Nero Firmware Reference

August 26, 2026 · View on GitHub

Supplement to nero_api.md. Full version matrices and behavioral details. The main API manual keeps a short firmware section.

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Version Evolution (newest first)

Read top to bottom: each row is what changed vs the previous SDK driver.

SDK driver	Constant	Arm firmware	Changes vs previous driver
`v121`	`NeroFW.V121`	≥ 1.21	Fixed: `move_mit` and `move_cpv_vel` keep the requested velocity sign on every joint. Inherits `v120`.
`v120`	`NeroFW.V120`	1.20	Fixed: `get_motor_states` returns real `velocity` (no zeroing). Fixed: `get_cpv_vel` without joint velocity sign flip. Inherits `v112` (CPV, IK, leader/follower, etc.). `move_mit` / `move_cpv_vel` still flip velocity sign on joints 1–7 except joint 6.
`v112`	`NeroFW.V112`	1.12	New: `get_ik_joint_angles`; CPV (`0x181`–`0x187`); `set_motion_mode('cpv')`. Changed: `get_leader_joint_angles` → `0x155`–`0x170`. Changed: leader/follower only (Piper-aligned); default follower; CAN push at power-up; `set_normal_mode` removed (SDK no-op). Inherits `v111`.
`v111`	`NeroFW.V111`	1.11	New: `calibrate_joint`. Changed: `move_mit` 12-bit `t_ff` (±16 N·m all joints); MIT frame without CRC; motion mode encoding; `move_p` / `get_flange_pose` without 1.10 pose workaround; `get_motor_states` only forces `velocity = 0` (no `current` flip).
`default`	`NeroFW.DEFAULT`	≤ 1.10	Baseline: 8-bit `t_ff`; per-joint MIT torque ranges; 1.10 pose workaround on `move_p` / `get_flange_pose`; `get_motor_states` forces `velocity = 0` and negates `current`; leader feedback on `0x501`–`0x507`. No `calibrate_joint`, no CPV public APIs.

How to Choose (quick lookup)

Your firmware (from `get_firmware()`)	`firmeware_version`	Constant
1.21 or later	`"v121"`	`NeroFW.V121`
1.20	`"v120"`	`NeroFW.V120`
1.12	`"v112"`	`NeroFW.V112`
1.11	`"v111"`	`NeroFW.V111`
1.10 or earlier	`"default"` (or omit)	`NeroFW.DEFAULT`

APIs with Firmware Requirements

All other public APIs in nero_api.md are available on every supported driver unless noted in their section.

API / group	Minimum SDK driver	Notes
`get_ik_joint_angles`	`NeroFW.V112`	Firmware ≥ 1.12; feedback after `move_p` / `move_l` / `move_c`
`calibrate_joint`	`NeroFW.V111`	Not on `DEFAULT`
CPV: `move_cpv_`, `get_cpv_`, `set_cpv_*`	`NeroFW.V112`	Joints 1–7 only; on `V120` inherits `V112`
`set_motion_mode('cpv')`	`NeroFW.V112`	`OPTIONS.MOTION_MODE.CPV` on `V112` / `V120`; not on `DEFAULT` / `V111`
`move_mit`	All (behavior differs)	See MIT parameters by version
`set_normal_mode`	All (`V112` differs)	See nero_api.md — `set_normal_mode()`

MIT (`move_mit`) Parameters by Version

Driver	Joints	`t_ff` input range (N·m)	`t_ff` bits	Other
`DEFAULT`	1–7	1–2: ±24; 3–4: ±16; 5–7: ±8	8	Per-joint scaling before encode
`V111`	1–7	All: ±16	12	`v_des` sign flip except joint 6 (firmware workaround)
`V112`	1–7	Same as `V111`	12	Inherits `v111` `move_mit`
`V120`	1–7	Same as `V112`	12	Inherits `v112` `move_mit` (`v_des` sign flip except joint 6; not fixed in 1.20)
`V121`	1–7	Same as `V120`	12	No `v_des` sign flip

API Availability Matrix (full)

Legend: ✅ supported · — not in driver · ⚠️ supported with version-specific behavior.

