Having a fully automated cotton candy vending machine in your possession is a great thing, but not if you do not have full access to its software. With [Block’s Retro Repairs] getting ghosted by the manufacturer on regaining account access to the machine he bought used for $300, there was little left but to try and break into the system.We previously covered the journey in getting the vending machine back into a state where it’d actually reliably produce cotton candy again, a process which is quite tedious and temperamental. After a lot of fiddling with sensors and temperature settings this was fixed, but still left the issue that as a vending machine it should allow the owner to set prices and such. Sadly this could only be done remotely via a special account, which access to had been left with the previous owner.Despite the very custom exterior, the vending machine runs what is effectively an Android system, consisting of an industrial computer board wired into a lot of stepper drivers and other control boards. To the extreme delight of everyone involved, it was possible to access the Ct Terminal application with adb and its product database on the device’s storage. Unfortunately writing back a changed database file didn’t change anything in the UI, so for a few months the project languished.After nearly bricking the system and ending up factory resetting the control software including temperatures, it actually improved the performance of the machine and produced cotton candy, so that was one win. Ultimately the solution was to modify the original app, but a combination of weak coding skills and the app being in Chinese led him to use free LLM coding chatbots to assist here.This resulted in a custom settings menu being added with the ability to modify pricing, no need for online access any more and a very nice cotton candy vending machine for the private arcade where presumably friends and family can enjoy cheap or even free cotton candy. Finally having the machine sealed against ant intrusion was also a major improvement.