Can You Build Efficient Motors Without Rare-Earth Magnets? Gati Drives Thinks So

Submitted by Abhishek on

As I sit down to write this piece, I notice the fan whirring above and, for the first time, it occurs to me that it runs on an induction motor. So does every other fan in my office and my home. These motors have been around for a long time, not because they’re the best options out there, but because they’re cheap and do the job. BLDC motors have gained a bit of popularity, but are pricier and usually come with an import dependency problem.

FNIRSI-1014D Oscilloscope Teardown

Authors
Divya Sambhayanamath, Kumudini Balobal, Mahantesh Hosur, Shivanand G Holi
Guide & Review
Sandeep Patil, CTO at RedNerds

Model Name: FNIRSI-1014D
Abstract :
An oscilloscope that retails at INR 13K basically covers all of the hands-on subjects a 4-year engineering syllabus teaches in theory. The only issue is that none of this is practiced. We barely get past MCUs hands-on.
This oscilloscope though has
1. MCU: GD32E230. Well, the pattern is repeating. Any guesses as to which other MCU family this resembles?
2. FPGA: EF2L45LG144 FPGA for heavy-duty processing.
3. SoC: Allwinner F1C100s CPU + RAM + video + audio in one chip
4. Power supply
Check this teardown to get insights into the build, how it all comes together, tool chain for development and what the ballpark cost at 100K volume.

1. Introduction

A digital storage oscilloscope (DSO) is a critical instrument used in electronics for analyzing electrical signals over time. Modern oscilloscopes integrate high-speed analog front-ends, digital signal processing hardware, and graphical user interfaces to provide accurate waveform visualization and measurement.

The FNIRSI-1014D is a dual-channel digital storage oscilloscope designed for portable measurement and educational use. It features a 100 MHz bandwidth, a 1 GS/s sampling rate, and dual input channels, allowing simultaneous measurement of two signals. The device integrates multiple embedded subsystems, including an FPGA for high-speed signal processing, an ARM-based system controller, and a microcontroller dedicated to user interface management.

This teardown study aims to analyze the internal structure of the FNIRSI-1014D oscilloscope by physically disassembling the device and examining the internal hardware architecture. The report explores the following aspects:

  • Mechanical structure of the oscilloscope
  • PCB layout and internal subsystems
  • Signal processing architecture
  • Display system structure
  • User interface hardware
  • Firmware architecture
  • Estimated component cost

The analysis helps understand how modern oscilloscopes integrate analog electronics, digital processing, and embedded computing systems to perform high-speed signal measurement.

2. External Overview of the Oscilloscope

The FNIRSI-1014D oscilloscope is housed in a plastic enclosure designed for handheld or bench operation. The front panel contains the display, input connectors, and control knobs. The rear panel contains labeling and structural support elements.

The device is designed for ergonomic operation with dedicated controls for waveform scaling, triggering, and signal acquisition.

External Structural Views

The device was inspected from multiple orientations to understand its mechanical design.

  1. Front View – Contains display, knobs, and connectors
  2. Top View—Houses' ventilation and structural support
  3. Bottom View – Contains mounting points and base supports
  4. Back View – Includes product information and identification labels

 

3. Technical Specifications

The FNIRSI-1014D oscilloscope includes several performance parameters that define its signal acquisition capability.

PARAMETERSPECIFICATION
ModelFNIRSI-1014D
Bandwidth100 MHz
Sampling Rate1 GS/s
Number of Channels2
Input Impedance1 MΩ
Rise Time3 ns
Storage Depth240 Kbit
Sensitivity Range50 mV – 500 V
Time Base50 s – 10 ns
Trigger ModesSingle / Normal / Auto

These specifications determine the oscilloscope's ability to capture fast signals while maintaining accurate timing and voltage measurement.

4. PCB Architecture and Internal Hardware Layout

The oscilloscope uses a multi-layer FR-4 printed circuit board integrating analog, digital, and power subsystems on a single board.
The PCB can be divided into five major subsystems:

  1. Input Signal Interface
  2. Analog Front End and Sampling System
  3. FPGA-based Signal Processing Unit
  4. System Control Processor
  5. Power Regulation Network

The board design includes extensive ground planes, copper pours, and via stitching to reduce electromagnetic interference and maintain signal integrity during high-speed operation.

5. Input Processing Architecture

The input processing block is responsible for receiving external signals and preparing them for digital conversion.

The block consists of:

  • BNC input connectors
  • Analog front-end conditioning circuits
  • Relay-based voltage range selection
  • Signal attenuation networks
  • Trigger detection logic

The front panel includes rotary encoders and buttons, which are read by a GD32E303 microcontroller responsible for interpreting user commands.

The decoded commands are then forwarded to the FPGA and system controller.

