IN100 : “Failed to write eFuse, maybe it is VDDQQ power issue!”

Other
1

Hi InPlay Support Team,

can you please connect me with any technical expert to help me to resolve this problem?

We are evaluating the IN100 NanoBeacon for a beacon application involving an I2C temperature sensor (TMP110), with the intent to move to high-volume production if the evaluation is successful.

─── Issue Summary ───────────────────────────────────

During OTP burn, the NanoBeacon Config Tool fails at 8% progress with the following error:

“Failed to write eFuse, maybe it is VDDQQ power issue!”

RAM mode works correctly — all advertising data functioning as expected.hence i2c test not support in RAM mode to test I2c we burn. The failure occurs exclusively during the Burn/Program step.

─── Hardware Setup ──────────────────────────────────
Programmer : PL2303 USB-to-UART (TTL) module

Connections:
PL2303 3.3V ── NanoBeacon VCC
PL2303 GND ── NanoBeacon GND
PL2303 TX ── NanoBeacon RX
PL2303 RX ── NanoBeacon TX

using dev Board form SmartElex hence quick available at our location.

Board under test : SparkFun NanoBeacon Board - IN100

─── Power Supply Attempts ───────────────────────────
We have attempted burn with two separate power sources with two board — both result in the same error at 8%:

Attempt 1 : CR1225 coin cell (3V) via onboard battery holder
Attempt 2 : external power by nordic PPK2 (external regulated supply)

In both cases, TX/RX communication is stable and RAM mode executes without any issue.

─── Software ────────────────────────────────────────
Config Tool version : NanoBeaconConfigToolMpTool_V3.3.4B
OS : Windows

─── Attachments ─────────────────────────────────────

  1. config file

config.txt (5.5 KB)

2. GUI error screenshot

Screenshot 2026-03-31 172308
Screenshot 2026-03-31 1723081349×655 18.1 KB

─── Questions ───────────────────────────────────────
1. What is the minimum VCC current capability required specifically
during eFuse/OTP programming? Is there a VDDQQ specification
separate from the normal operating VCC?

2 . Are there any known issues with OTP burn on the SmartElex
NanoBeacon board variant at this tool version?

3. any pre-process before burn with e-fuse?

Any guidance or troubleshooting steps would be greatly appreciated. as we have one more fresh board left to try any. We are keen to resolve this quickly as this evaluation directly influences
our volume procurement decision.

(NOTE: gui downloaded from INplay website(NanoBeaconConfigToolMpTool_V3.2.29) and then updated by prompt on gui launch to ask for update to V3.3.4B.

Best regards,
Jay.
shipmentia(WaveInnova)

2
  1. 3.3v for VCC, though note VCC isn’t the problem here…it has a separate spec from VDDQ; the datasheet says VDDQ requires 3.3V with high transient current capability (20–50mA peak)
  2. Not specifically, but I’m suspicious that it is the issue (not providing the power the IN100 wants to burn the E-fuse)
  3. No, but like you mentioned I2C can’t be validated in RAM mode…I’d just make sure the sketch works as expected using a separate MCU and bingo (verify the i2c address for your sensor, etc)

Because you have a volume procurement on the line, I’d recommend simply grabbing the InPlay programmer board Getting Started with the InPlay NanoBeacon™ IN100 — InPlay (shown on the right if you scroll down slightly here) and try again using that instead?

FWIW I have previously burned one successfully using our Serial Basic, I’d presume it can supply adequate transient power during the burn (it’s also what is used in our hookup guide!) :slight_smile:

3

we have SparkFun NanoBeacon Board - IN100 board v1.1 is there any known issue with this?

we used diffeent kind of three power supply with fresh board., but facing same isuue.

4

It is not a previously known issue; we’ve only tested with the mentioned serial basic :-/