# Voltage Reading Not Working – Cube Orange+ + CUAV CAN PMU (works only with old PWM config) **URL:** \ **Category:** Cube Autopilot\ **Created:** [13 October 2025 20:32 UTC](https://discuss.cubepilot.org/t/voltage-reading-not-working-cube-orange-cuav-can-pmu-works-only-with-old-pwm-config/17055 "2025-10-13T20:32:44Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Dragonfly\_Lab](https://discuss.cubepilot.org/user_avatar/discuss.cubepilot.org/dragonfly_lab/32/9244_2.png) [@Dragonfly\_Lab](https://discuss.cubepilot.org/u/Dragonfly_Lab)\ **Post date:** [13 October 2025 20:32 UTC](https://discuss.cubepilot.org/t/voltage-reading-not-working-cube-orange-cuav-can-pmu-works-only-with-old-pwm-config/17055/1 "2025-10-13T20:32:45Z")
Hello guys, I’m really losing my mind over this one and could use some help figuring it out. I’m using a **Cube Orange+** flight controller with a **CUAV CAN Power Module (PMU)**. * * * ### **What’s happening** - I followed the official setup instructions, but got **no voltage reading at all** (shows **0.0 V** in Mission Planner). - Then, I got a **working configuration file** from a friend — and with that, voltage readings appeared correctly. - The problem is, that configuration uses **PWM outputs** for the ESCs, while I need **DSHOT**. - I switched everything over to DSHOT, and it worked _briefly_, but now — even though nothing was changed — the **voltage reading stopped working again**. - The **current reading still works fine**. * * * ### **Setup details** - **Flight controller:** Cube Orange+ - **Power module:** CUAV CAN PMU - **Firmware tested:** ArduPilot (tested with **4.5.6** and **4.6.2** ) - **Connection:** Mission Planner connected via **USB** - **Power source:** regulated **bench power supply** * * * ### **Files** I’ve attached both configuration files: - `DshotConfigurationNoVoltage.` - `PWMConfWithVoltReading.param` → voltage reads **correctly** * * * ### **Additional info** - The **CUAV PMU shows up correctly in the CAN device list** , so it’s definitely being detected. - I confirmed it’s **powered properly** , and the CAN status LED behaves normally. - I double-checked the `BATT_MONITOR` parameter and CAN node assignment. - The only difference I can see between the working and non-working configs is the **output protocol (PWM vs DSHOT)**. * * * ### **Question** Does anyone know why switching to **DSHOT** would cause the **voltage reading** (from the CUAV CAN PMU) to stop working — while the **current reading still works fine**? Could this be related to CAN bus initialization timing, `BATT_MONITOR` configuration, or an interaction with `SERVO_DSHOT_ESC` / `SERVO_BLH_AUTO`? Any help or insight would be really appreciated — I’ve been stuck on this for days. Thanks! **Misha** ---
**Author:** ![xfacta](https://discuss.cubepilot.org/letter_avatar_proxy/v4/letter/x/5f8ce5/32.png) [@xfacta](https://discuss.cubepilot.org/u/xfacta)\ **Post date:** [13 October 2025 21:37 UTC](https://discuss.cubepilot.org/t/voltage-reading-not-working-cube-orange-cuav-can-pmu-works-only-with-old-pwm-config/17055/2 "2025-10-13T21:37:42Z")
Try setting `BRD_BOOT_DELAY,3000` whenever using CAN devices. It’s not strictly necessary but cant hurt, and it’s OK to leave in place even when not using CAN. In the DSHOT param file you’ve got **NO** servo functions set. The Main outs (Servo1 - 8) dont do DSHOT unless you set `BRD_IO_DSHOT,1` (which you have) but I think it’s limited to DSHOT300 and I’m unclear if it even works with Plane, maybe only tested with Copter. You could move your DSHOT outputs to Servo9 upwards and test with `BRD_IO_DSHOT,0` to see if that makes a difference. ---
**Author:** ![Dragonfly\_Lab](https://discuss.cubepilot.org/user_avatar/discuss.cubepilot.org/dragonfly_lab/32/9244_2.png) [@Dragonfly\_Lab](https://discuss.cubepilot.org/u/Dragonfly_Lab)\ **Post date:** [16 October 2025 08:53 UTC](https://discuss.cubepilot.org/t/voltage-reading-not-working-cube-orange-cuav-can-pmu-works-only-with-old-pwm-config/17055/3 "2025-10-16T08:53:18Z")
Thank you very much for the reply. I have no servos because its a setup for a motor and prop testbench, so i need just a single Dshot output, and this part works just fine. ill try the Delay ---
**Author:** ![xfacta](https://discuss.cubepilot.org/letter_avatar_proxy/v4/letter/x/5f8ce5/32.png) [@xfacta](https://discuss.cubepilot.org/u/xfacta)\ **Post date:** [17 October 2025 07:11 UTC](https://discuss.cubepilot.org/t/voltage-reading-not-working-cube-orange-cuav-can-pmu-works-only-with-old-pwm-config/17055/4 "2025-10-17T07:11:08Z")
Yeah, by “servo” I mean anything that connects to the Main or Aux outputs like an ESC or servo.