This repository contains the source code and design files for a Solder Plate Controller and detachable hotplate. Processor used is ATmega4809 and is based on the work of DerSpatz: https://github.com/DerSpatz/PCB-reflow-solder-heat-plate
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
Same process as DerSpatz Solder plate (Direct quote):
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)
- Install the Adafruit_GFX, Adafruit_SSD1306, DallasTemperature and Debounce2 libraries with the Library Manager (you might not need all of them depending on which firmware you plan to use)
- Download and open the ino you want to upload to the ATMEGA4809 (https://github.com/DerSpatz/PCB-reflow-solder-heat-plate/blob/main/Firmware/pcb_reflow_fw/pcb_reflow_fw.ino)
- 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
4. Attach the sensors to the hotplate using High tem Kapton Tape
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
These settings are measured between a GND point anywhere on the board and the LEFT pin of the connector with the thermistor UNPLUGGED
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.