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Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@jugglingcats
I hacked in spi_device_queue_trans instead of spi_device_transmit. I got some unpredictable results at slower speeds but at 3Mhz and 4Mhz it was stable, and improved speed by about 2x. There are still big gaps though.
Attached are pics of two captures. Both are at with 4Mhz clock requested. The slower one is the current code and the faster one is using spi_device_queue_trans. Like I said I hacked it in so I don't think you could use this to send and receive data -- only send.
The faster capture shows roughly the same xfer (40ms) as software SPI so should be possible to improve on it.
I think ultimately the Espruino calling code should be changed to support multi-byte transfer. Faster updates should then be possible, thus providing more time between updates for Espruino/game code. For some scenarios the fact that spi_device_queue_trans is non-blocking might be useful - not sure it is for regular apps though as you generally want to wait for flip() to complete.
Anyway hope this is useful / of interest!
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