Well all the projects I have had going recently have either been finished, or they are on hold waiting for a china order to come in. So I needed a cheap project to occupy my time. I decided to build a Nano Sumo Robot. The Nano class Sumo Robots have to be smaller than 2.5milimeters2 and weigh less than or equal to twenty-five grams. Getting the robot to be 2.5mm2 shouldn’t be that hard, but making the robot weigh less than or equal to twenty-five grams might be a problem (hopefully not).
Here’s the circuit I designed for it:
View attachment 17448
Most of the H-Bridges I tried out before this robot didn’t work, so I did some searching on the internet on why they didn’t work and how to fix it. I found a nice article (namely Here) that explained some stuff about them and showed some H-Bridge designs that work quite well. So I picked one out and tried it on the breadboard, and sure enough: it worked like a charm!
The robot uses U2 (a TSOP4038) to sense its opponent. The way it works is: the MCU sends out a 38 KHz IR signal, and when the other robot is in front of it, it reflects back to the TSOP4038 and tells the MCU that the other robot is right there.
The Power supply is just two CR2032 3VDC batteries in series fed through a 1N4007 diode to get about 5.5VDC. I hope they last more than 15 minutes with the robot running!
Here’s the code (NOTE: it is going to need some timing adjustments when the robot is built, and I don’t know just how well it works):
Code:
;*********************************************************;
;* <- START OF EPSILON CODE -> *;
;*********************************************************;
;*********************************************************;
;* This program is for the 14M2 on board of the Epsilon *;
;* Nano Class Sumo Robot. It checks the state of two *;
;* edge sensors on the front of the robot and also keeps *;
;* track of one IR sensor. The IR sensor is a TSOP4038 *;
;* and it is mounted on the front of the robot. It is *;
;* used for finding the other robot in the ring. The *;
;* program also sends out a 38KHz signal for an IR LED. *;
;*********************************************************;
;***********************PIN_LAYOUT************************;
;* PIN___FUNCTION || PIN___FUNCTION || PIN___FUNCTION *;
;* C.4 HB1 || C.2 HB2 || C.1 HB3 *;
;* C.0 HB4 || B.1 LDR1 || B.2 LDR2 *;
;* B.3 TSOP4038 || B.4 IR LED ||...[/quote]
[url=https://www.electronicspoint.com/projectlogs/nano-class-sumo-robot-%E2%80%93-picaxe.31/]Read more about this showcase item here...[/url]
I will change it now. 
