\uD83D\uDCDA Relevant data
\uD83D\uDCD8 Background
\uD83C\uDF08 Options considered
Option 1 | Option 2 | |
|---|---|---|
Description | SD via SPI | SD SDMMC |
Pros and cons |
|
🔖 SDMMC Packet Overhead: 48 bits from host, 48 bits from SD card, 16 bits |
Estimated cost | LARGE | MEDIUM |
Protocol that FW is familiar with 
Uses a SPI port that could be used for something else✅ Action items
- Determine logging output rate
- Determine loop control rate Aidan Bowers (Deactivated) (100-200Hz)
- How much data in bytes we expect to log Dhruv Upadhyay
- SD Packet Overhead:
- Timing requirement for how long the transaction can take Dhruv Upadhyay
- Determine what factors impact SD SPI transmission rates Darwin Clark
\uD83C\uDF1F Outcome
If data rates are similar, having a dedicated peripheral opens up the board to greater flexibility in the future. It is believed that sdmmc is faster than sd using spi. The firmware development cost is unknown in both scenarios, and is estimated to be similar for both. It is known that additional firmware will not need to be written for data validation when using sdmmc. For these reasons, it is suggested that sdmmc is used.