Mirror/ardupilot
5
0
Fork 0
mirror of https://github.com/ArduPilot/ardupilot synced 2025-01-09 01:18:29 -04:00
Code Issues Packages Projects Releases Wiki Activity

AP_Compass: workaround hardware bug in IST8310 whoami

Browse Source 
the WAI (whoami) register is writeable. Not only is it writeable, but
the written value is persistent across a power cycle. You have to
remove power for about 30s for it to finally go back to the right
default value of 0x10

this makes using WAI as a test for finding a IST8310 problematic. The
best we can do is send a soft reset which will reset it to default for
us to then check
This commit is contained in:
Andrew Tridgell 2024-04-30 17:27:32 +10:00
parent 30d3c5c9d6
commit e92c38454b
1 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
libraries/AP_Compass/AP_Compass_IST8310.cpp
View File

@ -113,6 +113,22 @@ bool AP_Compass_IST8310::init()
// high retries for init // high retries for init
_dev->set_retries(10); _dev->set_retries(10);
/*
unfortunately the IST8310 employs the novel concept of a
writeable WHOAMI register. The register can become corrupt due
to bus noise, and what is worse it persists the corruption even
across a power cycle. If you power it off for 30s or more then
it will reset to the default of 0x10, but for less than that the
value of WAI is unreliable.
To avoid this issue we do a reset of the device before we probe
the WAI register. This is nasty as we don't yet know we've found
a real IST8310, but it is the best we can do given the bad
hardware design of the sensor
*/
_dev->write_register(CNTL2_REG, CNTL2_VAL_SRST);
hal.scheduler->delay(10);
uint8_t whoami; uint8_t whoami;
if (!_dev->read_registers(WAI_REG, &whoami, 1) || if (!_dev->read_registers(WAI_REG, &whoami, 1) ||
whoami != DEVICE_ID) { whoami != DEVICE_ID) {