I have excellent experience with Embedded Systems Either using Microcontrollers (STM32FXXX, NXP LPC17XX, TIVA-C, ARDUINO DUE, ARDUINO MEGA, MSP430, ESP32, ESP8266) or Single Board Computers (RPI, Orange pi, Nano PI, UDOO, HIKEY 960, Tiny Rex, Beagle board black, Beagle Board X115).
But I am mainly using STM32 as main for me in most of my projects, I already used the following STM32F103, STM32F107, STM32F215, STM32F407, STM32F411, STM32F429, STM32F446, STM32F469, STM32F769, STM32L422, STM32L432, STM32L072.
I own many nucleo, Discovery and EVK for these MCUs.
I have used different IDEs with STM32, I am using mainly two Keil-5 and Cube-IDE but I used also IAR, Atollic and ECLIPSE. I use both C and C++ for programming and writing Codes.
I built many Drivers for the Peripherals and even without using HAL Lib and many drivers sensors and Actuators.
I own great and powerful tools for debugging (Segger Trace - Segger PRO - Logic Analyzer Saleae PRO - Fluke Oscilloscope), That make debugging and development easier.
For BLE, I used BLE in different Projects using different BLE chips (ESP32 - TI CC2560 - DA14583). I used BLE to make ble communication between either two chips or chip and Mobile APP. I know how to use BLE and I used TI CC2560 for BLE, so I can use CC2541.
Honestly for The ECG chip, I didn't use it before but it is not big deal to use it. I can write the driver for it.
We can discuss more if you want.
Thanks for reading my proposal.