Flow of Input Processing

  1. The user rotates knobs or presses buttons.
  2. MCU interprets user inputs.
  3. Analog signal enters through BNC connectors.
  4. The analog front-end conditions the signal.
  5. FPGA receives sampled data.
  6. Data is sent to the system processor for display.

This architecture allows the oscilloscope to respond quickly to user commands while maintaining high-speed signal acquisition.

6. FPGA-Based Data Processing

The core signal processing engine of the oscilloscope is the ANLOGIC EF2L45 FPGA.
Field Programmable Gate Arrays are widely used in oscilloscopes because they can process signals in parallel hardware logic, enabling extremely high processing speeds.

The FPGA performs several critical operations:

  • High-speed signal acquisition
  • Trigger detection
  • Timing synchronization
  • Waveform buffering
  • Digital signal processing

Internal FPGA resources include:

  • DSP blocks
  • Block RAM buffers
  • Clock management units
  • High-speed system buses

Data Processing Flow

  1. ADC samples incoming signal
  2. FPGA receives digital samples
  3. Trigger logic detects capture condition
  4. Waveform data stored in memory buffers
  5. Data transferred to system controller

This hardware-level parallel processing enables real-time waveform acquisition.

7. Display and User Interface Processing

The Allwinner F1C100s system-on-chip serves as the main system controller.
This processor performs the following functions:

  • User interface management
  • Waveform rendering
  • Menu system control
  • Storage management
  • System communication

The processor includes several hardware interfaces, such as:

  • SPI
  • UART
  • USB
  • GPIO
  • SDIO

The SoC converts waveform samples received from the FPGA into graphical waveform plots displayed on the LCD screen.

8. LCD Display System Architecture

The oscilloscope uses a 7-inch TFT LCD display with a resolution of 800×480 pixels.
The display is composed of several layered optical structures that allow light modulation to form visible images.

LCD Layer Structure

The display consists of multiple layers arranged from back to front:

  1. LED Backlight
  2. Diffuser Layer
  3. Rear Polarizer
  4. Liquid Crystal Layer
  5. RGB Color Filters
  6. Front Polarizer
  7. Protective Glass Layer

9. LCD Display Working Principle

The TFT LCD operates using the principle of polarized light modulation through liquid crystal molecules.

Display Operation

  1. An LED backlight generates white light.
  2. A diffuser spreads light uniformly.
  3. The rear polarizer aligns light polarization.
  4. Liquid crystal molecules rotate polarization when voltage is applied.
  5. RGB filters create colored pixels.
  6. Front polarizer controls light transmission.
  7. Glass cover protects the display.

This process converts electrical signals into visible graphical waveforms.

10. Front Panel Control System

The oscilloscope includes several user interface controls that allow the user to interact with the measurement system.

Main Controls

Power Button
Activates the device and powers the internal electronics.
USB Host Interface
Used for exporting captured waveform images and measurement data.
Vertical Controls
Adjust voltage scaling (V/div) and channel positioning.
Horizontal Controls
Control time base (s/div) and waveform scrolling.
Trigger Controls
Determine the starting point for waveform capture.
Input Ports
BNC connectors provide electrical signal input.

11. Rotary Encoder Control Mechanism

The control knobs use incremental rotary encoders that generate quadrature pulses when rotated.

Encoder Operation

  1. Encoder rotation generates digital pulses.
  2. MCU reads pulse direction and count.
  3. MCU converts movement into parameter adjustments.
  4. Commands sent to FPGA.
  5. FPGA modifies signal processing parameters

12. Complete System Architecture

The complete oscilloscope system integrates multiple hardware subsystems working together.

Signal Flow

  1. The signal enters through BNC input connector
  2. The analog front-end conditions the signal
  3. ADC samples a signal.
  4. FPGA processes waveform data
  5. ARM SoC renders a waveform.
  6. LCD displays the waveform.

This architecture separates high-speed hardware processing from user interface control, improving overall performance.

13. Firmware Architecture

The oscilloscope uses a multiprocessor firmware architecture.

Microcontroller Firmware (GD32F303)

  • Reads knobs and buttons
  • Controls relay switching
  • Sends control commands to FPGA

FPGA Logic

  • High-speed signal acquisition
  • Trigger detection
  • Waveform buffering

System Processor Software

  • Runs embedded Linux
  • Manages display graphics
  • Handles file storage

14. Cost Analysis of Components

Based on an estimated production volume of 100,000 units, the approximate component cost is:

COMPONENTESTIMATED COST
FPGA₹950
Soc Processer₹270
Microcontroller₹140
Power Management₹135
PCB₹625
External Parts₹550
TFT LCD Display₹1950

Total Estimated Cost: ₹4620 per unit

15. Conclusion

The teardown analysis of the FNIRSI-1014D oscilloscope reveals a well-integrated embedded measurement system combining analog electronics, digital hardware, and embedded software.

