Existing Solution:
Unitek Scope Solution
It could do 8 Channel 200ms for 2000 sample points
Hence sampling at 10kHz
Assume uint16_t for per sample
Bandwidth required: 16 * 10k = 160kbit/s
Calculation:
SD Card Speed
Max SD card speed is 120 kBps = 983040bps ~ 983kbit/s
If car is logging at 30KHz, each sample can be 32.768bits per sample (4.096per channel@8 channel)
if car is logging at 10KHz, each sample can be 98.304bits (8 Channel = 12.288bits per channel)
SD Write speed won't be an issue
SPI
Delfino SPI max clock is 40MHz
At 30kHz is about 1333.333bit per sample
At 10kHz is about 4000bit per sample
(This is fully theoretical)
Theoretically SPI Bandwidth shouldn't be an issue (Haven't consider overhead)
Concept:
Software
It it said that SD card perform better at write bigger chucks of data than smaller once, hence the buffer
Hardware
Native Delfino SD Card Logging
