TDK Blue5 conversion

After the apperiance of Bluetooth technology I was annoyed because companies ignored this solution for type III-Palms.
During a meeting of our PUG Hamburg, Ozei (Michael Osei-Ampu) made me start thinking of adapting a Blue5 made by TDK for type V-Palms. In the end it worked thanks to Hardy (Hardy Mlasowsky) who worked simultaneously on this for his Handera 330 and could give me some clues. His solution differed frome mine but was not bad. Refer to www.h-ml.de for this.

Generally there are two tasks to solve.
First: the plug connection to the serial port of the Palm IIIc which is different from the V-series.
Second: an external power supply is necessary due to the 3.3V pin (#2) of the IIIc is only made for HotSync button and without any electric power.
In each case you have to open the Blue5 housing and warranty will be lost! All manipulations are at your own risk!

Serial connection
At first the two notches of the Blue5 plug were cutt off. They were more of a hinderance than a help. After that I took a "Bridge"-connector (www.midwestpcbdesigns.com) and removed the housing. The remaining printed circuit board with plug was screwed with a *very* small screw (from model railway) into the plug of the Blue5 (drill first!). Be careful that the screw doesn't touch any pins! The conductor paths of the printed circuit board of course, have to touch the respective pin contacts of the Blue5. Only pin #2 (see "power supply") should not have contact to avoid an external voltage on the serial port of the Palm during usage.
This kind of connection has proved as very stabile.

An alternative solution with a cradle plug (refer to www.gpskabel.de) which was soldered "piggyback" onto the Blue5 pins and stabilized mechanically by an angular plastic bar looked much better but was too unstable. Additional to that, the soldered connections are hardly within reach afterwards.

Power supply
Here I decide to use a quatro AAA-battery housing (by Conrad Electronic) which was fastened with two tesa Power Stripes Mini to the bottom plate of the Blue5. It fits well in the width. Three NiMH-micro cells deliver 3.6V perfectly and in the fourth shaft a small switch (on/off) was placed. The wires were simply lead to the connector, passed through on the bottom and were clamped onto it (pin#2 = plus, pin#10 = minus).

You may also attach a cover if you like. The duration of the 700mAh-NiMH-cells is about 20 hours.
There are also 3.6V single cells available which allow a smaller and lighter power supply. But you will need a special charger and duration will be significantly shorter.