The architecture uses three main processing elements:

  • FPGA for high-speed signal processing
  • ARM SoC for display and system control
  • Microcontroller for user interface management

This distributed architecture enables the oscilloscope to achieve high sampling rates while maintaining responsive user interaction.

The multi-layer PCB design, controlled impedance routing, and dedicated power regulation ensure stable operation and accurate signal acquisition. The FNIRSI-1014D demonstrates how modern oscilloscopes integrate multiple computing platforms and specialized hardware to deliver high-performance measurement capabilities at relatively low manufacturing cost.

You may reach out to the RedNerds team for custom product development here: http://www.therednerds.com/

Have any question related to this Article?

How to activate Airtel M2M IoT SimCard with Geolinker ESP32

Airtel M2M IoT SIM Activation – Quick Overview

  1. Log in to Circuit Digest Cloud & open the GeoLinker dashboard
  2. Enter ICCID and mobile number, verify OTP.
  3. Submit KYC documents (within 7 days)
  4. KYC verified by Airtel
  5. Whitelist up to 4 numbers for SMS/Voice

What is an Airtel M2M SIM Card?

An Airtel M2M SIM card is specifically developed for communicating from one machine to another using the cellular networks. The Airtel M2M SIM is designed specifically for IoT and embedded devices that do not require a human operator or user to operate autonomously.

Feature           Airtel M2M SIMRegular SIM
Primary UseIoT devices, GPS trackers, automationPersonal voice and data use
Number RegulationDoT-mandated whitelisting (max 4 numbers)Open communication with all numbers
KYC RequirementMandatory within 7 days of activationRequired at purchase
ManagementRemote via Circuit Digest Cloud platformVia carrier app or store
Included Plan3-month free plan (GeoLinker bundle)Varies by plan

Accessing the Airtel M2M SIM Dashboard on Circuit Digest Cloud

The Airtel SIM Management feature allows you to manage your IoT SIM cards directly from the Circuit Digest Cloud Platform. You can view SIM details, monitor data usage, submit KYC documents, and track device connectivity. To access the Airtel M2M dashboard, log in to your Circuit Digest Cloud Account. Once logged in, you can click on the view button under the GeoLinker section. The Airtel M2M SIM card is a specialised IoT SIM designed for machine-to-machine communication over India's cellular network. This makes it ideal for secure, internet-independent projects such as GPS trackers, remote automation systems, and GSM-based IoT devices. Before you can use the SIM for voice calls, SMS, or data, you need to complete the Airtel M2M SIM activation process through the Circuit Digest Cloud platform.

Circuit Digest Cloud dashboard showing the GeoLinker IoT SIM management section for Airtel M2M SIM card

Step 1 ⇒ How to Activate Your Airtel M2M IoT SIM Card

Once you are in the GeoLinker Dashboard, click on the Airtel IOT SIM, which will redirect you to the Airtel IOT SIM  dashboard. This is where you can see all the activated SIM card details. To activate a SIM card, click on the Activate SIM button in the top right corner.

Airtel IoT SIM dashboard showing total SIM count, active SIMs, and data usage with the Activate SIM button highlighted

In the activation page, enter the ICCID and your mobile number. The ICCID can be found on the SIM package, mentioned as SIM number, or you can get it from the serial output when you insert the SIM into the GL868_ESP32 with factory firmware. Check the Factory firmware section for more details. If you are using the number from the package, avoid the last alphabet; only the numeric number is needed. Click on send OTP to receive the OTP on your entered mobile number.

GeoLinker SIM activation screen showing ICCID entry field, mobile number input, and OTP verification for Airtel M2M SIM card

Once the OTP is verified, you will be redirected to the KYC submission page.

Step 2 ⇒ Completing KYC for Your Airtel M2M SIM Card

Airtel M2M SIM KYC verification screen on Circuit Digest Cloud showing document upload options and selfie capture

IMPORTANT: While you can start using the SIM immediately after OTP verification, you must complete the full KYC process within 7 days to avoid deactivation.

For KYC, you can use any of the KYC documents given in the table below. Once the KYC is completed, you can continue using the Airtel IOT M2M SIM card with the GL868_ESP32. If you choose to submit the KYC documents later, you can access the KYC submission page by going to the SIM details page and then clicking on the View KYC button.

Required DocumentsAllowed Documents
Identity Proof- Aadhaar Card
- PAN Card
- Passport
- Driving License
- Voter ID

Circuit Digest Cloud SIM details page with the View KYC button highlighted for Airtel M2M SIM card KYC submission

Enter your mobile number to receive OTP.

