tricking network port into thinking cable is connected

[Geofrancis]

i have a solar powered router a TPlink wr703n. and its all working nicely but i have been wanting a way of remotely monitoring when the battery is charging and discharging and i was thinking if I could make it so that when current went into the battery the Ethernet port would show up as connected and when it was discharging it would show disconnected unfortunately i have no idea on how to make this happen so has anyone any ideas?

i think all i need to do is figure out how the jack detection works then make a small circuit to mimic it

 

[RCoon]

Fudge something together with POE? This certainly isn't my speciality (rigging network ports to do things they aren't normally made for), but I do a great deal of custom networking in my workplace.

 

[Geofrancis]

Fudge something together with POE? This certainly isn't my speciality (rigging network ports to do things they aren't normally made for), but I do a great deal of custom networking in my workplace.

so you know how does the port detect a cable is connected to another device? like when you plug the cable in and the led comes on instantly. i need to fake a device with the minimum amount of parts.

 

[RCoon]

so you know how does the port detect a cable is connected to another device? like when you plug the cable in and the led comes on instantly. i need to fake a device with the minimum amount of parts.

It has to recieve blank data in the form of power (poe), or recieve packets from any source. A Lan cable tester might do it. We use them to check a cable is wired correctly. Very lower power.

 

[remixedcat]

PRTG and possibly add as sensor. I believe it has one if it is supported. I will test on my laptop to see if it has a batt. lvl sensor.

 

[Geofrancis]

It has to recieve blank data in the form of power (poe), or recieve packets from any source. A Lan cable tester might do it. We use them to check a cable is wired correctly. Very lower power.

what pins would the power have to be on for it to detect it?

i just tried a cable tester on it and nothing happened.

 

[Easy Rhino]

i have been wanting a way of remotely monitoring when the battery is charging and discharging

i am surprised it does not do that.

edit: nvm i see that your router is not solar powered by default.

 

[RCoon]

what pins would the power have to be on for it to detect it?

i just tried a cable tester on it and nothing happened.

Power is Pins 7&8 (Stripey brown & brown), data is 1,2,3&6, and then 4 & 5 are ground. Note: this is for straight cable, not crossover or any other crazy standard. CAT 5 Type B.

 

[Geofrancis]

Power is Pins 7&8 (Stripey brown & brown), data is 1,2,3&6, and then 4 & 5 are ground. Note: this is for straight cable, not crossover or any other crazy standard. CAT 5 Type B.

from some searching on wikipedia it says
A 10BASE-T transmitter sends two differential voltages, +2.5 V or −2.5 V.

so does that mean i just put 2.5v on the data pins and it should show as connected?

i am surprised it does not do that.

edit: nvm i see that your router is not solar powered by default.

the reason i use it is it only uses 0.5w of power so is very easy to power with a 22v 10w solar panel and a 5800mah 4s lithium pack.

the batteries will be mounted with 6mm foam around them to try and stop them freeing and burning.

its had so many combinations of batteries, chargers and regulators till i got to a point where it was cheap and efficient as i could make it.

 

[Geofrancis]

ok after some more goggling do you think if wired the tx pair to the Rx pair on the same port it would detect its self? then i could use something like a transistor to turn it on and off.

 

[Geofrancis]

since ever more googling didnt get me anywhere i done it the old fashoned way of stripping and old router and soldering 2 ports together and slowly cutting wires one by one till i only had 2 left. then took them off and jumped the 2 remaining wires on the port and it lit up. im pretty sure its the tx + and Rx -.

so all i have to do now is make a small relay or transistor that will bridge the 2 pins when power is going into the battery.

 

[Geofrancis]

after all that there is no way to check the port status on ddwrt

so plan B is an arduino board that im going to make into a battery monitoring station

Arduino lipllypad
2x resistor for votage devider
current sensor
thermistor to drive a TEC plate for overheat and cold protection.
sent over the network via serial and ser2net


this should give me all the read outs i need

 

[Aquinus]

Using resistors for voltage division consumes power since you're "wasting" power to heat in the resistors. It's not very efficient. Making a poor mans PWM voltage controller using a 555 timer and a transistor and an output filter cap might give you better results and more consistent power output. The other problem by using resistors for voltage control is that the voltage applied to the circuit depends on its resistance remaining constant, which electronics seldom are. Just my two cents.

 

[Geofrancis]

Using resistors for voltage division consumes power since you're "wasting" power to heat in the resistors. It's not very efficient. Making a poor mans PWM voltage controller using a 555 timer and a transistor and an output filter cap might give you better results and more consistent power output. The other problem by using resistors for voltage control is that the voltage applied to the circuit depends on its resistance remaining constant, which electronics seldom are. Just my two cents.

the router is running from a pwm but the voltage divider is so the arduio can measure the voltage. it can only measure from 0-5v on its analog input so i need to drop the maximum 22v to a maximum of 5v so i dont burn out the arduino.

http://www.ebay.co.uk/itm/400362498785?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649