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Derniers sujets
Attempt at cheap homemade...
Forum : Support and DIY (English)
Dernier message : watageek
09-14-2017, 09:06 AM
» Réponses : 63
» Affichages : 5 624
Pedal load sensor/ power ...
Forum : Support and DIY (English)
Dernier message : Normand_Nadon
09-14-2017, 12:08 AM
» Réponses : 3
» Affichages : 143
Fallbrook announces N380x
Forum : General Discussions (English)
Dernier message : Oran
09-13-2017, 07:15 AM
» Réponses : 0
» Affichages : 22

  Fallbrook announces N380x
Posté par : Oran - 09-13-2017, 07:15 AM - Forum : General Discussions (English) - Pas de réponse

Been a little slow to mention this but Fallbrook have released another new model of hub. The N380x which I have been assured does have redesigned internals not just exterior changes. More info here

Looking forward to getting my hands on one to see if I can wear it out.

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  Pedal load sensor/ power meter for auto shifter.
Posté par : Oran - 08-16-2017, 02:09 PM - Forum : Support and DIY (English) - Réponses (3)

I’ve started another thread for this one but its really part of the automatic shifter project. I’m hoping to make it capable of being a power meter but I think if I can use it as a pedal load sensor for the auto shifter I’ll be happy. It’s an experiment to see what’s possible with the cheapest parts I can get hold of. If something doesn’t work or isn’t accurate enough I’ll get a more expensive version.

It’s based on this design by stoppi71 I’ve focused to start with on a robust, metal to reduce interference and hopefully water resistant casing to house the electronics. It’s definitely going to be one of the heaviest power meters. Hopefully it will succeed where other homemade power meters are likely to fail in that they won’t last because everything is stuck on the outside of the crank.

I’m hoping to place to amplifier circuit close to the strain gauges on the crank itself in its own metal box. This will then need only 4 wires to link with the rest of the electronics in a housing attached like a third chainring.

Power will be provided, as l know it won’t be very efficient, by 2 well used Li-ion 1.5Ah cells from my old Windows phone. In one of the other compartments will be room for an Arduino Nano. The forth is a spare in case I need a larger amp circuit for example or a gyro module to measure cadence. The NRF24L01 wireless module will obviously have to be mounted externally probably just sealed in a plastic bag to start with.

[Image: MSx6iH.jpg]

The crank that I’m using has a well protected area in a corner where the strain should be quite high. To attach the strain gauges I have just used basic super glue, will probably turn out to be a bad idea. They are then sealed with a popular 2 part glue called Alaldite. On top if this I placed a layer of aluminium foil, might block interference from RF maybe, never seen anyone else do it.

[Image: TWZFer.jpg]

I choose to use 4 strain gauges in a full bridge and use 2 as temperature compensation. Partly due to limited space but also other people seemed to be doing it that way and having success. I’m wondering now if it would have been better to use all the gauges to measure strain, would get double the voltage change.

The next decision is how to wire up the wheatstone bridge. The first circuit diagram was one I found on the internet however I calculated that the voltage change across the bridge would be very small.
[Image: vewYLK.jpg]
I started with a temperature compensation strain gauge on each side of the bridge. Initial signs with a multimeter were very good, I could measure a +- 0.1mV difference just bending the crank by hand. Further investigation revealed as much drift from temperature changes as the voltage variation due to bending.

Next I rewired the bridge like this. [Image: TR7Cqb.jpg]
The no load voltage is more stable although not great but I still get the same voltage change under load. To get the correct no load voltage I have connected a resistor across one of the gauges. The amplifier circuit based on a LF353 has been set up with a gain of 3000. This is giving me a voltage output of between about  0.25V - 2.5V.

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  Imprimante USB sur routeur Zyxel EMG2926 de Videotron
Posté par : Normand_Nadon - 05-20-2017, 03:01 PM - Forum : Informatique, ordinateurs - Pas de réponse

Dernièrement, j'ai eu de gros ennuis à faire fonctionner une imprimante usb sur un routeur Zyxel EMG2926 fourni par Videotron.
Le manuel indique que c'est possible mais ne mentionne aucunement comment! Voici la solution!
(j'en ai informé le support technique de vidéotron car même eux n'en savent rien)

Après des heures de recherches, j'ai "pingné" le routeur et reçu une réponse du port Hp Jetdirect... 
Louche étant donné que ce routeur est sous Linux et aurait dû fonctionner avec CUPS... Mais bon!

Premièrement, pourquoi fare un tel truc? Pour que votre imprimante USB sans intérêt devienne soudaînement une imprimante réseau accessible de tous vos ordinateurs.

Étape 1:

Brancher l'imprimante via USB dans votre PC et installez les pilotes de manière normale.
(Je ne vais pas expliquer cette partie... Des tas d'instructions sur le sujet sont déjà en ligne)

Étape 2:

Débrancher l'imprimante de l'ordinateur et branchez le câble dans n'importe lequel des ports USB du routeur.

Étape 3:

Panneau de config, section Périphériques et Imprimantes.

Ensuite, suivez les étapes suivantes (cliquez sur les images pour agrandir):

Cliquez sur "Ajouter une Imprimante" (Add Printer)
[Image: 01.jpg]

Choisissez "Imprimante locale"
[Image: 02.jpg]

Créer un nouveau port >> TCP/IP Standard
[Image: 04.jpg]

Entrer l'adresse IP de votre routeur
(Par défaut, le Zyxel est à
[Image: 05.jpg]

Choisir Helwet Packard Jet Direct
[Image: 06.jpg]

Choisir la marque et le modèle de votre imprimante
[Image: 07.jpg]

Utiliser le pilote déjà installé (celui de tout à l'heure!)
[Image: 08.jpg]

Donnez à votre imprimante le nom qui vous plaît
[Image: 09.jpg]

Choisissez si oui ou nojn vous voulez la partager
[Image: 10.jpg]

Test d'impression
[Image: 11.jpg]

Tadaaaa! Votre imprimante est en réseau de partout dans la maison!

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