Hi everyone, I've been making a prototype based on a MEGA128RFA1 ('built-in' radio) and the last prototype worked fine on current consumption.
That one used a ceramic antenna, a 15k resistor between the TST pin and ground and had the AREF pin floating (also had four SPI flash memories, each with its own CS line connected to each to a different pin in the µC).
On this device, I had around 5~15µA of consumption in sleep.
Then I made some changes:
- ceramic antenna was replaced by a µFL connector.
- removed the 15k TST pin resistor (TST pin is directly connected to ground).
- and since I wanted to measure the battery, I connected the AREF pin to PF1 (ADC1) and battery to PF0 (ADC0) to measure differential voltage.
- (also in this case I'm using only one pin to control the Chip Select line on all four SPI memories, since they have a 'HOLD' pin to make them stop listening).
- this board has a different distribution, so it has some pins in the microcontroller exchanged.
In this prototype I'm getting ~1mA of consumption on deep-sleep.
So, now the question is ¿why am I getting 1mA of consumption instead of the 5~15µA?
Is it related to the AREF pin?
Is it related to the VCC connected directly to an input pin?
(Is there any configuration needed on either of those pins?)
Maybe I shouldn't remove the resistor on the TST pin? (I doubt it's this one)
I don't think is the new antenna connector, could it be?
(I also don't think it's the use of a single 'chip select' line since the memories are all disconnected when entering deep-sleep.)
If need more info I'll gladly give it to you.
Or could it be