diff --git a/Firmware/planner.cpp b/Firmware/planner.cpp index 197b3d9f..57d7b89b 100644 --- a/Firmware/planner.cpp +++ b/Firmware/planner.cpp @@ -1137,17 +1137,24 @@ Having the real displacement of the head, we can calculate the total movement le // still need to replicate the *exact* same step grouping policy (see below) float advance_speed = (extruder_advance_K * e_D_ratio * block->acceleration * cs.axis_steps_per_unit[E_AXIS]); if (advance_speed > MAX_STEP_FREQUENCY) advance_speed = MAX_STEP_FREQUENCY; - block->advance_rate = (F_CPU / 8.0) / advance_speed; - if (block->advance_rate > 20000) { - block->advance_rate = (block->advance_rate >> 2)&0x3fff; + float advance_rate = (F_CPU / 8.0) / advance_speed; + if (advance_speed > 20000) { + block->advance_rate = advance_rate * 4; block->advance_step_loops = 4; } - else if (block->advance_rate > 10000) { - block->advance_rate = (block->advance_rate >> 1)&0x7fff; + else if (advance_speed > 10000) { + block->advance_rate = advance_rate * 2; block->advance_step_loops = 2; } else + { + // never overflow the internal accumulator with very low rates + if (advance_rate < UINT16_MAX) + block->advance_rate = advance_rate; + else + block->advance_rate = UINT16_MAX; block->advance_step_loops = 1; + } #ifdef LA_DEBUG if (block->advance_step_loops > 2)