I’m trying to connect 4 IR proximity sensors. These sensors hava a maximum current of 40mA each, so that would be 160mA for a combined maximum.
So i need to know if the 5V line is capable of pulling that kind of a load, or if i need to get my juice from the main powersupply, with a voltageregulator.
I want to use ADH8066 GPRS modem (http://www.sparkfun.com/products/10138 ) from sparkfun.com with FEZ RHINO. I have done some wiring via UEXT on RHINO, when i run startup procedure (setting pin low and high) I got “READY” from modem, but that’s it, no other response, just time out, when I use my cell phone to dial modem’s number it tells me that it is N/A.
Could it be some kind of limitation of current or low voltage ? Using 3V3, but minimal voltage in datasheet of modem is 3.4V.
you could always just issue the AT commands like the person in the comments on the sparkfun site does. AT should give you an OK at least… The subsequent ommands should all end up with an OK response too…
thank you for you reply. I have tried this before with loop sending only “AT” and got response on “OK” properly, but only for first one and then module stops replying at all.
Now I hooked up multimeter to see current coming in to the module, it goes from 20mA to about 70mA and then 0mA, so it appears that module get’s running and after a while shut down it self or get crashed.
Is this to the VCC in to the module? how have you got this wired - pictures might help? And to me it seems that there is more likely an issue with the device moreso than anything else - don’t suppose you have another one to try? Or have you tried it on it’s own connected to a PC or anything? (if oyu haven’t and you don’t know how to connect it, don’t just jump in and wire it up )
and where exactly did you measure the current ? If you’ve had to wire things up yourself, the pics that might be most helpful are the ones of both ends of your connector.
I would suggest then that you look at reproducing this outside the Rhino with it’s own power supply. If the module still drops its power consumption like you saw before, I’d see if someone else who has this (ie hit the sparkfun forum) can repro this on their module that they know is working. Seems very weird - plus I just realise we’ve taken this far from the original topic!