From 83189a85dacbd56c3aba6ef704d9dd25a85d33da Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Fri, 2 Aug 2013 20:25:26 +1000 Subject: [PATCH] l3gd20: disable the FIFO the FIFO was not gaining us anything, and was adding latency. If we use the FIFO we'd need to do multiple SPI transfers to ensure it is drained --- src/drivers/l3gd20/l3gd20.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/drivers/l3gd20/l3gd20.cpp b/src/drivers/l3gd20/l3gd20.cpp index 9b4bda0ae5..ce381807f5 100644 --- a/src/drivers/l3gd20/l3gd20.cpp +++ b/src/drivers/l3gd20/l3gd20.cpp @@ -342,7 +342,11 @@ L3GD20::init() write_reg(ADDR_CTRL_REG5, 0); write_reg(ADDR_CTRL_REG5, REG5_FIFO_ENABLE); /* disable wake-on-interrupt */ - write_reg(ADDR_FIFO_CTRL_REG, FIFO_CTRL_STREAM_MODE); /* Enable FIFO, old data is overwritten */ + + /* disable FIFO. This makes things simpler and ensures we + * aren't getting stale data. It means we must run the hrt + * callback fast enough to not miss data. */ + write_reg(ADDR_FIFO_CTRL_REG, FIFO_CTRL_BYPASS_MODE); set_range(2000); /* default to 2000dps */ set_samplerate(0); /* max sample rate */