This repository contains the source code and design files for a Solder Plate Controller and detachable hotplate. The processor used is the ATmega4809 and is based on the work of DerSpatz. https://github.com/DerSpatz/PCB-reflow-solder-heat-plate
- 24V+ rated input voltage stage components allowing up to 24V to be used (Depending on powersupply trip option the "max" pwm needs to be lowered to not trip power suppply safety)
2.**Component Assembly:** Solder the components onto the PCB as per the schematic or choose a SMT assembly service like the ones from JLCPCB
3.**Power Supply Connection:** Choose a suitable power supply. 12V 5A tested, 24v 5A compatible. Use of more then 5A requires a appropriate FUSE to be chosen and solder on place of F1
The MCU can be programmed with JTAG2UPDI (https://github.com/ElTangas/jtag2updi). For programming, you need an Arduino with ATMEGA328p (Uno or Nano), some wires, a 4.7k resistor and a 10µF capacitor or 120 Ohm resistor to disable the auto-reset.
JCM from the Discord explained the process pretty good:
- Download/Clone this project: https://github.com/ElTangas/jtag2updi and rename the folder "source" to "jtag2updi" (otherwise the Arduino IDE won't like it)
- Open jtag2updi/jtag2updi.ino in your Arduino IDE
- Configure the flasher options for your Arduino Nano and flash it
- Connect D6 of your Arduino Nano over the 4.7kOhm resistor to the UPDI pin of the board and 5V to 5V and GND to 0V
- Add the MegaCoreX hardware package to the Ardunio IDE (see https://github.com/MCUdude/MegaCoreX#how-to-install)
- Select the options for the programmer **(Board: ATmega4809, Clock: Internal 16 MHz, BOD: 2.6V or 2.7V, EEPROM: retained, Pinout: 48 pin standard, Reset pin: Reset, Bootloader:Optiboot:Uart0(Defualt pins))** and select the port of your Ardunio Nano as Port
1. Order 100K NTC Glass thermistors Use for dev was : 100K Ohm Resistor NTC 3950-> https://www.aliexpress.com/item/32862228715.html?spm=a2g0o.order_list.order_list_main.11.1f0a1802Lw8YGL
2. Using either the potentiometer or soldering the resistor beside it choose the resistor reference value (2.5Kohm is standard)
3. You can modify the thermistor settings in Global.ccp file, it is all explained in there
5. Reccomended is 3 sensors on the bottom middle of plate all with 3 different refernece resistor values for accuracy across all temperature ranges and 1 thermistor held by a pair of helping hangs placed so the head touches somewhere on the PCB to be refllowed
6. Link to 2.0 inch TFT -> https://www.aliexpress.com/item/1005002363748586.html?spm=a2g0o.order_list.order_list_main.5.165d1802Amz1I7 (8 pin version) -> 7 Pin version can also be used
7. Link to 0.96 OLED -> https://www.aliexpress.com/item/32957309383.html?spm=a2g0o.order_list.order_list_main.17.662c1802iqqiSE (Choose OLD design SSD1306)
You can solder the thermistors directly on the hotplatte or use them with the connector. Please update the thermistor settings to the way you have them set-up.
Here are the defualt thermistor settings, The assume that the thermistors are soldered on the plate for 1,2,3:
Thermistors 6 on the connector number 5, touching the PCB to be soldered.
Thermistor thermistor1(THERMISTOR1_PIN, 2545, ThermistorZ_Placement::ON_PCB, ThermistorXY_Placement::MIDDLE); // -> 2545ohm set refrence -> This thermistor is set directly touching the PCB to be soldered
Thermistor thermistor2(THERMISTOR2_PIN, 9100, ThermistorZ_Placement::BOTTOM, ThermistorXY_Placement::MIDDLE_LOW_TEMP); //- > 9100 ohm set refrence Best accuracy around 90C -> This thermistor is used for the lower end of the temp scale
Thermistor thermistor3(THERMISTOR3_PIN, 2040, ThermistorZ_Placement::BOTTOM, ThermistorXY_Placement::MIDDLE); // -> 2.5Kohm best middleground
Thermistor thermistor4(THERMISTOR4_PIN, 564, ThermistorZ_Placement::BOTTOM, ThermistorXY_Placement::MIDDLE_HIGH_TEMP); //-> 564Kohm set refrence // 564R reference = Best accuracy around 210C
If you wish to only use the connectors use 2,3,4 and update the Globals .cpp to match your settings
The set resistence is measured between a GND point anywhere on the board and the LEFT pin of the connector with the thermistor UNPLUGGED and the MODULE POWERED OFF!!!!
you can measure and set those to the preset values or modify the values in globals.ccp to match your thermistors.
If a thermistor is set to bottom a automatic scaling factor for the difference difference in plate temp is set that was aquired through lots of datalogging and computations
If a thermistor is set to SIDE there is no scaling factor and will throw off the reading acorss the center of the plate (overall will be lower)
When using the Thermistor with placement "ON_PCB" That thermistor has a weighting factor of 10 and has the biggest effect on the read temperature.