Skip to content

fix(firmware): guard invalid servo position reads #86

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Forairaaaaa merged 1 commit into from
Jun 8, 2026
+32 −2
Merged

fix(firmware): guard invalid servo position reads #86

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
34 changes: 32 additions & 2 deletions firmware/main/hal/hal_servo.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -83,7 +83,17 @@ class ScsServo : public Servo {
int getCurrentAngle() override
{
int current_pos = _scs_bus.ReadPos(_config.id);
int angle = (current_pos - _zero_pos) * 5 * 10 / 16;
if (!is_raw_pos_valid(current_pos)) {
int fallback_angle = uitk::clamp(Servo::getCurrentAngle(), getAngleLimit().x, getAngleLimit().y);
mclog::tagWarn(_tag,
"id: {} ignore invalid current pos: {}, fallback angle: {}",
_config.id,
current_pos,
fallback_angle);
return fallback_angle;
}

int angle = raw_pos_to_angle(current_pos);
angle = uitk::clamp(angle, getAngleLimit().x, getAngleLimit().y);
// mclog::tagInfo(_tag, "id: {} current pos: {} angle: {}", _id, current_pos, angle);
return angle;
Expand Down Expand Up @@ -112,7 +122,17 @@ class ScsServo : public Servo {

void setCurrentAngleAsZero() override
{
_zero_pos = _scs_bus.ReadPos(_config.id);
int current_pos = _scs_bus.ReadPos(_config.id);
if (!is_raw_pos_valid(current_pos)) {
mclog::tagWarn(_tag,
"id: {} ignore invalid zero calibration pos: {}, keep zero pos: {}",
_config.id,
current_pos,
_zero_pos);
return;
}

_zero_pos = current_pos;

Settings settings(_config.settingNs, true);
settings.SetInt(_config.settingZeroPositionKey, _zero_pos);
Expand Down Expand Up @@ -151,6 +171,16 @@ class ScsServo : public Servo {
int _zero_pos = 0;
Mode _current_mode = Mode::Position;

bool is_raw_pos_valid(int raw_pos) const
{
return raw_pos >= _config.rawPosLimit.x && raw_pos <= _config.rawPosLimit.y;
}

int raw_pos_to_angle(int raw_pos) const
{
return (raw_pos - _zero_pos) * 5 * 10 / 16;
}

void check_mode(Mode targetMode)
{
if (targetMode == _current_mode) {
Expand Down