[Ovmsdev] SD CARD vs 16MB flash
casner at acm.org
Tue Jan 9 00:57:01 HKT 2018
On Mon, 8 Jan 2018, Mark Webb-Johnson wrote:
> Now finalising hardware with the china manufacturer. I think at this point, it is
> 1. Use 1 line SD CARD (which frees up GPIOs SD_DATA1/SD_DATA2/SD_DATA3, but also
> avoids the conflict between GPIO12/SD_DATA2 and VDD_SDIO bootstrap pin).
I just go with the flow on this one.
> 2. Add some capacitors for power line smoothing, as per Espressif’s example in their
> test board.
Always a good idea.
> 3. Double-check power on SIMCOM module, to ensure it is as expected (following issues
> reported with low-amperage USB ports).
As I've been testing with release/v3.0 of esp-idf, I had to disable
the brownout trap entirely. Even the lowest configured voltage would
trap repeatedly. This is with a powered hub (SIIG brand, I think
decent quality). Sometimes it seemed I could get by this by flashing
again, but when it was happening it would repeat with every reset.
> 4. Change to use Analog Lamb WROOM-32 module and their 16MB flash + 4MB ram.
Would it be feasible to add our own SPIRAM chip to use with the WROOM
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