I have OSCAR II espresso machine, and where this machine is a heat exchange machine that has one boiler for espresso extraction and steaming.
The problem is that this machine heat up until boiling temperature, and provide this temperature for espresso extraction and steaming too, which shouldn't be in this way.
The espresso extraction temperature should be around 92 degrees celsius and steaming should above 100 degrees celsius. And what happens is that the machine heat up above 100 degrees and there I should do my espresso shot and also during extraction the temperature falls down, which means there's no PID control and that causes sourness in the espresso shot.
In this case I better modify this machine or buy a double boiler machine which costs like + $1700.
I can sell my OSCAR II and save money and buy a double boiler machine.
I thought that if I can modify the machine and save myself buying more expensive machine that costs double the price of the OSCAR II.
So what do you think guys?! Is that a good idea?
I know for sure that I can hack a lot of things, but I for sure too that I need knowledge and experience.
For this project I think I need to do the following:
Take the signal of the boiler and take it to a microcontroller board like the Attiny85 which would be super cheap mod part.
I need to know what controls the temperature of the boiler, and if the boiler is controllable or not.
Add two buttons: one for espresso brewing, the 2nd for steaming.
When choosing espresso brewing, the temp falls to 92 degrees and stay there, when extraction starts, there should PID control to keep the temp at 92.
The same for steaming, if steaming temp is like; for example, 110 degrees, then when just choosing the steaming button, then the boiler heat up until that temp and stay there.
Other functions; like, measuring the water level that already has a sensor, controlling single or double shot brewing would be not be so difficult to program with the help of you guys.
So what you think? Any suggestions?