I tried to copy a tutorial of a soldering iron whose control was based on arduino. After purchasing all the parts and assembling everything, it was time to upload the provided script. But when trying to do it the some errors appear and the member jfjlaros helped me alot and the script its fine.. But now i have another problem.. When I turn on the station, the iron does not stop heating until it becomes incandescent. I don't know that my connection is not correct or what type of component is not properly connected. Any suggestion ? Thanks
i used 2n2222 and not 2n2222a. And i also used arduino nano insted of a arduino mini pro ( keeping all connections on the respective ports ). Is that a problem ?
In the tip calibration menu instead of showing me what temperature the tip is at, appears xxx.
Apparently, xxx is printed when the temperature exceeds 1000 degrees. I suspect there is something wrong with the temperature reading. You might want to check the sensor connections and whether the sensor still works by monitoring pin A0.
I do not do well with commercials etc. I know you have no control but it helps if you can post an annotated schematic as you have wired it, not a frizzy picture. At that point hopefully I can help.
I already consulted the creator of this project or in this case the owner of the youtube channel where this project is. He told me that supposedly the error would have to be between the following transistors: 2N2222A , 2N2907 and the mosfet IRF9540
In the schematic the PNP transistor 2N2907 is written 2N29074. I don't know if it was a mistake in writing or if there really is a 2N29074
That is a 2N2907 with a mistype a small signal PNP It should work however I suggest you change the Zener to maybe 15V. It is there to prevent the circuit applying a 24Vgs to FET causing it to fail it is rated at +-20V. You could use almost any convenient part, I like the 2N4401 and 2N4403 as a complement pair (npn and pnp required but matching is not needed).
You will you will only get the emitter voltage plus about 0.7V on the base of when the transistor when it is turned on. If the arduino is putting out 5V you should see 5V at one end of R13 when on and about 0.7 plus the emitter voltage at the other end. Remember transistors are current controlled devices not voltage controlled devices like MOSFETs. If Q13 is on, the collector and base should be about 0.7, the emitter 0. When off the Emitter is still 0, the base is 0, and the collector is 24V. Hope this helps. I do not understand why R12 is there.
Hello. I built the circuit and I found some problems.
Most important one, the selection of the op amp. The code needs that @ 400C teh arduino or atmega to read 900 counts, out of 1023. This means your amp op must output 4.399 volts out of 5V supply. That demands a OP AMP with the capacity to output near rail voltage, like the AD822. Regular op amps(741, 358) have maximum output about VCC - 1.5V, or 3.5 Max @ 5V Vcc. The solution is to supply the op amp 6.5V.
R10 @ 100 ohms is too low. Replace it for 470 to protect the transistor 2n2907 from overcurrent.
I have a problem with the calibration routine. Everytime I reach the last calibration step the program freezes and does not record the calibration parameters and messes up with the cod in flash memory. Even after power down, teh arduino does not recover. I have to reflash the software again.
I tried to look into the code but could not identify any problem with the pointers in the calibration routine. My suspects are in line 1424 and 1425 of the arduino script.