# Starling 2 / VOXL2 M0129 ESC not detected during voxl-esc scan or firmware upgrade

Source: https://forum.modalai.com/topic/5125/starling-2-voxl2-m0129-esc-not-detected-during-voxl-esc-scan-or-firmware-upgrade
Category: VOXL SDK and Software (https://forum.modalai.com/category/47/voxl-sdk-and-software)
Tags: voxl-sdk
Posted: 2026-03-23 16:37:19 UTC by syamala kotireddy
Replies: 0 · Views: 813

## syamala kotireddy · 2026-03-23 16:37:19 UTC

Hi ModalAI team,

I am working on a Starling 2 / VOXL2 setup and I am stuck with an ESC communication / firmware issue. I would appreciate your guidance on whether this looks like a software mismatch, a known M0129 compatibility issue, or a hardware-side comms problem.

Hardware / platform:
- VOXL2 (M0054)
- Starling 2 platform
- ESC board label: M0129
- SKU shown on device:
  MRB-D0014-4-V1-C27-T9-M22-X0

Current software versions:
- system-image: 1.8.06-M0054-14.1a-perf
- voxl-suite: 1.6.3
- voxl-esc package manually upgraded from 1.5.7 to 1.6.1

What I did:
1. Reflashed the board
2. Restored / checked calibration as needed
3. Verified Wi-Fi and internet access
4. Confirmed newer voxl-esc was available in sdk-1.6 and manually installed:
   dpkg -i /data/voxl-esc_1.6.1_arm64.deb
5. Checked available firmware files under:
   /usr/share/modalai/voxl-esc-tools/firmware/

Firmware files present for M0129:
- modalai_esc_firmware_m0129_3_v39_25_a58f5f6f.bin
- modalai_esc_firmware_m0129_6_v39_25_a58f5f6f.bin

Note:
- My physical ESC only says M0129
- I do not see a suffix like M0129-3 or M0129-6 printed on the board
- I also do not see an m0129_1 firmware file in the installed firmware folder

Main issue:
- voxl-esc scan does not reliably detect any ESCs
- voxl-esc upgrade_firmware sometimes previously said “successfully pinged ESCs” but then failed with:
  [ERROR] Unknown board detected:
- After deeper testing, the underlying Python tools also fail to detect the ESC consistently

Direct tool results:

1) voxl-esc-scan.py
- No ESCs detected at all baud rates
- Sometimes reports:
  ERROR: voxl_uart_read_bytes: Bus '12' is not initialized

2) voxl-esc-board-detect.py
- Ends with:
  ERROR: No ESC(s) detected, exiting.

3) Debug scan:
Command used:
python3 voxl-esc-scan.py --enable-debug True --force-scan-all-baud-rates True

Observed behavior:
- UART TX packets are clearly being sent
- No valid UART RX from ESC
- In one case RX was all zeros after:
  ERROR: voxl_uart_read_bytes: Bus '12' is not initialized
- Every scan ends with:
  WARNING: No ESC(s) detected
  ERROR: not all ESCs found

Relevant logs:
- dmesg shows SLPI restart events after reset commands, for example:
  Fatal error on slpi!
  ... Got kill command from apps processor.
- /dev shows SLPI subsystem nodes, but the scan path still fails to get a valid ESC reply

Important observations:
- The VOXL side appears to be transmitting on the ESC link
- The ESC side does not appear to respond
- This now looks more like a low-level comms / wiring / power / bootloader issue than just a wrapper-script issue

Questions:
1. Is system-image 1.8.06 with voxl-suite 1.6.3 a supported combination for Starling 2 + M0129 ESC?
2. For an ESC labeled only “M0129”, which firmware should be used:
   - m0129_3
   - m0129_6
   - or is there another variant / package expected?
3. Is the missing response from the ESC more indicative of:
   - incorrect harness / connector / pinout
   - ESC not powered correctly
   - damaged ESC MCU
   - wrong firmware / bootloader state
4. Is there a recommended low-level recovery path for M0129 when voxl-esc-scan.py cannot detect any ESCs?
5. Are there any additional commands you want me to run to verify the ESC UART / SLPI bridge path on this platform?

Example command outputs:

system image / suite:
- system-image: 1.8.06-M0054-14.1a-perf
- voxl-suite: 1.6.3

voxl-esc version after manual install:
- 1.6.1

Direct scan result:
- WARNING: No ESC(s) detected
- ERROR: not all ESCs found

Direct board detect result:
- ERROR: No ESC(s) detected, exiting.

Any help would be greatly appreciated. I can also provide full logs or photos of the ESC board/harness if needed.

Thank you.