# CNC Blue — CNC GRBL Control via Bluetooth

> iOS Bluetooth controller for Arduino CNC machines, with G-code generation. (iPhone/iPad app by Mehmet SIMSEK.)

- Source: https://appshunter.io/ios/app/cnc-blue/id1507725632 (this page in markdown: same URL + `.md`)
- Developer: [Mehmet SIMSEK](https://appshunter.io/developer/740675946)
- Category: Utilities, Productivity
- Price: $2.99
- Rating: 2.50/5 from 4 App Store ratings · 4 written reviews indexed
- Age rating: 4+
- Requires: iOS 13.5 · 1 MB
- Languages: English
- Released: 2020-06-06
- Data updated: 2026-07-07
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/cnc-blue/id1507725632/reviews.md

## What is CNC Blue?

You can control 3 axis of your CNC milling machine which connected Arduino CNC shield with a suitable bluetooth module for iOS device at baud rate 9600.

The application has G code build function modules which are circle, polygon, star, rectangle, arc, draw, gear and spiral modules. 

Some modules has cut inside and cut deep functions. 

You can select cut tool diameter.

Draw module is another fantastic mode to allow to you can use on milling what you draw on the screen with selectable depth of cut function. Before use this function you have to calculate your CNC working area to fit your drawing to this area.

All these modules can capable record builded G codes to a file with module name.For save G codes you have to open "save all calculations to files" switch from setting menu.
 You can share builded G codes. 

And you can send received Gcode to Arduino via bluetooth with send page, only load the received .nc file.

All builded G codes automatically transfer send page, you need to touch send button to start cnc milling, application will send your Gcode to Arduino via bluetooth connection which you done from the application.

You can share with airdrop, e-mail etc. all .nc files on the Files page.  

And polygon, star, rectangle, arc, draw,  gear, spiral modes has 3D view function to show you what you build in 3D view .

*IMPORTANT: The CNC Blue application has Stop button, but FOR YOUR SAFETY YOU HAVE TO USE YOUR OWN EMERGENCY STOP BUTTON WITH WIRE CONNECTED TO YOUR ARDUINO CNC SHIELD in case of needed to use.*  

Why I need to change baud rate to 9600:
The application baud rate 9600. Because of that we need to change baud rate of Grbl from config.h file to correctly communicate with Grbl via bluetooth module.

How you can set baud rate to 9600;
You can find the Arduino Grbl "config.h" file from "documents/arduino/libraries/grbl/config.h" and change baud rate to #define BAUD_RATE 9600

How to connect your bluetooth module to Arduino CNC shield :

Bluetooth module "TX" to Arduino CNC shield "RX",
Bluetooth module "RX" to Arduino CNC shield "TX",
Bluetooth module "VCC" to Arduino CNC shield "3V3",
Bluetooth module "GND" to Arduino CNC shield "GND" 

Pins must be connected correctly to protect your Arduino-CNC shield and bluetooth module.

## Key features

- 3-axis CNC control via Bluetooth
- G-code generation for shapes (circle, polygon, star, etc.)
- Custom drawing to G-code conversion
- 3D preview of generated designs
- Save and share G-code files
- Direct G-code sending to Arduino

## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/cnc-blue/id1507725632/reviews.md

### 4/5 — GRBL

*2024-10-11*

It works wonderfully. I can control a GRBL CNC using an HC-06 BLE (Bluetooth module). However, you need to program the module once via PC or Mac beforehand, which means assigning a name and password. It’s easy to do. I hope there will be updates again soon.

### 1/5 — Not connecting to BLE

*2022-09-13*

It didn't work for esp32 boards as it use BLE for connections. Money got wasted.

### 3/5 — Hopefully it can

*2021-07-13*

Be configured for 152000 baud rate instead. That’s what my cnc uses. That’s what my Bluetooth module has. Is there a way to do that?

### 5/5 — Plasma cutter fix

*2021-07-10*

Works great, easy to use. I used Bluetooth and the app to fix problems with high frequency start interference from plasma cutter through usb. Bluetooth connects easily once set up.

## Frequently asked questions about CNC Blue

### What is CNC Blue?

CNC Blue is a mobile application for iOS devices that allows you to control your 3-axis CNC milling machine via Bluetooth. It enables the generation and sending of G-code directly to your Arduino CNC shield.

### How much does CNC Blue cost?

CNC Blue is a paid application and costs $2.99. There are no in-app purchases or advertisements within the application.

### Does CNC Blue have ads?

No, CNC Blue does not contain advertisements. It is a paid application that offers an ad-free experience for controlling your CNC machine.

### What devices is CNC Blue compatible with?

CNC Blue is designed for iOS devices, specifically iPhones and iPods. It requires a Bluetooth module connected to your Arduino CNC shield for communication.

### How often is CNC Blue updated?

The latest version of CNC Blue is 1.03, which was last updated on June 19, 2020. The initial release date was June 6, 2020.

### What is the age rating for CNC Blue?

CNC Blue has an age rating of 4+, making it suitable for a wide range of users. This rating indicates general suitability without mature content.

### Can I use CNC Blue offline?

While the app itself can be used for G-code generation and file management offline, sending G-code to your CNC machine requires an active Bluetooth connection to your Arduino.

### What is the baud rate requirement for CNC Blue?

CNC Blue operates at a baud rate of 9600. You will need to configure your Grbl firmware to match this baud rate for successful communication via Bluetooth.

## Version history (last 4 releases)

### 1.03 — 2020-06-19

- Loop inside switch added to Rectangle module to make PCB Antennas (HF, VHF, UHF, SHF bands)
- Loop inside function round the corners automatically to keep the signal quality high.
- First open fill inside switch to use loop inside function.
- Application gives Antenna length and full wave frequency on the info page to adjust length of antenna
- This module builded for HAM RADIO operators, 73's

### 1.02 — 2020-06-16

- Spiral module added to cut spiral shape, 
- Spiral direction switch added (Clockwise or Counterclockwise)
- Spiral opposite switch added to turn the spiral opposite side

### 1.01 — 2020-06-09

- TX label view options modified
- G code receive to Files minor bug corrected

### 1.0 — 2020-06-07

No release notes.

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## More apps by Mehmet SIMSEK

- [VDP SIMULATOR](https://appshunter.io/ios/app/vdp-simulator/id745124884)
- [Time Calculator 4 Aviators](https://appshunter.io/ios/app/time-calculator-4-aviators/id1028656384)
- [CNC Blue Plus](https://appshunter.io/ios/app/cnc-blue-plus/id1514892319)
- [MorseUs](https://appshunter.io/ios/app/morseus/id6763133426)

All apps by Mehmet SIMSEK: https://appshunter.io/developer/740675946

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-07.*