Latest 0.1.0
License MIT
Platforms ios 8.0

CI Status



fz-iOS-sdk is available through CocoaPods. To install
it, simply add the following line to your Podfile:

pod 'fz-iOS-sdk'

Add "libfz-iOS-sdk.a" file in "Linked Frameworks and Libraries".

For Swift users:

  • Set "Defines Module" to "YES" in "Build Settings" tab after the pod install.


While using, a library instance should be created as follows:

BlueTooth *mBLEComm;

@interface ViewController : UIViewController

The Above created instance can be instantiated in .m file in viewdidload() or wherever needed as follows:

mBLEComm = [BlueTooth sharedInstance];

There are some delegate methods which can tell us about the various fuctionality which are being performed. We need to add the notification observer for that. Below is the code:

- (void) loadNotification

[[NSNotificationCenter defaultCenter] addObserver:self


#pragma mark - Notification

- (void) disconnectedFromDevice:(NSNotification*)notification
// Called when device gets disconnected

To scan the device, bluetooth must be switched on.

Following are the steps to initiate scanning and connecting to Fret Zealot:

-(void) scanDevices
[mBLEComm startScanDevicesWithInterval:2.5 CompleteBlock:^(NSArray *devices)
[deviceArray removeAllObjects];
for (CBPeripheral *per in devices)
if(![deviceArray containsObject:per])
if( > 4 && [[ substringWithRange:NSMakeRange(0, 4)] isEqualToString:@"Fret"]) // Only shows fret devices
[deviceArray addObject:per];
NSLog(@"address %@",[per.identifier UUIDString]);

if (deviceArray.count==0) {

} else {
// You can show the list in UItable View
[deviceTable reloadData];

And in order to connect to a device, the following method needs to be called:

CBPeripheral *device  = [deviceArray objectAtIndex:selectIndex]; // Select from UItableView
NSString* address = [device.identifier UUIDString];
NSString* devName =;

[mBLEComm connectionWithDeviceUUID:address TimeOut:5 CompleteBlock:^(CBPeripheral *device_new, NSError *err)
if (device_new)
NSLog(@"Discovery servicess...");
[mBLEComm discoverServiceAndCharacteristicWithInterval:3 CompleteBlock:^(NSArray *serviceArray, NSArray *characteristicArray, NSError *err)
NSLog(@"Device Connectednn");
currentDevceAddress = address;
currentDevceName = devName;

NSLog(@"Connect device failed.");


Once the instance is ready, we can use the following methods of the library to send commands to Fret Zealot.
All the commands are held in a command buffer. This means that the commands are collected into a buffer prior to getting sent. A command buffer can hold a maximum of 5 commands. To insert a command into the buffer, various methods can be called as shown below.

Also, the parameters commonly used are:

string – Strings are numbered from the thinnest string (index 0) to the thickest (index 5). The tuning is read from the 5th string to the 0th string: E-A-D-G-B-E. Hence, the string indices would be as follows:
E=5, A=4, D=3, G=2, B=1, E=0

fret – Frets are numbered starting at 0 for the open string. In our case "fret" param has a maximum value of 14.

red, blue and green – These are the values for the LED color. Possible values for each can be between 0 and 15.

intensity – The intensity(brightness) of the LED. Possible values are between 0 and 10.
fadeMode – The fade effect with which to light up the LED.
Possible values for fadeMode are between 0 and 4.

Fade effect reference chart:

Fade Mode Value          Description

0                 Fade not active    //Set Pixel On **Most Common**
1                 Fade in short      //Fade in Pixel over 50ms
2                 Fade in long       //Fade out Pixel over 50ms
3                 Fade out short     //Fade in Pixel over 200ms
4                 Fade out long      //fade out Pixel over 200ms

There are several methods for controlling LED state on the fretboard

The set method – This method lights up a single LED

[mBLEComm set:(int)fret withPixel:(int)string withRed:(int)red Green:(int)green Blue:(int)blue withIntensity:(int)intensity withFade:(int)fadeMode]

The set_across method – This method lights up all the frets in a string

[mBLEComm set_across:(int)string Red:(int)red Green:(int)green Blue:(int)blue withIntensity:(int)intensity withFade:(int)fadeMode];

The set_all method – This method lights up the whole fretboard with the LED color supplied as arguments.

- (void) set_all:(int)R Green:(int)G Blue:(int)B withIntensity:(int)intensity withFade:(int)fade;

The set_subset method – This method lights up a string from a given fret to the 14th fret. For example, if you need to turn on the LEDs from fret 8 to fret 14, this is the method for you. However, the upper limit (14) cannot be changed.

- (void) set_subset:(int)Strand_start withPixel:(int)Pixel Red:(int)R Green:(int)G Blue:(int)B withIntensity:(int)intensity withFade:(int)fade;

The clear method – This method sets each LED on the fretboard to off. This counts as one command of the 5 allowed in the command buffer

- (void) clear;

There exist several utility methods for inteacting with the command buffer. The command buffer holds 5 (five) serialized commands,
and mirrors the size of the Bluetooth MTU. This structure does not need to be initialized.

The sendCommandClear method – This method clears the buffer of any existing data, and should be invoked before each write to the fretboard.

- (void) sendCommandClear;

The sendCommandFlush method – This method dumps the contents (up to 5 commands) of the command buffer to the BLE device

- (void) sendCommandFlush;

Commands should be wrapped in these utility commands, to ensure delivery to the Fret Zealot
A typical command to set completely new pixels — (C) major Triad in Standard Tuning

[mBLEComm sendCommandClear]; // Flush the buffer
[mBLEComm clear];           //Clear all displayed Pixels
[mBLEComm sendCommandFlush];  // Write commands to the Fret Zealot

[mBLEComm sendCommandClear];          // Flush the buffer

[mBLEComm set:3 withPixel:4 withRed:0 Green:0 Blue:15 withIntensity:10 withFade:0]; // Set 'C' to blue

[mBLEComm set:2 withPixel:3 withRed:0 Green:15 Blue:0 withIntensity:10 withFade:0]; // Set 'E' to green

[mBLEComm set:0 withPixel:2 withRed:0 Green:0 Blue:15 withIntensity:10 withFade:0]; // Set 'G' to blue

mLib.sendCommandFlush();                // Write commands to the Fret Zealot

The isConnection method – This method returns boolean value true if fretboard is connected with application and false
if fretboard is not connected with application.


Light Show

The set_display method – This method takes strand_start, Intensity and fade_mode as parameter
and light up on fretboard according to parameter fad value.

strand_start :

intensity : LED intensity on fretboard


fade_mode                      Description

0                                    No lights
1                                    Sparkler
2                                    Bolt
3                                    Rainbow
strand_start = 4;

// fadValue can be any between 0-3

[mBLEComm sendCommandClear];
[mBLEComm setDisplay:strand_start withIntensity:10 withFade:fadValue];
[mBLEComm sendCommandFlush];


edgetechlabs, [email protected]


fz-iOS-sdk is available under the MIT license. See the LICENSE file for more info.

Latest podspec

    "name": "fz-iOS-sdk",
    "version": "0.1.0",
    "summary": "Connect your app to FretZealot via fz-iOS-sdk",
    "description": "This SDK helps to scan, connect and perform actions on FretZealot.",
    "homepage": "",
    "license": {
        "type": "MIT",
        "file": "LICENSE"
    "authors": {
        "edgetechlabs": "[email protected]"
    "source": {
        "git": "",
        "tag": "0.1.0"
    "platforms": {
        "ios": "8.0"
    "source_files": "fz-iOS-sdk/Classes/**/*"

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