2017/04/14

Garmin Edge 810 - replacing USB + SD card board

For those riding a bit more or often, charging their 810 via dynamo hub, might observe that the USB port is a pretty weak part of the unit. After a few 10k it became bit annoying to plug in while riding. And I'm not the only one.

Since I'm not a friend of getting new stuff just because of a small worn out part I got me some spares from eBay.

So that's how you change it. I tried to get every step in a pic so you can follow disassembling and putting together again also just for cleaning purposes. It really looked a bit dirty along the sealing rubber. Ah, and don't wonder bout the screen - it just looks a bit worn but that's just the protective matte foil.

The 810 and the new board. Ready to play.

Taking off the rubber case and SD-card. Unscrewing the cover rubber of the ports.

Unscrewing all 6 screws from the back panel.

Taking apart both parts, finger nail should do the job.

This step would not be necessary but I wanted to show the whole story.

Typical connector for screens, you might know from notebooks. Push the black part on both sides gently towards the screen.

The cable now goes out of the connector easily.

Take off the rubber seal. You might want to clean it with some alcohol.

Lift the mainboard with a thin tool, needle or similar.

The mainboard has a port on the backside which connects to the USB board.

Now lift the white plug from the port, small screwdriver helps.

So far easy stuff. Now you need to disconnect both remaining cables.

280°C is absolutely enough, 260°C should be fine.

It just takes two seconds per wire.

The USB board itself is glued onto the case with some sort of black silicone.

It is not really sticking to the plastic case. So just take your time and go along the edge of the board.

You don't need to win a beauty contest.

With a thin blade you should be able to lift the board.

And there it is.

Once you have cleaned the case from the remaing black stuff check if the new board fits well.

From now it's just the same stuff backwards. I had pretty good results with clear window silicone.

It's a bit better to handle in a smaller portion.

Will be way to much.

Ready.

And that's how it's done. Before you do this side, go around along the case once before (forgot to make a pic).

After you filled the gap around the board take a Q-tip with a bit soap and form a smoth surface.

Make sure you don't build up too much material. Check along the SD-card slot and USB port, take off what's sticking in the way.

After a while the silicone should start to cure. Time to solder the wires. Depending on the silicone it can take two days until cured completely. So don't rush with putting back in service.

Plug in the cable.

Put the main board back into place, press to connect to the USB board.

Put the seal in the right direction.

Make sure it is in place.

Connecting the screen.

Easy.

Once you have connected the screen and the upper case to the board remove all dust from the screen and the glass. Demin water with a Q-tip helps.

Now put the case together.

Looks familiar.

So far, everything looks fine.

...

Bingo.


That's it. Not rocket science. Just take your time. The new connector is tight as it should be. Since it is really just the USB-connector I might try to take it off the USB board and replace that one with a new one as well. Just in case... :-)

2017/02/05

Bicycle standlight with SON Edelux II + Supernova E3 Tail Light 2

A day gives you the day and the night. So when you're busy during the day you better make use of the night too. I really like riding bike at night. There's nothing as good as cruising empty roads, passing towns and sleeping villages. People sitting inside, flickering blue TV lights behind windows, dimmed bed lights, calm and sleepy darkness. Long before daylight rises bakeries are waking up, cats and dogs are socialising.

Good lights are essential, since ever I prefer Schmidt. Best generator you can get. Whem I started travelling by bike I was bit surprised that oncoming trucks dimmed their lights before they actually could see me. It was the Edelux, still working on my black tank. On the lighter bikes I used the Edelux II as head light. Schmidt never came up with a tail light as cool as their head lights. So as long as there is nothing better desingned that the Supernova E3 Tail Light 2 I'll stick with that.

And there the confusion begins. None of the both companies ever stated anything regarding compatibility of these lights. No worries, they work excellent together. Bright ahead and behind. Only downside one might need to accept - at very low speed the tail light is blinking and once stopped it goes off. The Edelux itself will provide some standlight, but not the tiny Supernova. It does, but only if wired to the Supernova head light when it's fed by its internal supercap.

So if you bored and fancy some soldering - here you go. The Edelux is connected to the SON dynamo hub as usual. Another cable is running from the Edelux to the tail light. The Supernova got 3 LEDs, a diode for protection and 3 resistors inside its tiny housing. From the Edelux you won't get much more than the 7V.


At first we want to get rid of the flickering behaviour at low speeds. Thus we use a small capacitor eliminating the pulsing DC from the Edelux outlet. Next task is to save some energy in a supercap. They come in standard sizes, one close to the nominal 6V of the tail light is the 5,5V type. Supercaps are a bit sensible regarding overvoltage. A good way to ensure protection is charging the supercap via a fixed voltage regulator. They are cheap and come in standard sizes as well. A 5V type seems suitable. If you take a power supply (a few AA batteries will do as well) you observe that there's not much difference in illuminance between 6V and 4,5V. Just fyi - current is 70mA @ 6V, 40mA @ 4,5V and 10mA @ 3V. This leads to a setup where we charge the supercap with 5V from the voltage regulator. This will be the maximum voltage we can use for the standlight. But as mentioned before, nearby same brightness as running the Supernova directly fed by the Edelux.

The voltage regulator needs some protection from the backside, a standard diode will do the job. This is important because we also will bypass the supercap with the nominal voltage from the Edelux. The layout explains itself.



For the diodes I took some which were laying around here, think it was 2x 1N4001 and 2x 1N4148, more or less standard. Feel free to pick better suiting alternatives. First I just packed everything together an tested the setup in a small plastic bag for rain protection.






After two weeks without any problems the parts were put as close as possible together. Some shrinking tube and some hot glue and ready for its final installation. I run the cables internally in the frame, making use of the Di2 outlets. I placed this little alien in the down tube next to the bottom bracket. Some bubble wrap and you can ride cobbles without any noise ;)



It's running on two bikes so far without any problems, charged in 200...300m. Since there's no cut-off diode in the circuit it's glowing 'til the supercap is empty (>10mins).