On 9/25/18 1:04 AM, Sekhar Nori wrote:
Hi David,
On Monday 24 September 2018 07:01 AM, David Lechner wrote:
Due to the electrical design of the A/DC circuits on LEGO MINDSTORMS EV3,
if we are reading analog values as fast as possible (i.e. using DMA to
service the SPI) the A/DC chip will read incorrect values - as much as
0.1V off when the SPI is running at 10MHz. (This has to do with the
capacitor charge time when channels are muxed in the A/DC.)
So you believe this is an issue with the board design rather than the
limitation of the ADC chip itself? Because if its the later, the fix
should be in the driver instead.
It is the board design. There are external 4.7k series resistors that
make the RC charge time so long.
Both of these patches mentioned have been picked up in the respective
subsystems.
Is this needed for the -rc cycle or can wait for v4.20?
v4.20
