As with any project there are things you could do better. Many of the issues are related to the firmware, notably:

• Current sink level needs smoothing to provide a more stable value
• Related to the current sink level, the fan just turns on and off when the current goes above or below the hard limit of 0.5A rather using a high point to turn on and a low point to turn off to prevent this.
• Display isn't well utilised

And with that comes possible improvements!

• Add thermistor to heat sink for fan control (I have one also obtained from the power supply)
• Utilise a 4.096V regulator for micro controller power (and hence the analog VRef)
• Add incoming voltage measurement (much of the electronics is already in place for this)
• No support for timing load (eg detect a sudden drop caused by an over loaded power supply)

However for now the unit does what I need it to do (sink a fixed amount of current). Unless I find some of these issues annoying (fan maybe) I'll leave this project as is!