Maslow Firmware Version 0.94

Firmware version 0.94 includes even more brilliant contributions from @krkeegan. In the past we have had issues with something called "quantization noise" at low rpms. Basically what's happening is that when the motor is turning at low speed it hasn't moved very far in the 10ms window at which we measure the speed (say 20 encoder steps). Even if the motor is turning at a constant speed, this value can jump back and forth between say 20 and 21 steps which makes the controller think that the motor speed is changing. @krkeegan's approach has been to use the number of microseconds between pulses instead of the number of pulses per 10ms at very low RPMs. Brilliant! 👍 👍

#320 Fix Error in Quantization Buffer; Allow RPM to Approach 0 2 days ago
#319 Configurable Loop Timing; Improved Movement Loop Timing; and Debugging 3 days ago
#318 Improvements For Low RPM Speed Calculation 7 days ago

Maslow Firmware Version 0.93

This week includes another strong showing of new features from @krkeegan

This week he's added support for non-standard z-axis pitches (reverse direction now supported), added support for coordinated movements in all three axis at once, and cleaned up some code and removed unused variables which were giving us compiler warnings.

#317 Fix Movement of Z Axis for Non-Standard Pitches
#315 Enable 3D Linear Movements for G00 and G01
#316 Fix Compiler Errors; Remove Unused Variables and Functions

Maslow Firmware Version 0.92

This week we saw some MAJOR contributions from @krkeegan with the addition of the improved PID control system. The new system makes a number of significant improvements. In @krkeegan's words from the pull request this version makes a number of changes/improvements which include:

• Removing the running average on the input to the PID velocity calculation (this caused oscillations and damped the control reaction and I think averaging is an incorrect solution in control theory anyways)
• Adds a minimum rotation rate for the velocity controller (the motors are unable to turn at this rate, so this only caused integrator windup and noise)
• Ensure that position requests are equal to a whole number of encoder steps (prevents oscillations and integrator windup for unobtainable positions)
• Fix delay in the straight line loop in the movement loop to be consistent (ensures that the controllers are getting steps of equal length in each cycle)
• Fix a few other obscure design issues with the PID controller

The net result of which is that firmware version 0.92 makes the machine faster, smoother, and more accurate. Great work @krkeegan!!!!!

Maslow Firmware Version 0.91

Since last week @krkeegan has been doing some amazing work (with some REALLY exciting stuff in the pipeline fo next week). His changes this week mostly relate to improving the PID code which controls how the machine moves, as well as some general nice tidying up like fixing the compiler warnings we were seeing and cleaning up the code.

Merged #313 Indent Comments to Match Surrounding Code
Merged #312 Fix Compiler Warnings that Appear with Default Settings
Merged #311 Allow Weighting of Proportional on Error/Measurements
Merged #309 Don't Run PID Calculation if Motors are Detached/Unpowered
Merged #308 Upgrade PID Library to v1.2.1
Merged #307 Add B Functions for Testing PID Settings

Maslow Firmware Version 0.90

This week's firmware has mostly minor changes and general upkeep.

v0.90 turns off the verbose debug feature which was resulting in a lot of information being displayed to Ground Control, and replaces a constant in the way the motor RPM is calculated which could result in poor PID performance for those building Maslow's with custom encoders.

Have a great week everyone!

Maslow Firmware Version 0.89

This week's firmware includes a lot of fantastic changes from @wrh3c mostly related to preventing buffer overflow issues and making sure gcode lines are read correctly

Maslow Firmware Version 0.88

Version 0.88 of the Maslow firmware ensures that proper settings have been received from Ground Control before trying to determine the machine's position reducing the chance of seeing the dreaded "cannot find position" popup.

Have a great week everyone!

Maslow Firmware Version 0.87

Firmware version 0.87 makes sure that some values needed for the new triangular kinematics system are recomputed when the machine's dimensions are changed.

Maslow Firmware Version 0.86

No changes to the firmware this week!

Version number incremented for consistency with Ground Control

Maslow Firmware Version 0.85

This week's firmware fixes an issue with the machine being unable to load it's position after being disconnected and reconnected to Ground Control which was resulting in a "Please calibrate chain lengths" message.

The issue was that if the machine tried to load it's position from memory before it had been told the specs for the motors it would load an incorrect position, then save incorrect chain lengths to memory. The next time the position was loaded from memory it would be wrong and the machine would try to compute a new position from the incorrect chain lengths and fail.

Firmware version 0.85 fixes this when pared with Ground Control 0.85