I have 2 Xbee Series 1 non Pro. 1 is on a a Roomba with DIO 1 is connected to a NPN transistor 2n2222a that turns on and off a 8v regulator that is connected to a camera. I have a 1.5K ohm resistor between the XBee DIO and the transistor.
When the Pin on the XBee is high to turn on the transistor, the power led will blink after awhile. It only happens with the DIO is high. I setup line passing and it does the same. When I set the base to high and the remote goes high, then after a little bit the power LED starts blinking again. While it is blinking if I power down the base it stops blinking.
The transistor is only drawing 1.6-1.7ma. When the XBee starts to blink it basically shuts down. The regulator cools off so it seems the XBee has shutdown, but I can’t find a reason for it to do that. If I set the pin low on the base which sets the pin low on the remote so the LED stops blinking.
I can’t find any documentation what a blinking power LED means.
The XBee is a 3.3V device. You should not have 5V on the XBee’s Vcc pin.
Where is the POWER LED in the schematic?
How much current does the CAM draw?
When the power LED is blinking what is the voltages, 16V? 5V? 8V?
Exactly which regulators are you using? Manufacturer’s part number.
The regulators need to have caps on both their inputs and outputs else they can oscillator. See the Manufacturer’s data sheet on the regulators for suggested cap values.
I am not at home but I know the camera is 80ma no IR for night and 200ma with the IR on. The power LED is on the Parrellax adapter bored. The link has the schematic.
the 8V regulator is putting out 7.90 which is enough for the camera, it will run on less.
the 16v can be as high as 17 since it is from the Roomba battery and depends on battery level. Its the raw battery voltage.
When I get home I will check the voltages during LED blink but I know the camera turns off and the regulator cools down.
I don’t have any, what is a good value? I haven’t looked at the datasheet yet, shame on me. I was just following the pinout on the back of the packaging. I didn’t think of caps, I guess since it was thinking it was a simple regulator. Now that I think about it my Sparkfun bread board power supply has caps. I have connected to the oscope right now, waiting for it to act up. Usually it has by now, taking longer this time.
100nF and a 10uF is good to have on the regulator output. It may work with only one but both is a good idea.
Without any caps the regulator can oscillate as you saw on the scope.
Since the regulator data sheet does not specify any cap values then the values are not too critical. So the two you chose should work fine.
It is also good to have at least a 100nF cap on the regulator inputs. The smaller value cap should be close to the regulator pins.
I suggest looking at a National Semiconductor data sheet for the LM780x (LM7805). This data sheet will have much more info and recommended circuits. The NTE data sheet only has the bare minimum info and requires additional knoweledge to use these regulators properly.
Thank you so much for your help. I am going to try and finish it up tonight after work. I only added the caps to the 5V reg, might as well as add a set to the 8V reg too. I have enough in my inventory.
Now time to write a web interface
If you are interested I post all my stuff on my blog in my signature.
I am am confused! I soldered everything out permanently and it seemed worse. I added a 100nf on the input as well ceramic. It started acting up much sooner. I tired with and without some of the caps. I checked the input side with the scope and that is oscillating too. So could it be the Roomba then, or can the regulator cause the behavior on both sides?
I guess it could make sense if the higher load with the 2nd regulator on is causing the power source to have issues. Which doesn’t make sense since its supposed to be raw battery and the battery is new. I wonder if its something to do with the Roomba charging circuit which has 2 new MOSFETs in it to fix the weak ones on the charging circuit.
I should try my circuit with my own power source and see if it does it.
I am testing directly from the Roomba to test the same conditions. So far so good.
So if that is the case the Roomba still has a issue, but I could add my own connection from the battery to my circuit directly internally. That might be a good work around since it only happens with load.
Now I am testing different conditions with the Roomba, like during charging, off the dock, and off the dock and awake.
