SO-ARM101 Wireless Teleoperation Troubleshooting Guide (NanoCam Version)

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This page collects common troubleshooting for the ESP32-NanoCam version of the SO-ARM101 wireless teleoperation. For the complete workflow, see SO-ARM101 Wireless Teleoperation (ESP32-NanoCam Version).

General Troubleshooting Quick Reference

Symptom	Check
Cannot connect for flashing	Manually enter download mode (BOOT + reset); add upload_port in platformio.ini
No serial output after flashing	Check the USB cable and the CH340 driver; on Windows check the COM port in Device Manager
Stuck at Waiting for micro-ROS Agent...	Check AGENT_IP / UDP 8888 / client isolation
Servo bus not responding (servo_mask≠0x3f)	Make sure it is wired to P2-7/P2-8 through the servo driver board UART; follower arm on 12V 5A external power
Microphone level stuck at 0	Check the audio: ES8311 ready log; I2C 41/42 pull-ups; blow at the microphone to verify
Speaker silent	Check the speaker connection; ES8311 volume register R_DAC32 (set to max 0xFF in the current firmware)
WiFi frequently drops	Check the antenna and distance; the RGB turning red indicates WiFi loss, with auto-reboot after 10s

Flashing and Serial Problems

• Cannot connect for flashing: hold the BOOT button (GPIO0) → plug in USB (or press reset) → release BOOT, then immediately re-run upload. On Windows, if the serial port is not detected automatically, add a line upload_port = COM3 under [env:nano_cam] in platformio.ini (replace it with the CH340's actual COM number from Device Manager).
• No serial output after flashing: the NanoCam's USB is CH340K → UART0, with the device name /dev/ttyUSB0 under Linux; if it is not recognized when plugged in, check the USB cable and the CH340 driver (bundled in the kernel).
• Servo bus not responding (servo_mask≠0x3f): make sure the servo bus is wired to P2-7/P2-8 (GPIO19/20) through the servo driver board UART, not to UART0's 43/44; the follower arm must use 12V 5A external power (USB cannot drive 6 servos).
• Servo bus confused with the debug serial: the debug serial is USB-C (CH340K → UART0), completely independent of the servo bus, and the two can be used at the same time.

Build and Toolchain Problems

• First pio run downloads slowly / appears stuck (the first run downloads, in order, the espressif32 platform, the toolchain-xtensa-esp32s3 toolchain (~100 MB) and the Arduino framework (~200 MB)): PlatformIO's time-remaining estimate is inaccurate — it often appears stuck for a while and then suddenly jumps to done; give it 5 minutes and watch whether the percentage advances; you can turn on a proxy/VPN (uses the system proxy);
• Download the toolchain manually: get https://dl.espressif.com/dl/xtensa-esp32s3-elf-gcc8_4_0-esp-2021r2-patch5-win32.zip in a browser (the Linux equivalent is -linux-amd64.tar.gz), unzip it, rename the directory to toolchain-xtensa-esp32s3, place it in C:\Users\<username>\.platformio\packages\, and re-run pio run; a Ctrl+C interruption midway does not damage the environment, and re-running resumes the download;
• The pio command is not found in Git Bash on Windows: use a PowerShell/CMD terminal instead, or add C:\Users\<username>\.platformio\penv\Scripts to PATH.

