diff --git a/README.md b/README.md index ea7c874..8ddeb07 100644 --- a/README.md +++ b/README.md @@ -6,7 +6,7 @@ The aim of this project is to be able to use the 3-axis DJI gimbal with a custom ## Pinout identification -The Gimbal is composed of a flex PCB with a main connector and 3 smaller for each motor. The main end connector is a 40-pin mezzanine board to board connectors. In order to work easily I have designed a breakout board which open to a 2.54" header. +The Gimbal is composed of a flex PCB with a main connector and 3 smaller for each motor. The main end connector is a 40-pin mezzanine board to board connectors. In order to work easily I have designed a breakout board which open to a 2.54" header. (Kicad folder) Here is the strategy I followed to find the pinout: 1. Find all equipotential pins with a multimeter set to continuity tests, and test all the combinations @@ -33,7 +33,7 @@ Each motor is composed of two ratiometric linear hall sensors. (Texas Instrument -Ratiometric means that the output signal is proportional to the voltage supply to the sensor. In this setup, with 5V supply, the output measured is between 520mV and 1.5V, so a 1V amplitude. +Ratiometric means that the output signal is proportional to the voltage supply to the sensor. In this setup, with 5V supply, the output measured is between 520mV and 1.5V, so a 1V amplitude signal. ### 2. Measures @@ -101,6 +101,5 @@ To achive position control it is necessary to have first, a velocity controller ![Closed loop position diagram from SimpleFOC](docs/angle_loop_v.png) However, the motors of the gimbal have hard stop and can only rotate of around a half turn. It was so necessary to remove these mecanical stops. I drilled with a 1.6mm drill the two little holes to remove it. Then the motor was able to rotate freely and PID can be tuned. + - -