Sir,
I am using low latency data logger code posted at GitHub - greiman/SdFat-beta: Beta SdFat for test of new features . But I want to share the SPI with another device (2.7V 12-Bit A/D Converter with SPI™ Serial Interface). My requirement is to read from this ADC and log it to SD cad. But when I tie my MISO pins to share SPI, my read from SD and reads from ADC doesn't work. voltage on this Miso pin goes to some steady 3.3v, its not pulsing according to data. so my adc reads are showing 4096 (all high) and My SD cad reads are failing.This happens only when I tie MISO ins together. Is it because of clock speed issues? I understand that SD cad writes are happening at much faster rate, but for ADC this speed has to be reduced. how to solve this issue? I am using Arduino Mega and a Micro Sd Card Module to connect SD card.
Anyone from this forum has used this code?
Is it because of clock speed issues?
Most probably not. Post your complete code! And use code tags (the </> button in the editor)!
My SD cad reads are failing.This happens only when I tie MISO ins together.
Post schematics or a wiring diagram! This usually happens if the CS line of the slave isn't correctly driven. That might be an error in the code or a wiring error. As we have no clue about both we would have to guess. If both CS lines are correctly driven HIGH if not used the MISO of both must go tri-state if the interface is really for an SPI bus.
As some SD card boards are broken in this regard it's important that you provide the links to the used hardware (as the sticky note at the top of the board told you, you read it, didn't you?).