ESP32 Digital Control Power Supply

ESP32 digital control power supply is a portable digital control adjustable voltage regulated power supply based on ESP32 and buck-boost chip. The sampling voltage signal on the feedback pin of LM5175 (cheaper than LM5176) buck-boost chip is controlled by TM8211DAC chip and op amp to realize output voltage control, and the voltage and current are sampled by INA226. Then it is controlled and driven by ESP32 to display the parameters. The fast charging output is independently controlled by SW3516H. TYPE-C and TYPE-A (100W) two-way fast charging interface automatically identifies the output
1. DC interface input supports 9~30V/1-8A input. Only one of the two input interfaces can be used, and the input power must be greater than the output power 
2. TYPE-C input is induced by CH224K fast charging to a maximum of PD100W (20V/5A) input. It also supports common protocols such as QC
3 USB communication TYPE-C input interface is only used for serial communication and one-key program download and burning 
4. XT60 port adjustable output 2.5~50V/0~8A (limit 120W) Normal cooling defaults to 50W output 
5. TYPE-C and TYPE-A interface output power maximum 100W (VIN>28V) Two-way fast charging interface automatically identifies output
6. Display parameters using ST7735 0.96-inch TFT 80*160 RGB display 
7. Rotary encoder and multi-function button for parameter setting and function switching
8. Support NTC temperature measurement and input voltage measurement Reserved cooling fan power interface
 
Adjustable output detailed parameters
Voltage output range: 2.5V~50V Because of the output PMOS switch turn-on threshold voltage and LM5175 feedback voltage, only a minimum output voltage of 2.5V can be achieved Voltage
output accuracy: 20mV
Voltage measurement accuracy: 10mV
Voltage adjustment step: 1mV
 
Current output range: 0~8A The maximum output of 8A is based on heat dissipation considerations. The actual current can be added, but the shunt resistance value needs to be adjusted.  Current
measurement accuracy: about 1mA
. Current adjustment step: 1mA.
 
Output power range: 0~120W. Conventional heat dissipation defaults to 50W. If you want to use it for a long time at high power, you must do a good job of heat dissipation. Forced air cooling is required.
Power measurement accuracy: 10mW.
Power adjustment step: 1mW.
 
Basic function mode.
Main function mode: detailed display mode, simple display mode, parameter calibration mode. Switch by right-clicking the multi-function button. Long press the right button to switch the display direction. 
Set parameter selection: voltage, current, power, calibration switch, etc. Switch
parameter setting mode by left-clicking the multi-function button: Select the set number of digits by rotating the middle button of the encoder. Move the encoder left and right to add or subtract values.
Adjustable output switch: In display mode, control the switch of the output PMOS by the middle button of the multi-function button. Calibration  
selection mode: Switch the voltage and current to be calibrated with the left button of the multi-function button, and enter the reference parameters through the parameter setting. Adjust to the calibration display position and press the middle button of the multi-function button for calibration. Constant
current protection mode: When the output current is greater than the set current, it will enter the constant current state. The current is constant and the voltage is pulled down. However, the hardware constant current control effect is not very good, and the device will be in a hiccup state.
Overcurrent protection mode: When the output current is greater than the set current, the output will be turned off.
Other protection modes: When the output power is greater than the set power or the temperature exceeds 50°, the output will be turned off. Program
 
download
program is based on Arduino IDE development and related libraries are added. Connect the data line. Select ESP32 and the corresponding serial port to compile and upload.  
There are two versions of the program 3.0 and 3.1. The current protection mode of version 3.0 is to turn off the output switch when the output current exceeds the set current. The  constant current
protection mode of version 3.1 is to start DAC constant current control when the output current exceeds the set current. However, the constant current control effect is not very good, and the hardware constant current will affect the maximum current output function.  
The program and functions are not very perfect. I may upgrade it when I have time. The program and dependent libraries are in the attachment.
 
Note:
PCB proofing 4 layers are 90mm long, 49mm wide, and 1.6mm thick. The component parameters are based on the schematic diagram. The components that Jiali Chuang does not have are on Taobao. The relevant software and hardware information are in the attachment.
The ESP32 CNC power supply is mainly composed of the main control PCBA, PCB shell and M2 copper column screws. The whole machine is about 90mm long. 49mm wide and 20mm high. 
There are two different versions of PCB shells. It is up to your choice. It is best to use an aluminum substrate and a thermal conductive silicone pad to fit tightly between the power MOS and the aluminum substrate to assist in heat dissipation.
If you need to use it for a long time at high power, you must do a good job of heat dissipation.
It is best to use forced air cooling. There is a reserved function on the hardware, but I did not develop it because the voltage and current sampling voltage divider resistors and shunt resistors have certain errors. Before the first use, it is best to calibrate with an external high-precision voltmeter and a constant current load. 
   6. This CNC power supply project is not perfect and there are still some problems. It is open sourced in the hope that we can improve it together so that everyone can use a powerful and cheap CNC power supply.