I recently ordered my friendly arm....initially it used to show a blank screen when i switched it on....But recently it stopped working and LED just blinks and i am not able to debug it....please help me out!! and thanks in advance...:)
Which position is the NOR/NAND switch in when you turn it on? Have you done anything to it, other than try to turn it on?
I tried both the configurations....I never burned a program before but i turned it on...at that time i had driver problem and i didnt touch it for some days... then recently when i turned it on the power led started flashing.....i tried to check input voltage from the adapter....everything seems fine i am not able to debug( ieven disconnected the lcd still no result)...thanks in advance for the reply!!:)
When trying to check the input voltage from the adapter, was the unit connected and turned on ? Power supply could be the problem, giving 5 volt with no current but dropping when it has to deliver current to the unit. That could explain the flashing powerled. Can you try with another power supply ? Regards, Ben
thanks for the reply Ben... I will try using other adapter from my lab...but with a multimeter i am getting the right characteristics like voltage drop across the input and the resistances....but they maybe not complete so i will check it again on a oscilloscope and see.....
I have checked in the lab it is pulsing at 5 volts.....it might be the problem will test with other supply and see whether it works....
Describe "pulsing". The voltage should be 5.0Volts +/- 0.25V (my mini2440 stops working at 4.75Volts) The plus limit is a guess, limited by LCD controller and whatever you are happy to stuff back out to any connected USB devices. The ripple under load on my mini2440 power pack is 5mV p/p. For reference my plug pack puts out 5.28V no-load and 5.13V loaded.
Pulsing in the sense that the voltage was varying between 5.27-5.58v on a multimeter. And on a oscilloscope i could see a band diagram on it!(literally) I could see lines everywhere between 2-5.7V.my ripple would have been in hundreds of mv. After that i used a battery eliminator and connected it to the circuit directly at the COM8 on the board and seems to work fine. And Thanks for the reply.