arduino-fingernail_2024-02-22_19-28-29

 
Arduino development board, smaller than a fingernail, weighing only 0.3g! (Open source hardware), this might be the smallest Arduino development board you can find!
1. Disclaimer: This small open-source solution was actually developed a long time ago, but I felt it was somewhat unnecessary to release it before! I thought that people with some hardware experience wouldn't need or even consider this open-source hardware solution, and complete beginners would be better off buying a ready-made one. Therefore, fearing criticism from both experts and beginners (please, both gods, have mercy!), I kept putting it off. However, I did promise fans in previous video comments and private messages to open-source this hardware, and considering the needs of the Butterfly project from Mechatronics, weight reduction is still very meaningful, so I decided to release it for those who need it, hoping it can help those who require it.
2. Hardware Solution Introduction: This is a minimal system development board based on the ATMEGA328P-MMHR, with an ultra-small size of 10mm×10mm. The board integrates a 5V, 1A LDO, supporting 2S~3S lithium battery input (2S lithium battery recommended). Since it was initially designed for a micro ornithopter flight control system, an SBUS reverse circuit is also integrated. Two versions of the board were designed and prototyped, both supporting hardware interfaces and both ISP and serial port download methods (the newly prototyped board requires ISP method to download the bootloader; you can search for specific download methods yourself).
① One version has all pins brought out through 1.27mm pitch half-hole pads, suitable for use as a micro Arduino development board in space-constrained applications;
② The other version only brings out some pins: serial port, SPI programming pins, and two multi-function I/O ports, suitable for micro ornithopters. PB3 and PB4 can be used to control the two servos of the ornithopter, and PB5 can be used as the PPM signal input. SBUS pin pads are also brought out.
3. The prototype board has been simply verified; programming works correctly. See the attachment for details!