finally I used 16.6, which still gives a range of 80km and ~5-10 airplanes.

Using the highest gain would give a very large range of ~250km but nearby signals get lost. And we ant to see mainly the nearby airplanes and now use a gain of 16.6.

The cpu usage is now down to 100% (quad core, so that is 25%) and the adsbox decocde threads are down to 15-25%.

rdesktopce issues

If rdesktopce has issues to connect to a Remote Desktop Server keep in mind that is only supported up to Windows Server 2008. Depending on your settings and the installed or not installed updates, rdesktopce may not be able to connect. I cannot fix this!

If rdesktopce connects to a Windows 2008 R2 server and shows only a desktop with blue background, try the following setting in Remote Desktop Session Host configuration:

Change “Security Layer:” to “Negotiate”

The same setting prevents rdesktopce to connect to a Windows 2012 R2 Server! Currently no solution for this issue.