Yesterday I had some fun riding my bike around town with a GPS-enabled OpenMoko Neo Freerunner attached to the handle bar. I bought a PDA/mobile-phone mount-kit for bikes at the PEARL online store.
The Freerunner fits in very good and there is some foam between the Freerunner and the plastic of the mount-kit, so it will not scratch it badly.
The USB and audio ports as well as the two buttons are accessible through the big holes at the sides of the mount-kit. The external GPS antenna port is accessible after lifting the Freerunner for 3mm (see photo 1 and 2):
To fixate it on the handle bar I just had to attach a small plastic strap to it.
Now I can clip on my Freerunner and with the excellent tangoGPS software installed I can ride around town to explore new roads for the Openstreetmap project.
Perhaps I am going to buy a dynamo hub and some sort of power converter that supplies my Freerunner with 5V, so I can charge it while riding the bike (have a look at this c’t article 23/2007, page 190)…
The c’t article features a step-up/down converter that outputs 5 volts and a battery charger for 4 Ni-MH cells. I suppose that you’d be only using the 5-volt supply. The circuits are available as kits from segor.de. There is also a commercial product, the JaWeTec BikeCharger.
However, I have designed a much simpler and cheaper solution that I believe should work at 500 mA (see my website) or whatever the maximum output current of the dynamo is, I don’t think that the switching regulators are significantly better. Both are limited to 500 mA.
My solution consists of a MOSFET rectifier bridge and a low-dropout linear voltage regulator that outputs 5 volts. The SMD version is about 14mm*22 mm, so it can be fitted inside the head tube, for example.
Fully charging an old Nokia DCT-3 series phone (about 1 Ah) takes about 50 km when riding at an average speed of 20 km/h.
I’m going to build a small series (5 or 10 or so) of the circuit and sell it to fellow hobbyists at about 10 EUR. It’d be nice if someone made a commercial product out of this. I’m not after money; I just would like to see bicycles being used more.
When it comes to the Neo Freerunner, I don’t know if you can adjust the charge current to 500 mA instead of 100 or 1000 mA, or if you can control the current by voltage, as per the USB battery charging specification that the Freerunner sadly does not comply with.
I’m willing to buy one of the converters. How can I contact you?
Geile Scheisse! Ich brauch auch so ein Ding. Ist das OpenStreetMap auf dem Bild?
hola geier!
Ja, im Display siehst Du tangoGPS mit Kartenmaterial von OpenStreetMap! Mit tangoGPS kann man auch super Tracks aufzeichnen und das Ganze dann nachher ziemlich einfach fuer OpenStreetMap aufbereiten.
[…] Hier eine andere Fahrradhalterung für den FreeRunner, die offensichtlich auch günstiger ist als meine :-S. Aber dafür ist dort der GPS-Antennenanschluss nicht richtig zugänglich. Hier noch die Wikiseite im OpenMoko-Wiki. […]
We have a hub dynamo solution at www.pedalpower.com.au please check it out
[…] a suitable one described in this blog post but since I had a ride planned for the next day ordering it from Germany was out of the question. […]