Heart rate monitor designed in KiCad, using Nordic Semiconductor NRF51822 bluetooth module and TI AFE4400 heart rate module.
The repository contains a KiCad design of a 5x5 cm heart rate monitor breakout board. Some libraries were borrowed from Guan Yang's github projects (https://github.com/guanix/boards). Also, some design aspects of the circuit were inspired by HackManhattan Nordic nrf51822 beakout board (http://dangerousprototypes.com/2013/05/19/hackmanhattans-nordic-nrf51822-breakout-board/)
In addition to AFE440 for heart rate measurements and NRF51822 for BLE communications, the circuit also contains a Freescale MMA8452 3-axis accelerometer, CAT24M01 1Mb EEPROM and an additional heart rate circuit composed of just a few simple elements (see bottom center of the schematics). The circuit was inspired by this article and presents a cheaper and simpler option to AFE4400.
Image of manufactured PCB
Components were soldered with reflow technique. Some joints had to be manually corrected using soldering iron