Camera-Specific Troubleshooting

Symptom	Root cause	Fix
i2c driver install error + camera probe failed	I2C conflict: ES8311 occupies GPIO41/42 via Wire1, so the camera SCCB's attempt to install the I2C driver is rejected	Add Wire1.end() at the end of init() in audio_es8311.cpp to release the I2C for the camera
JPEG format is not supported on this sensor (0x106)	The GC2145 has no hardware JPEG encoder (only the OV2640/OV5640 do)	Switch capture to PIXFORMAT_RGB565; /stream and /jpg use frame2jpg to software-encode into JPEG
/jpg, /stream no response, browser spins forever	httpd stack overflow: the default 8KB stack cannot fit frame2jpg software encoding	Set config.stack_size = 16384 in start_server()
/stream opens but shows a black screen	Missing multipart boundary: no STREAM_BOUNDARY is sent between frames, so the browser cannot parse it	Send STREAM_BOUNDARY before each frame
curl to /jpg returns HTTP:000, but the browser shows the image	esp_http_server is single-tasking: while /stream occupies the httpd task, /jpg cannot get a slot; or the curl timeout is too short	Close /stream and test /jpg separately; verify in a browser instead of curl
Camera initializes successfully but is all black / no frames	Usually hardware: AVDD/DOVDD power, PWDN level, ribbon contact	First test a snapshot with /jpg in a browser (an image means the link works); check the camera 2.8V supply and the ribbon cable
Corruption on the bottom ~2/3 of the VGA image	DVP data rate too high: VGA RGB565 exceeds this board's DVP sampling timing margin (reproduced with 24/20/16MHz × single/double buffering); QVGA is fine	Use QVGA 320×240 in the production configuration (good enough for FPV), or switch to a more stable XCLK / change the DVP hardware routing

Remark: the first four items in the table are already fixed in the bundled firmware — just flash the latest firmware, no manual code changes needed.

Note: esp_http_server is single-tasking, so /stream and /jpg cannot be accessed at the same time — while /stream is open, /jpg hangs indefinitely. Close the stream page before grabbing a single frame.

Audio-Specific Troubleshooting

Symptom	Root cause	Fix
Speaker completely silent + microphone level ≈ 0 (e.g. 0.0009)	MCLK not output: the legacy I2S driver does not generate MCLK on the ESP32-S3, so the ES8311 internal DAC/ADC has no clock	Use LEDC to generate a 6.15MHz MCLK on GPIO39 (start_ledc_mclk() in audio_es8311.cpp)
Tones too quiet (only audible with an ear against it)	Low digital amplitude + low ES8311 master volume	play_tone amplitude 12000→30000, R_DAC32 0x30→0xFF (~+29dB)
Only the startup "beep beep" after power-on, no other tones	Normal behavior: the ready/unlock tones are event-driven and require running the teleoperation	Startup tone = plays at power-on; ready tone = Agent communication established; unlock tone = control command received

Remark: the first two items are already fixed in the bundled firmware; the third is normal behavior and needs no action.

Microphone, Speaker, and RGB Hardware Checks

• Microphone level stays at 0: check the audio: ES8311 ready log; confirm MCLK is output (GPIO39 should show ~1.65V, generated by LEDC); I2C bus 41/42 pull-ups (10K already on the board); blow at the microphone and see whether /follower_audio/level fluctuates.
• Speaker silent: confirm the NS4150B speaker is connected to the speaker connector; confirm GPIO39 MCLK is output (LEDC, start_ledc_mclk()); volume register R_DAC32 (currently 0xFF); if the ES8311 fails to initialize, the log prints the failure reason.
• RGB LED does not light: the WS2812 data pin is GPIO18; check the firmware boot log for an RMT initialization error before camera_stream appears (generally will not happen).

Network and micro-ROS Problems

• Stuck at Waiting for micro-ROS Agent...: check in order whether AGENT_IP is set to the Ubuntu PC's LAN IP, whether UDP 8888 is allowed, and whether the router/hotspot has client isolation enabled (it must be off). The NanoCam's antenna is the U.FL antenna on the module; if the RSSI is poor, first check the antenna and its placement, and it is recommended to run real distance tests at 5/10/20/30 m.
• WiFi frequently drops: check the antenna and distance; the RGB turning red indicates WiFi loss, and the firmware auto-reboots after a 10s timeout.
• When nothing connects, verify the environment first: the NanoCam and the Ubuntu PC must be on the same 2.4GHz LAN (a phone hotspot will do); if you changed networks, remember to update AGENT_IP and the WiFi configuration accordingly (see the "Configure WiFi" section of the wireless teleoperation tutorial).

Related Products

SO-ARM101 Developer Kit→esp32-s3-wifi-module→