#4 DIY Phone Gimbal

My latest project involves re-purposing some old gimbal motors from a raspberry pi gimbal I designed a few years back.

In Part 1 I go over the main components and design & print the 2 arms connecting the roll, pitch and yaw motors.

Stay tuned for Part 2.

#1 Electronic Load

This is my first video, showing the electronic load I’ve been working on. There’s a cat involved so be sure to check it out.

Schematic here: https://easyeda.com/jeanlemotan/jlm-electronic-load

Firmware here: https://github.com/jeanlemotan/jlm-electronic-load

  • 0-4A (it was 5A in rev2, dropped now due to shunt de-rating)
  • 1mA, 1mV resolution. Accuracy should be similar if calibrated
  • 0-30V range. Can be increased by changing some resistors
  • 100W continuous with the recommended heatsink & FAN
  • 3D Printed case
  • Reverse polarity protection (opamp driven, improved from rev2)
  • 2 & 4 wire measurements (rev2 had only 4 wire)
  • Autoranging for both V&A using the ADS1115 PGA to get the max resolution/accuracy I can get from that part
  • Temperature sensing
  • Fan control (mosfet on pcb this time)
  • Fully programmable: it can execute a programmed sequence of operations and output the data through serial
  • SDCard for data saving (a csv per session)
  • 320×240 Touchscreen
  • Proper linear power MOSFET (IXTQ 42N25P)
  • Voltage reference REF3120AIDBZR (rev2 used PWM for this)
  • Precision DAC DAC8571IDGKR (rev2 used PWM)
  • Digital section on the PCB (rev2 PCB had no room for the esp32)
  • USB Powered (rev2 needed 3v3 input and +/- 12V for the opamps)

The software has the following features (some are WIP)

  • Voltage/Current/Power/Resistance display
  • Energy – both Wh and Ah
  • Graphs for the whole session
  • Constant Current/Power/Resistance Modes
  • SD card data saving
  • Time/Energy/Voltage limits