API / capability	`DEFAULT` (≤ 1.10)	`V111` (1.11)	`V112` (≥ 1.12)
Connect / disconnect, `enable` / `disable`, `reset`	✅	✅	✅
`move_j` / `move_js`	✅	✅	✅
`move_p` / `move_l` / `move_c`	✅	✅	✅
`get_joint_angles`, `get_driver_states`, limits / crash APIs, etc.	✅	✅	✅
`get_ik_joint_angles`	—	—	✅
`move_mit`	✅	✅	✅
`calibrate_joint`	—	✅	✅
CPV (`move_cpv_`, `get/set_cpv_`)	—	—	✅
`get_leader_joint_angles`	✅	✅	✅
`set_leader_mode` / `set_follower_mode`	✅	✅	✅
`set_normal_mode`	✅	✅	⚠️

Version-Specific Behavior (full)

Topic	`DEFAULT` (≤ 1.10)	`V111` (1.11)	`V112` (1.12)	`V120` (1.20)	`V121` (≥ 1.21)
`move_p` / `get_flange_pose`	1.10 pose workaround (send + receive)	No workaround	Inherits `V111`	Inherits `V112`	Inherits `V120`
`get_motor_states`	`velocity = 0`; `current` negated	`velocity = 0` only	Inherits `V111`	Real `velocity`; no workarounds	Inherits `V120`
`move_mit` velocity	Firmware-specific	Sign flip for joints ≠ 6	Inherits `V111`	Inherits `V112`	No sign flip
`move_cpv_vel` velocity	—	—	Sign flip for joints ≠ 6	Inherits `V112`	No sign flip
`get_cpv_vel`	—	—	Sign flip for joints ≠ 6	No sign flip	Inherits `V120`
`get_leader_joint_angles` CAN	`0x501`–`0x507` per joint	Same as `DEFAULT`	`0x155` / `0x156` / `0x157` + `0x170`	Inherits `V112`	Inherits `V120`
Leader–follower / CAN feedback	normal + leader + follower; CAN push via `set_normal_mode` when enabled	Same as `DEFAULT`	leader + follower only (Piper-aligned); default follower; CAN push at power-up; `set_normal_mode` no-op	Inherits `V112`	Inherits `V120`
CPV	Not implemented	Not implemented	Full stack; `0x181`–`0x187`	Inherits `V112`	Inherits `V120`

Per-Version Quick Reference

Firmware ≥ 1.21 → use `NeroFW.V121`

Inherits all V120 APIs and feedback fixes.
move_mit and move_cpv_vel keep the requested velocity sign on every joint.

Firmware 1.20 → use `NeroFW.V120`

Inherits all V112 APIs (IK, CPV, leader/follower).
get_motor_states returns real joint velocity.
get_cpv_vel without SDK sign correction.
move_mit / move_cpv_vel still flip velocity sign on joints 1–7 except joint 6 (firmware not fixed in 1.20).

Firmware 1.12 → use `NeroFW.V112`

get_ik_joint_angles after move_p / move_l / move_c (CAN 0x2AA–0x2AD).
Use CPV and set_motion_mode('cpv').
Leader angles from 0x155 / 0x156 / 0x157 / 0x170.
Leader/follower only; CAN push at power-up (see API manual table).

Firmware 1.11 → use `NeroFW.V111`

calibrate_joint available.
12-bit MIT; fixed flange pose (no 1.10 workaround).
No CPV APIs.

Firmware ≤ 1.10 → use `NeroFW.DEFAULT`

8-bit MIT; pose workaround on Cartesian APIs.
No calibrate_joint, no CPV.

