Cheap wireless router + spinneret?
prof_braino
Posts: 4,313
I am using the iphone as an interface to the spineret with telnet and web-browser. This works nicely, now I want the embedded application to run untethered.
Instead using the LAN from the shop, I am thinking about putting a cheap wireless router in the robot with the spineret and running it off a battery pack. The result would be a very small network, consisting of one wireless connection to the iphone, and one wired connection to the spineret. Anyone try this?
Also, I think I read that a large part of the power consumption on a router is due to wired Ethernet. Since the distance will be very short, (about 5 inches) is there a hobbyist-simple way to reduce the power on the wired Ethernet?
Instead using the LAN from the shop, I am thinking about putting a cheap wireless router in the robot with the spineret and running it off a battery pack. The result would be a very small network, consisting of one wireless connection to the iphone, and one wired connection to the spineret. Anyone try this?
Also, I think I read that a large part of the power consumption on a router is due to wired Ethernet. Since the distance will be very short, (about 5 inches) is there a hobbyist-simple way to reduce the power on the wired Ethernet?
Comments
http://www.newegg.com/Product/Product.aspx?Item=N82E16833156262&Tpk=TEW-654TR
I don't know the power requirements, but it can be powered over USB so that should put it at 5v and under 500 mA. Since it's only got one wired connection, you are not supporting a full switch.
http://www.newegg.com/Product/Product.aspx?Item=N82E16833156327
But a power over USB option is interesting. I don't plan to use a PC at all, but I'm guessing that powered by USB means it uses the USB cconnection to also provide network accesss and does not need a regular ethernet cable (and thus saves the ethernet specific power)? So, does this mean instead of spineret, a regular prop with USB host support would be the method?
The power from USB does not need to come from a USB data connection. It has a cable with two (I missed this before) USB plugs going to a single barrel connector that plugs into the router. It is only getting power, no data.
It does use a normal ethernet cable for the router/device connection.
The reason I brought up USB powered is because that tells you that it has a 5v input (which USB puts out) and also gives you an idea about the current required. You don't need USB at all to power it - just a 5v supply with a small barrel plug.
USB will give a maximum of 500mA (by spec) so two plugs would seem to imply that the device may need up to 1A. But, if I recall correctly USB is only supposed to give 500mA if the device properly enumerates and identifies itself. If it doesn't, then it only gets 100mA (?). I'm not sure about this.
So, the device may need 1A or it may need 200mA (or less, or anywhere in between).
You can get small routers like the one you linked to and I've seen numerous robots using similar ones. But most routers and switches seem to get pretty warm. A lot of the power going into them is coming out as heat. I don't know if the travel router I linked to is any better or not.
From the specs..
Power Input 15V DC, 1A. External Power Adapter
Ouch! That's a good bit power to haul around portable.
OBC
I was wondering if there is a straightforward way to hack a router and eliminate ethernet driver, and connect directly to the prop?
I'm thinking of the way we do a direct serial connection between two props eliminating the MAX232 chip.