RS-232 interface

[rconaway]

Does that bullet have an RS-232 Interface?

[WHT]

There's a four pin header...haven't played with it yet to see what it does.

[UBNT-Mike.Ford]

Hey Guys,

That 4 pin header is the serial output/input.

Thanks,

Mike

[rconaway]

So if anyone wants to work on a contract where we put a switch connected on that port and then modify the firmware to monitor the port, let me know.

[WHT]

Post the advantages and features of being able to monitor the port. That might attract some attention.

[rconaway]

Good point. Basically if a simple NO or NC switch can be attached, you can monitor a door opening, water levels, etc... I can do this with a more expensive solution through B&B but with the quantities I need, it makes the project too expensive.

[WHT]

Mebbe a synch'ed shiift register for multiple control and monitoring, i.e. both way control.

[rconaway]

I was looking at something simple and cheap like pulling a line to ground for example.

[WHT]

To paraphrase Mr. McGuire (advising Ben) in "The Graduate"...

"I have one word...accessorize (add more functionality)."

[kijoma]

General purpose IO is something i would ask for too, it makes life easier if there was even a couple of Digital I/O's that could be used to switch batteries, monitor levels, detect tamper etc..

they wouldn't need to be analogue as say a V to F converter could be used for analogue stuff.

I am guessing the signal LEDs go to GP I/O pins, any left?

[rconaway]

Good question. However, that would take a redesign. I'm trying to find something that would be cheap that could be connected to the serial interface. I do like the idea of tapping the lights. I just can't think how to get that as an input.

[WHT]

Here is what someone else posted

http://telecomanddata.com/NS5_power_save.jpg

http://telecomanddata.com/NS5_power_save_relay.jpg

[rconaway]

Pretty cool. This let's you control a swith, not sense one. I would be interested to know what command he uses to control it but it doesn't solve my first problem. It does however, give me more ideas for another project. Thank you.

[kijoma]

hi,

i would guess he uses the signal level entries as a switch.. 99 on 1 off etc..

[rconaway]

I'm a doofus. I should have looked closer. It's brilliant. It just hit me that all I really have to do is kill power to the unit. Since I can do constant pings, if I kill power to the unit or put the power line through the switch, I'm golden. It's not the best way to do it but it's simple and cheap. The only drawback is you have to make sure you can get clean pings everywhere or have some delay buffer like 10 seconds. Thanks WHT.

[Ahmad]

can i use the serial port of Lite_Station to control any Hardware?

[WHT]

Its more of a serial port to control the unit, not to pass control to other devices.

[rconaway]

Should work both ways though. I asked Mike for the data and he said it was coming. I told him so was Christmas. Christmas beat him.

[videolarm]

you could also add any ip cameras to your wireless
view the location but also have the contact closures at your disposable
kill to birds with 1 stone :shock:

[rconaway]

Too expensive and too much bandwidth. We are looking at several thousand per city on average.

[ngds]

This would be interesting to monitor remote solar powered systems, would just need a little circuit to monitor voltage and dump the output to the serial port.

[rconaway]

For that application, you can get in I/O interface from B&B electronics. I could too but I need something less expensive. The easiest would be to simply see if DTR is high or low assuming there is one although I could probably do that on any line.

[WHT]

<sigh>...I guess all have to spend some Sunday afternoon whipping out a Basic Stamp I/O interface with a dozen I/O port for this project.

[rconaway]

Even the basic stamp is out of budget for this project. It has to go cheaper than that. I'm not saying there isn't an app for that but not on the project I'm looking at. Let me see what Mike has in the data specs. This gives me time to go through the SDK.

[jsharper]

how about just tying the Tx and Rx lines of the serial port to the switch. If the switch is closed, you get loopback. So, send a character out the serial port and listen. If the switch is open, you get nothing. if it is closed, you get your character back.

[rconaway]

great idea. Thank you.

[jesterz]

Anyone:

Question: Could you use that serial port to access say a PLC? If I could gain access to that port to send Modbus over TCP that would be the killer ap with OpenMesh for my AMR project. It would bring the cost down per station from approx. $200 to $70 bucks... :shock: That would be awesome!! Anyone want to work up some OpenMesh flavored firmware? Management has OK'ed a development budget... Email me about it if you are interested...

[WHT]

Even the basic stamp is out of budget for this project. It has to go cheaper than that.
http://www.arduino.cc/en/

http://todbot.com/blog/2006/09/25/arduino-the-basic-stamp-killer/

[rconaway]

This is very cool. Thanks. That gives me another option.

[oys]

Hi!

I can help you customize the firmware so that you can use the serial port as a NC/NO sensor.

