I’m developing custom firmware for the RAK3401+RAK13302 that has expanded storage requirements (min. 1 MByte) beyond the 28KB space exposed via InternalFileSystem.
I ordered several of these boards along with RAK15001 flash modules fully expecting to be able to use them like I do on the RAK4631.
To my dismay, I’ve come to learn that in fact I can’t use the RAK13302 and the RAK15001 together due to the unfortunate design wherein they both share the same CS pin.
I considered adding a 3rd party flash module, but again disappointed to not find the SPI bus available on any headers of the RAK19007 base board. I suppose that an I2C module would work, but I there just aren’t many options for those in 1 MByte or larger capacities.
Is there ANY way at all to add flash storage to a board also running a RAK13302 that anyone knows of?
Last thing I’ve considered is a custom sensor module with CS assigned to an alternate pin, but that’s beyond my skillset and I’m not even sure that would completely resolve SPI bus contention.
Any advice would be greatly appreciated!
Welcome to the forum @attermann
You can check module compatibility with the WisMap Tool
A potential solution would be to use the [RAK19001 Dual IO Base Board(RAK19001 | Dual IO Base Board | Multi Slot WisBlock Base Board), use one IO slot with the RAK13302 and the second slot with the RAK13002 IO Module to have SPI exposed.
But the RAK13302 already uses several IO’s (IO2, IO4, IO5 and IO6) so you have not much IO’s left to control the flash memory.
Thanks for the quick reply @beegee!
A RAK19001 looks like it could work at least to confirm that the RAK13302 and the RAK15001 play nicely together on the SPI bus when using separate CS pins before considering going further with this. I only need one extra IO for alt CS so I expect it should work.
Regarding custom modules, do you happen to have any experience with or knowledge of JLPCB or any of the other economical board manufacturers being used to build small batch custom RAK sensor modules? A module with a W25Q128 on an alternate CS pin would be very useful.
Thanks again.
Sorry, I have no experience with JLPCB. I know a few people made custom WisBlock modules, but I do not know whether they used JLPCB to produce them.
No worries, thanks for the reply.