Nero 固件参考

nero_api.md 的补充文档：完整版本矩阵与行为差异。主手册仅保留简短固件说明。

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版本演进（从新到旧）

自上而下阅读：每行表示相对上一档 SDK 驱动的变化。

SDK 驱动	常量	机械臂固件	相对上一版的变化
`v121`	`NeroFW.V121`	≥ 1.21	修复： `move_mit` 和 `move_cpv_vel` 对所有关节都保持调用者传入的速度符号。继承 `v120`。
`v120`	`NeroFW.V120`	1.20	修复： `get_motor_states` 返回真实 `velocity`（不再置 0）。修复： `get_cpv_vel` 不再做关节速度符号翻转。继承 `v112`（CPV、IK、主从等）。`move_mit` / `move_cpv_vel` 仍对 1–7 轴中除第 6 轴外做速度符号 workaround。
`v112`	`NeroFW.V112`	1.12	新增： `get_ik_joint_angles`；CPV（`0x181`–`0x187`）；`set_motion_mode('cpv')`。变更： `get_leader_joint_angles` → `0x155`–`0x170`。变更：仅主从模式（与 Piper 一致）；默认从臂；上电 CAN 推送；取消 `set_normal_mode`（SDK no-op）。继承 `v111`。
`v111`	`NeroFW.V111`	1.11	新增： `calibrate_joint`。变更： `move_mit` 12-bit `t_ff`（全关节 ±16 N·m）；MIT 帧无 CRC；运动模式编码变更；`move_p` / `get_flange_pose` 无 1.10 位姿 workaround；`get_motor_states` 仅将 `velocity` 置 0（不再对 `current` 取反）。
`default`	`NeroFW.DEFAULT`	≤ 1.10	基线： 8-bit `t_ff`；分关节 MIT 力矩范围；`move_p` / `get_flange_pose` 1.10 位姿 workaround；`get_motor_states` 将 `velocity` 置 0 且 `current` 取反；主臂反馈 `0x501`–`0x507`。无 `calibrate_joint`、无 CPV 公开 API。

如何选择（速查）

固件版本（`get_firmware()`）	`firmeware_version`	常量
1.21 及更新	`"v121"`	`NeroFW.V121`
1.20	`"v120"`	`NeroFW.V120`
1.12	`"v112"`	`NeroFW.V112`
1.11	`"v111"`	`NeroFW.V111`
1.10 及更早	`"default"`（或不填）	`NeroFW.DEFAULT`

有固件要求的 API

nero_api.md 中其余公开 API 在各支持驱动上均可用（除非该 API 小节另有说明）。

API / 分组	最低 SDK 驱动	说明
`get_ik_joint_angles`	`NeroFW.V112`	固件 ≥ 1.12；`move_p` / `move_l` / `move_c` 后有反馈
`calibrate_joint`	`NeroFW.V111`	`DEFAULT` 无
CPV：`move_cpv_`、`get_cpv_`、`set_cpv_*`	`NeroFW.V112`	仅 1–7 轴；`V120` 继承 `V112`
`set_motion_mode('cpv')`	`NeroFW.V112`	`V112` / `V120` 的 `OPTIONS.MOTION_MODE` 含 `cpv`；`DEFAULT` / `V111` 不含
`move_mit`	均有（行为不同）	见 MIT 分版本参数
`set_normal_mode`	均有（`V112` 不同）	见 nero_api.md — `set_normal_mode()`

MIT（`move_mit`）分版本参数

驱动	关节	`t_ff` 输入范围（N·m）	`t_ff` 位数	其它
`DEFAULT`	1–7	1–2：±24；3–4：±16；5–7：±8	8	编码前分关节缩放
`V111`	1–7	全关节 ±16	12	除 6 轴外 `v_des` 取反（固件 workaround）
`V112`	1–7	与 `V111` 相同	12	继承 `v111` `move_mit`
`V120`	1–7	与 `V112` 相同	12	继承 `v112` `move_mit`（除第 6 轴外 `v_des` 取反；1.20 未修复）
`V121`	1–7	与 `V120` 相同	12	`v_des` 不取反