To do this, you need a script constantly sending data on to the serial port's TX-pin. Then connect the TX-pin to the RX-pin with your circuit in the middle.

Then have a script listen on the serial port's RX-pin. As long as we're recieving data, the circuit is closed.

I've been working on the same thing for a personal OpenWRT project where I want to monitor a motion detector for a rapidly deployed security system.

If you need help implementing this and integrating it for your specific use, I am available for consultancy.

[raytaylor]

I envision 2 port modes

Trip mode - using external circuitry, it can connect / join the 2 required pins
Action could be writing to a log stored within the unit and showing a status
such as a red / green box somewhere in the web interface
and / or sending an http post to a website

This would be ideal for checking the battery voltage at solar sites - once the voltage lowers to a certain amount, an external relay circut closes the loop and the bullet sends a http post to a webserver. A monitoring screen can be set up somewhere to show each repeater and battery status.

Other mode i reckon would be good is a remote control function to trip a relay and control something by sending an http post without needing to login or using the web interface with a different user level to change the setting. Could be good for rebooting a webcam that doesnt support rebooting on ping fails.
Or turning on water pumps etc.
I could easily write a simple web page application where someone could click on a button and turn on a water pump / open a gate or something else all controlled by bullets and some really simple relay circuits.

[oys]

Brainstorming:

My requirement are a cheap wireless device able to control as many switches/leds/relays as possible without having to solder anything or make any other time-consuming modifications. I have been using OpenWRT with various wireless routers (including the Ubiquiti bullet and Nanostation) to make this possible.

The cheapest way I have found so far is to use the serial port to sense a single switch. By sending data on the TX pin and listening on the RX pin I can determine if switch in between is closed. This works well and I have tested it.

I was wondering if it would be possible to connect RX-Switch-3.3v and then read from the RX-pin to see if the circuit is high and or low. This would leave the RX port available for the following circuit:

To control an LED/Relay it would be nice if it is possible to wire GND--LED/Relay--TX and set TX to high/low to turn the relay or LED on or off. I don't think it is possible to set TX high directly, but I read about a project that did something similar via a 555 timer IC. If anyone knows if this can be done easier, please elaborate. This would allow a serial port to control and sense at the same time.

The Nanostation and Locostation come with ClearToSend/RequestToSend pins. To sense a switch wire VCC-switch-CTS, and to control a relay/LED wire GND-LED-RTS. I haven't tried this yet (as I only just discovered that these pins are available), but this would be a very good cheap solution. Unfortunately As far as I know, the bullet doesn't have these available. It would be nice with an overview over which products have what pin outs.

Another option is to use sensors connected to a 1-wire bus. This gives almost endless I/O's as well as the option to use various 1-wire sensors. The easiest and most reliable way to do this would be with an adapter on the ttl rx-tx pins but I it requires 5v power which is not available on most Ubiquiti devices ( think).

I think an other option would be to connect a 1-wire bus to a gpio (by re purposing one used for a signal strength led) but I haven't tried it.

Other things that have crossed my mind are using an arduino (too much manual labour), re purposing the gpios used to controll the signal leds (cheap, but soldering involved), using a weederboard via serial (about 70$), using a phidget board via usb (of course not possible on bullet, about 80$), or using an ethernet/io adapter like the iobridge (100$).

[WHT]

My Arduino project is on the back burner for a few months.

[oys]

I just had another thought: As I am only using the wireless networking interface, it should be possible to use the ethernet port in a similar fashion as I've been using the serial pins. This would mean I don't even have to open the device.

By attaching a switch between tx and rx on the ethernet plug, I can check to see if I have connectivity. Haven't quite worked out how I would be able to control a relay from this but it should be possible.

[rconaway]

Taking that Cat-5 idea further. I"m thinking an web-server chip like the SC1X. Can't find pricing on it on the website.

[Ashgar]

Hi!

I can help you customize the firmware so that you can use the serial port as a NC/NO sensor.

To do this, you need a script constantly sending data on to the serial port's TX-pin. Then connect the TX-pin to the RX-pin with your circuit in the middle.

Then have a script listen on the serial port's RX-pin. As long as we're recieving data, the circuit is closed.

I've been working on the same thing for a personal OpenWRT project where I want to monitor a motion detector for a rapidly deployed security system.

If you need help implementing this and integrating it for your specific use, I am available for consultancy.

hi
I want to read the temperature of remote area using lm35 temperature sensor with pic16f877 conected to serial port of nano ststion. I want to use nano ststion as data link. at the other side i want to use pc with vb.net program to display temperature reading.
can you help me about this project?
thanks