About

A electronic dummy load with external pc control

• Scheme (pdf)
• Software

Serial control protocol

Here's documentation of the serial commands used to control the load

serial parameters :

• 9660 8N1
• end line : LF (\n)

Commands (upper or lower case) :

• D: display actual values (mA), dutyCycle, fan
• S xxxx: set current value (mA)
• +,-: push button
• T: display internal temperature
• F xxxx: set fan speed (0-255)
• H,?: show help

Answers :

command D :

S: NNN
R: NNN
D: 0xNNN
F: NNN

With :

• S : set current (mA)
• R : read current (mA)
• D : set duty cycle (0x0-0xFF)
• F : fan speed (0-255)

Command T :

T: NN.NN

With :

• T : atmega internal temperature (°C)

Links

• sources on github
• (detailled) blog post (in french)

Pictures

almost Final

During testing

During testing

bottom case layout

top case layout

perfboard construction

perfboard construction

finakl

pwm control

final construction

final construction

Published on  June 1st, 2015