Jason (Tse-Kang) Wang
How to make (almost) anything!

Week 11

output devices

This week: add an output device to a microcontroller board you've designed and program it to do something.

Since I already controled normal hobby servo last week, I decide to try control the motors I need for my final project.

I get into learing how to use TTL communication to use XL-320 smart servo. This week's goal is to use what I learned from last week to move the servo according to the angle data I read last week.

I milled the FTDI ver. of SatshaKit board I modified, and also make a shield for it, since to control XL-320, I need some hardware to do half-duplex.

Xl320 Half Duplex Board File!!!

Xl320 Half Duplex Schematic File!!!

Arduino code for moving the servo.

Xl320 shield

For my board to do half duplex communication, I use 74LS241 to connect rx/tx into half duplex. For controlling the motor, I found a liabrary that will help at controlling the motor.

The top left is the xl320 motor shiled I designed to control XL-320 motor. The botton one is the analog duplex shield from last week, and the right one is my modified version of FTDI satshakit board.

Milling the modified version of satshakit.

Here is the connected morotrs and the board. The main mcu is on the other side of the body. Notice the lack of 74LS241 chip on the shield. Interestingly enough, apparently there are ways to do half duplex without 74LS241. Two ways I would like to try if I have time, connect rx/tx with an resistor in the middle, or connect tx directally into the mortor signal line.

In conclusion, The motor is actually easier to control than I think, and it's a really good intro unit to learn how to control smart servo.