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My attempt on Severin popcorn maker
srolija
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Posted on 07/29/2015 7:46 PM
I'm planning on building roaster using popcorn as well. Idea is to use TC4/TC4C for control and monitoring using Artisan. I have read many posts and tutorials on this forum and web generally but still have some questions. I also looked on schema of TC4 and went trough aArtisan source so I wouldn't ask repetitive questions. So I really tried not to ask already answered questions.

Idea

What I would like to do is use TC4 to connect to Artisian and read measurments (ET, BT, inlet - ambient and exhaust temperature) and to control DC fan (on OT2 or IO3) and heater (on OT1) using either potentiomenters (via ANLG1 and ANLG2) manually or via controls using Artisan (just two sliders/multiple buttons). Additionally it would be great if I could use PID with just heater (and manual fan set to fixed speed to keep beans rotating and still allow heater to reach required temperature) instead of manual mode if I wanted. Additionally I may add LED which would indicate whether it is in manual or PID mode (probably on DIO4/5 since they are not connected to anything).

I have attached schema how would I do it (since I couldn't find how to embed it in post).

Some questions

I do know more electronics than "starter Arduino user" but I would not consider myself too advanced. So I'm still not sure on many thigs so here are the questions:

1. Am I missing something in given diagram? After reading following note https://tc4-shiel...E-aPWM.txt I'm not sure should I add optotransistor (such as 4N25) in place of red transparent box? Or would it be just fine as it is?

2. Since motor draws significant amount of current, should I add large capacitor between GND and +18V to prevent reseting of Arduino or would it be better to just power Arduino trough USB (and along remove yellow box and connect common ground)? Current capacitors around motor are beacuse on original PCB they were also there (I supose to remove noise to pass EMC test, more on that: http://hydrarapto...light.html ).

3. After reading few tutorials on the web (that use TC4), I haven't seen anyone using pulldown resistors on OT1/OT2, and on TC4 schematic for IO3 there isn't one. So should I add them to ensure that everything is off before Arduino starts (or I connect it to PC)?

4. Could I use custom library for LCD on I2C ( LiquidCrystal_I2C) just by adding required code to aArtisan or it would require modifications because of PCB (on schema it seems as if they are just routed out to be more accessible)? So I suppose it shouldn't be a problem.

5. Is it possible to use ANLG1 and ANLG2 with aArtisian 3.10? While looking over source code I couldn't find anything related to them besides code in util/aPWM? So I would guess that it isn't possible.

6. Is it possible to use OT2 instead of IO3, since user.h contains definitions for MIN_OT2, OT1_CUTOFF and OT2_AUTO_COOL. And since I would like to control DC motor (which as far as I know should be connected to IO3) I don't see anywhere where it could be configured for that case?

I'm sorry if some of these questions were already answered, I really tired to find answers before asking. smile

Tomorrow will post how initial popcorn roaster looked and how it is wired. Then when I manage to resolve all issues regarding to questions will order missing parts and when they arrive (could be few weeks since I'm from Europe) will post how it goes.

Sergej
srolija attached the following image:
schema.png
 
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