KYC phone number linking screen for Airtel M2M SIM on Circuit Digest Cloud showing OTP input field

Once the OTP is verified, you will be asked to upload your identity proof. Select document type and upload front and back images.

Airtel M2M SIM KYC document upload screen showing front and back file upload options for identity proof on Circuit Digest Cloud

In the next stage, you will have to upload a live selfie. 

Note: Your browser will ask for camera permission; please click "Allow" to proceed.

 

Airtel M2M SIM KYC selfie verification process showing camera access prompt, live capture, and preview confirmation steps

Once the selfie is captured, provide your current residential address, and finally review your details, accept the consent declaration and click on Submit KYC Documents. The KYC verification will be done within 28-48 hours.

TIP: You have a 7-day window from the initial activation to submit these documents. We recommend doing it immediately to ensure uninterrupted service. "Allow" to proceed.

Step 3 ⇒Viewing Your Airtel IoT SIM Card Details

In the SIM card details page, you can see all the details related to your Airtel IOT M2M SIM card, like whether it's active or not, KYC status, ICCID and IMSI, start and end dates of your plan and the remaining time until your plan expires.

Circuit Digest Cloud SIM card details page showing Airtel M2M SIM active status, KYC verification, ICCID, IMSI, and plan expiry date

Step 4 ⇒ Setting Up SMS and Voice Whitelisting for Airtel M2M SIM

As per DoT regulations, IoT SIMs are restricted to communicating only with whitelisted numbers. So mobile number whitelisting is required to enable calls to and from the M2M number, as well as to send and receive SMS messages. With an Airtel M2M SIM, you can whitelist up to four numbers. To white list numbers, click on the Manage Whitelisting button on the SIM Card Details page.

Airtel M2M SIM whitelisting management screen on Circuit Digest Cloud showing SMS and voice number configuration options

In the Whitelisting Management page, enter the number you want to whitelist, select the type (Voice, SMS or Both) and direction(Incoming, Outgoing or  Both Ways) and click on Save Changes. The whitelisting will immediately take effect, and you can use the SMS and voice services.

Note: The Airtel IoT SIM card includes a 3-month promotional plan. After the promotional period ends, you can recharge the SIM card from here (link will be updated soon).

Airtel M2M SIM Whitelisting Options at a Glance

OptionChoices Available
Communication TypeVoice / SMS / Both
DirectionIncoming / Outgoing / Both Ways
Maximum NumbersUp to 4 mobile numbers
EffectImmediately after Save Changes

Frequently Asked Questions

⇥ Where can I find my Airtel M2M SIM card ICCID?
The ICCID is located on the package, with the SIM number listed as the SIM Number. If using GeoLinker GL868, insert the SIM and check the Serial Monitor; factory firmware will show the ICCID automatically when powered on. When you read the ICCID from the package, only enter the numerals and do not include the letter(s) at the end of the number.

⇥  How long does it take for Airtel to verify KYC (Know Your Customer) for M2M SIM Cards?
Airtel will complete verification of your KYC document submission through the Circuit Digest Cloud platform within 48 to 28 hours after submission. You may continue to use the SIM during this time, provided that your KYC document submission occurred within 7 days of the SIM's initial activation.

⇥  What is the maximum number of phone numbers that I can whitelist on the Airtel M2M SIM Card?
Whitelisting for up to 4 mobile numbers is available on your Airtel M2M IoT SIM. By using Whitelisting of each number, you also choose how you want to communicate (Voice, SMS or Both) and which way (Incoming, Outgoing or Both Ways). Whitelisting is effective immediately after you click Save Changes on the Circuit Digest Cloud dashboard.

⇥  Where can I find my Airtel M2M SIM card ICCID?
The ICCID is located on the package, with the SIM number listed as the SIM Number. If using GeoLinker GL868, insert the SIM and check the Serial Monitor; the factory firmware will show ICCID automatically when powered on. When you read the ICCID from the package, only enter the numerals and do not include the letter(s) at the end of the number.

⇥  How long does it take for Airtel to verify KYC (Know Your Customer) for M2M SIM Cards?
Airtel will complete verification of your KYC document submission through the Circuit Digest Cloud platform within 48 to 28 hours after submission. You may continue to use the SIM during this time, provided that your KYC document submission occurred within 7 days of the SIM's initial activation.

⇥  What is the maximum number of phone numbers that I can whitelist on the Airtel M2M SIM Card?
Whitelisting for up to 4 mobile numbers is available on your Airtel M2M IoT SIM. By using Whitelisting of each number, you also choose how you want to communicate (Voice, SMS or Both) and which way (Incoming, Outgoing or Both Ways). Whitelisting is effective immediately after you click Save Changes on the Circuit Digest Cloud dashboard.

Have any question related to this Article?