SMARS robot with USB rechargeable battery

thingiverse

This is a redesign of SMARS with a rechargeable battery that can be charged via USB. The charging module adjusts the output voltage to match the Arduino board and motors, allowing for a minimum voltage of 7v from the DC input required by a regular Arduino UNO board. In my case, I have two 6v motors, so I set the output voltage to 6.3v and connect the supply voltage to pin Vin instead, bypassing the serial diode that lowers the required voltage for the Arduino board to 6.3v (7-0.7) while still allowing the regulator to work properly and provide a 5v output. You can recharge the battery from the USB port on the side without removing it, but the slide switch needs to be turned on during charging. Alternatively, you can connect the switch to the output of the charging board instead, which may consume a little bit of energy when the switch is OFF. Space is tight, so take care with cables and wiring. Using hot glue can be helpful. I use the WeMos D1 board, which allows me to control the robot via Wi-Fi from my smartphone. Part list: - 1x Arduino UNO or WeMos D1 ESP8266 board - 2x N20 motors (6V 150 or 200 RPM) - Adjustable step up lithium battery charging integrated module https://www.aliexpress.com/item/32998389598.html?spm=a2g0s.9042311.0.0.34e44c4dnylIg4 - 1x 503450 lithium-ion battery 3.7V 1000mah (size 50x34x5 mm) - 1x Dual H Bridge Motor driver https://www.aliexpress.com/item/32944408444.html?spm=a2g0s.9042311.0.0.bb094c4dPNtmON - 1x mini slide switch https://www.aliexpress.com/item/32859663187.html?spm=2114.search0604.3.14.349c7461npBSca&s=p&ws_ab_test=searchweb0_0%2Csearchweb201602_7_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536%2Csearchweb201603_53%2CppcSwitch_0&algo_expid=be07d9b5-bf68-401c-9225-568a880b562b-2&algo_pvid=be07d9b5-bf68-401c-9225-568a880b562b