Watch Dogs: all 16 QR code locations, hidden messages, gangster assault rifle, read-only Trophy

Now we're shown you how to complete the single-player campaign, here's the locations of all the QR codes,

There are plenty of QR codes distributed across the Watch Dogs map, each of which can be scanned with a camera to unlock an audio log, as well as other codes that can be scanned with the Watch Dogs smartphone app.

So if you want to know how to unlock the Gangster Assault Rifle and the bonus mission that unlocks the Read-Only Trophy, follow the instructions below.

QR Code 01 - South Parker Square

You can find this code above the Food & Liquor building near an intersection. Go down the street to the south of the building and hack a low hanging camera that's above two garage doors. Turn it north and scan the code. If you scan the QR code to the left with your smartphone, it will reveal the following hidden message from G1gg1L3s 01.
Hidden Message: Hey DedSec! ┌∩┐(◣_◢)┌∩┐

QR Code 02 - North Parker Square

This isn't far from the Food & Liquor store above. As you approaching from the south, you'll see the code on the right hand side next to a For Rent sign. Go down the alley to the left before you reach the QR code. The camera is on the corner of the historical building on the left side of the alley. Scanning this QR code with your smartphone to reveals another hidden message.
Hidden Message: DedSec can suck my 8=====>

QR Code 03 - West Side of The Wards

You'll need a boat for this code. Go to the dam near the west end of The Wards. You'll see the code if you look from west to east.There's a camera on the dam that you can hack and you can scan the code. Use your smartphone to scan the code on the left of your screen for the hidden message.
Hidden Message: Don't QQ if U can't find me.

QR Code 04 - South End of The Wards

This QR code is a near a gun store what you need to approach from the west - if you go past it you've gone too far. The camera is on the south side of the rad, way up on an old apartment building. Hack it and turn it to the east to scan the code, then use your smartphone for another hidden message.
Hidden Message: *\0/* U found one! *\0/*

QR Code 05 - West Brandon Docks

Go to the southwest end of the bridge on the large Tidis building. On the east end of the bridge you can hack the camera on the corner of the building. Scan the QR code, use your smart phone to find another hidden message.
Hidden Message: DedSec? More like DedSUC!

QR Code 06 - East Brandon Docks

This code is on the side of the building with the Safe Energy Saves You Money poster. Go to the gas station near the northeast of the building and you'll see a camera on a light post. Scan the code then use your app for the message the message.
Hidden Message: Mark IV style muthaf*cker!

QR Code 07 - Central Brandon Docks

Now go over to the nearby train platform. The station is to the east of the QR code which sits to the side of another Tidis building. From the west stairs up to the platform, hack the camera that is positioned on the corner of the building. Scan the code and use you app for the follow:
Hidden Message: (^._.^) U can findz QR codes!

QR Code 08 - North Brandon Docks

Go to North Brandon Docks and head east past two buildings. The camera that needs hacking is on the corner of a building. The QR code is on the left.
Hidden Message: U R getting WARMER

QR Code 09 - South End of The Loop

Go below the train platform just to the east of the QR code. Near the north stairs that lead to the platform you'll see a camera that can be hacked on the wall to the east. Scan it use your app for the secret message.
Hidden Message: Can U find D rest?

QR Code 10 - Southwest End of The Loop

Drive below the freeway and you'll be on the north west shore nearby where the rivers meet. The camera is under the freeway, so hack it and aim it towards the southeast to see the QR code under the freeway. The hidden message is next to it.
Hidden Message: BadBoy17? Bad, BOY, 17? Really?

QR Code 11 - Northwest Island of The Loop

Get on the train platform and wait for trains to pass before jumping on the tracks and heading north west. follow the bend and there's a platform on the right-hand side. Climb on the platform and hack the camera on the wall. Point it towards the QR code and the hidden message is next to it.
Hidden Message: Itz all 4 d GIGGLES!

QR Code 12 - Northeast End of The Loop

You can't miss this one. It's bang in the middle of a 4-way intersection of an alley. Stand in the middle of the intersection then head north east and hack the camera on the wall. Scan the QR code and point your smartphone at the monitor on the left for the hidden message.
Hidden Message: G1gg1L3s... 1L... IL... Get it?

QR Code 13 - South Central Area of Mad Mile

Head to the west of where the code is located and you'll see a camera up high in the wall of a building, just across the street of the Chicago Water Tower. There are two cameras here but you want the one that pieces the code together to the west. Decipher the QR code with your phone again.
Hidden Message: How U finding these? ಠ_à²

QR Code 14 - Northwest Area of Mad Mile

This is right next to one of the fat travel points. Go to the parking lot where there's a garage door that can be hacked. On the building on the right hack the camera above the door to scan the QR code.
Hidden Message: U must werk out.

QR Code 15 - Southwest Area of Mad Mile

Position yourself on the west of the code across the street. You'll see a camera up on a wall. Point it East to scan the QR code which is positioned on the right of a advert with a car on it. The QR code for your smartphone is on the left of your screen.
Hidden Message: o_O O.O O.o O_ﾃｳ

QR Code 16 - Pawnee

Theres' only one code in Pawnee. Drive on to the broken bridge and hack a camera on a light post. Look towards the billboard and scan the final QR code. If you use a smartphone here it will unlock the Gangster Assault Rifle.
Hidden Message: ~~(8:> will U be my BFF? 4 realz!

Bonus Mission - Hack G1gg1L3s

As you collect the 16th code you'll be called by DedSec. go to the marker on your map and you'll go back to the Mad Mile. Look for the intrusion box on the side of the building and hack it, then get ready to break into the security system.

Back to Watch Dogs walkthrough: all missions, hacking and access code guide