It's worth noting that the different pads don't actually have names, they just go through lots of iterations. They're numbered here so it's clear where the major upgrades were made.

Launch Pad 1.0

Scout V0.1 sitting on the pad on launch day

Launch Pad 1.0 was, predictably, the first pad built. It was powered by a Canon LP-E6 and 9v battery. I was a videographer at the time, filming on a 5D iii by Canon, so the LP-E6 was chosen simply because I had a few extras. The red button primed the countdown, while the green button locked it in. Ignition was accomplished via a mechanical relay, driven by an Arduino Uno. Two 9 gram servos at the top of the tower helped keep the rocket upright before launch.

Status: Scrapped for parts
In service: Oct 2015 - November 2015
Software: THROW_0.1 - THROW_0.5
MCU: Atmel ATmega328P
Computer Power: Canon LP-E6
Ignitor Power: 9v battery

Launch Pad 1.1

Scout V0.3 lifting off and separating from the pad comm wires

Scout V0.4 sitting, somewhat decapitated, next to Pad 1.1 before launch

The launch computer(left) and flight computer(right) during comm checks

The major improvements between Launch Pad 1.0 and 1.1 were the modifications to arming system, and addition of pad-rocket comm wires. The arming buttons were becoming clogged up with the exhaust from launch. They were replaced with a key and two toggle switches. The key put the pad into launch mode, the first toggle switch primed the count, and the toggle under the red hood engaged the count at T-10 seconds. The pad-rocket comm wires enabled the pad to halt the count if the rocket separated from the pad.

Status: Scrapped for parts
In service: December 2015 - March 2016
Software: THROW_0.6 - THROW_0.7
MCU: Atmel ATmega328P
Computer Power: Canon LP-E6
Ignitor Power: 9v battery

Launch Pad 1.2

Just after a failed ignition of Scout V0.7

Mid-construction of the articulating launch tower

Unsuccessful ignition of Scout V0.6's main booster

Pad 1.2 featured a new articulating launch tower, which made ignitor prep much easier while the vehicle was on the pad. Additionally, the tower clamps were beefed up, switching out the 9 gram servos for larger high-torque servos. The bent-metal tower clamps were replaced by PLA printed clamps that better hugged the rocket's airframe. Ignition power was upgraded as well, moving from a 9v battery to an 11.1v battery.

Status: Scrapped for parts
In service: March 2016 - September 2016
Software: THROW_0.7 - THROW_0.9
MCU: Atmel ATmega328P
Computer Power: Canon LP-E6
Ignitor Power: 11.1v battery

Launch Pad 1.3

Echo TV2 resting at an angle, waitng for ignitor placement

Liftoff of Echo TV1. The tower gantry pulls a black and white cable away from the flght computer to put it into flight mode

The four tower clamps from Pad 1.2 started to become a problem with vehicle design changes. Each clamp met with the rocket at a different point in the airframe, so onboard cameras, access panels, etc had to be very carefully placed on the vehicle. To fix this, Pad 1.3 moved the clamps back up top, also changing from solid PLA to a truss style. Pad 1.3 features a pad-rocket connection arm that disconnects about 1 second before launch. This helped start the rocket's PID control loop and data-logging just before liftoff. A tethered remote with arming and launch switches was integrated for safer operation, allowing for launch aborts without approaching the vehicle.

Status: Scrapped for parts
In service: September 2016 - February 2017
Software: THROW_0.9 - THROW_1.2
MCU: Atmel ATmega328P
Computer Power: Canon LP-E6
Ignitor Power: 11.1v battery

Launch Pad 1.4

Loose wiring test of the state indication LEDs

Although Launch Pad 1.4 used the same base and structure as 1.3, the conversion featured a myriad of upgrades. State indication LEDs, wireless countdown and control, dual port flame trench, etc. The two videos here show a bit of how the pad is set up. Frankly, several of these improvements were overkill. Pad-to-rocket I2C communication for sensor readouts doesn't make much sense at this scale, and wireless comm range was hindered by the radio being mounted too close to the ground. That said, it lasted quite a while, supporting over 10 launches on this revision alone.

Status: Retired
In service: February 2017 - November 2017
Software: THROW_1.2 - THROW_1.4
MCU: Freescale/NXP MK20dx256
Computer Power: 7.4v LiPo
Remote Power: Standard 9v
Wireless comm: Xbee Pro 60mW

Launch pad 2.0

The flame trench in three-core configuration during construction

Soot-covered launch clamps with the pad in the single-core configuration

Just before painting with heat resistant paint

Mounting a side hold-down clamp with the cover removed

As Launch Pad 1.4 began to become unreliable with wear and tear, the Falcon Heavy model was also being designed. Given that Pad 1.4 could never support a three-core vehicle, Pad 2.0 was designed from the ground up to support both single and three-core builds. With 8 total launch clamps, and an easily modifiable iron flame trench, Pad 2.0 is the most flexible platform yet. The Impulse launch computer has plenty of inputs and outputs to support add-ons like load cells, wireless comms, and any other peripheral that communicates through I2C or SPI.

Status: Active
In service: February 2018 - Present
Software: ImpulseSoft 0.0.1+
MCU: Atmel ATSAMD21
Computer Power: 7.4v LiPo
Ignitor Power: 11.1v LiPo