DPS3005 PSU Module and MODBUS RTU Python & Arduino

I recently came across a DPS3005 PSU Module with PC control option , i have used similar modules before in a bench power supply and was impressed with the results . With the launch of a new version that included PC control i decided to order one ! (Banggood.com)

The PC / bluetooth was not mentioned in the supplied instructions and the pc software (windows 7+ only) was available from the sellers listing and also Manufacturers Youtube Channel.

Without giving up and i decided to look on the manufacture’s download link and found a interface datasheet, all in Chinese . Using google translate i was able to see the command set and the interface was basically listed as Modbus Rtu, rs232,9600 baud and slave address 1.

I have no experience with modbus at all and had to do a bit of research to understand this very basics .

The following functions were listed as supported in the datasheet:
0×03 – Read data from one or more registers
0×06 – Write a single register
0×10 – Write multiple registers

basic Functions extacted from datasheet , needed for examples below
Voltage set – Register 0×00
Current set – Register 0×01
Voltage measured – Register 0×02
Current measured – Register 0×03

power on – Register 0×04

Loads more see manufactures datasheet for more info…

# DPS3005 MODBUS Example By Luke (www.ls-homeprojects.co.uk)
# Free to use this code how you like but please link my site
# Requires minimalmodbus library from: https://github.com/pyhys/minimalmodbus

import minimalmodbus

instrument = minimalmodbus.Instrument(‘COM4′, 1) # port name, slave address (in decimal)
instrument.serial.port # this is the serial port name
instrument.serial.baudrate = 9600 # Baud rate 9600 as listed in doc
instrument.serial.bytesize = 8
instrument.serial.timeout = 0.5 # This had to be increased from the default setting else it did not work !

instrument.mode = minimalmodbus.MODE_RTU #RTU mode

print instrument.read_register(2, 2) #read a range of 16-bit registers starting at register 2 to 3 (measured voltage and current)

Bench power supplies are an indispensable tool when prototyping electronics. Being able to set custom voltages and having some sort of current limiting feature are key to making sure that the smoke stays inside all of the parts. Buying a modern bench supply might be a little too expensive though, and converting an ATX power supply can be janky and unreliable. Thanks to the miracle of USB-C, though, you can build your own fully-featured benchtop power supply like [Brian] did without taking up hardly any space, and for only around $12.

USB-C can be used to deliver up to 100W but is limited to a few set voltage levels. For voltages that USB-C doesn’t support, [Brian] turns to an inexpensive ZK-4KX buck-boost DC-DC converter that allows for millivolt-level precision for his supply’s output.

https://www.youtube.com/watch?v=Xdq6dzH26QY