Instead of performing a bitwise shift operation on every GPIO read/write. Do it at compile-time and use bit mask instead.
The pin number itself is not used anywhere.
The change saves 108 bytes of flash memory
Before, the axis limits had an error of 25° so 225° would actually be measured as 250°.
Now after fixing axisUnitToTruncatedUnit to return a more accurate value, the new values are lower. Adjust the distances by 20° to offset previous error.
When converting 800mm/s2, it would be truncated to 795mm/s2 for the pulley. This is due to cutting out significant decimal digits.
Instead let's multiply in floating point, this needs quite a bit of resources. So to optimise against this, multiply with the recoprical. Then the cost is not more than 20 bytes.
Testing:
M707 A0x0e; Read Pulley Acceleration (default at boot up is 800mm/s2)
M708 A0x0e X790 ; Set Pulley Acceleration to 790mm/s2
M707 A0x0e; Read Pulley Acceleration (should be 790mm/s2)
The results before this commit:
M707 A0x0e -> returns 805
M708 A0x0e X790 ; Set Pulley Acceleration to 790mm/s2
M707 A0x0e; returns 795
After this commit:
M707 A0x0e -> returns 799
M708 A0x0e X790 ; Set Pulley Acceleration to 790mm/s2
M707 A0x0e; returns 789
NOTE:
axisUnitToTruncatedUnit is used in Idler homing, selector homing, and pulley positioning. I am not sure yet how this improvement will affect those areas.
When reading or setting the value, the driver is expecting steps_t which is a axis scaled value.
This increases the memory footprint quite a bit. But now if you set 800mm/s2, you should get a similar value back.
Flash: +132 bytes
SRAM: 0 bytes
The read operation now returns the actual used value instead of the maximum allowed acceleration value.
Change in memory:
Flash: + 78 bytes
SRAM: 0 bytes
AxisDistance returns uint16_t type and is currently compared with long double axis length. The axis lengths fit easily into uint16_t:
selectorLimits.lenght = 75
idlerLimits.lenght = 225
Change in memory:
Flash: -122 bytes
SRAM: 0 bytes
This commit produces the same savings as the compiler options -fshort-enums. Except by setting the types manually we save also 2 bytes of SRAM.
By default, the enum type is 2 bytes, with we can explictly set it to one byte when applicable to reduce code size.
Almost all the savings from from 'enum Mode' in leds.h.
Change in memory:
Flash: -116 bytes
SRAM: -2 bytes
D.R.racer
Guðni Már Gilbert
3d-gussner
Alex Voinea
VintagePC
Daniel Čejchan