API 支持矩阵（完整）

图例：✅ 支持 · — 驱动未实现 · ⚠️ 支持但行为因版本而异。

API / 能力	`DEFAULT`（≤ 1.10）	`V111`（1.11）	`V112`（≥ 1.12）
连接 / 断开、`enable` / `disable`、`reset`	✅	✅	✅
`move_j` / `move_js`	✅	✅	✅
`move_p` / `move_l` / `move_c`	✅	✅	✅
`get_joint_angles`、`get_driver_states`、限位 / 碰撞等	✅	✅	✅
`get_ik_joint_angles`	—	—	✅
`move_mit`	✅	✅	✅
`calibrate_joint`	—	✅	✅
CPV（`move_cpv_`、`get/set_cpv_`）	—	—	✅
`get_leader_joint_angles`	✅	✅	✅
`set_leader_mode` / `set_follower_mode`	✅	✅	✅
`set_normal_mode`	✅	✅	⚠️

版本差异说明（完整）

主题	`DEFAULT`（≤ 1.10）	`V111`（1.11）	`V112`（1.12）	`V120`（1.20）	`V121`（≥ 1.21）
`move_p` / `get_flange_pose`	1.10 位姿 workaround（收发）	无 workaround	继承 `V111`	继承 `V112`	继承 `V120`
`get_motor_states`	`velocity = 0`；`current` 取反	仅 `velocity = 0`	继承 `V111`	真实 `velocity`；无 workaround	继承 `V120`
`move_mit` 速度	固件特定	关节 ≠ 6 时取反	继承 `V111`	继承 `V112`	不取反
`move_cpv_vel` 速度	—	—	关节 ≠ 6 时取反	继承 `V112`	不取反
`get_cpv_vel`	—	—	关节 ≠ 6 时符号翻转	无符号翻转	继承 `V120`
`get_leader_joint_angles` CAN	`0x501`–`0x507` 逐轴	与 `DEFAULT` 相同	`0x155` / `0x156` / `0x157` + `0x170`	继承 `V112`	继承 `V120`
主从 / CAN 反馈	正常+主从；使能后 `set_normal_mode` 开 CAN 推送	与 `DEFAULT` 相同	仅主从（同 Piper）；默认从臂；上电 CAN 推送；`set_normal_mode` no-op	继承 `V112`	继承 `V120`
CPV	未实现	未实现	完整；`0x181`–`0x187`	继承 `V112`	继承 `V120`

分版本用户速查

固件 ≥ 1.21 → `NeroFW.V121`

继承 V120 全部 API 和反馈修复。
move_mit 和 move_cpv_vel 对所有关节保持调用者传入的速度符号。

固件 1.20 → `NeroFW.V120`

继承 V112 全部 API（IK、CPV、主从）。
get_motor_states 返回真实关节速度。
get_cpv_vel 不再做 SDK 符号修正。
move_mit / move_cpv_vel 仍对 1–7 轴中除第 6 轴外做速度符号 workaround（1.20 固件未修复）。

固件 1.12 → `NeroFW.V112`

get_ik_joint_angles：move_p / move_l / move_c 后可用（CAN 0x2AA–0x2AD）。
使用 CPV 及 set_motion_mode('cpv')。
主臂关节角来自 0x155 / 0x156 / 0x157 / 0x170。
仅主从模式；上电 CAN 推送（见 API 手册表格）。

固件 1.11 → `NeroFW.V111`

可用 calibrate_joint。
12-bit MIT；笛卡尔位姿无 1.10 workaround。
无 CPV API。

固件 ≤ 1.10 → `NeroFW.DEFAULT`

8-bit MIT；笛卡尔 API 带位姿 workaround。
无 calibrate_joint、无 CPV。