I am looking for a solution in terms of hardware and embedded software to meet the following requirements:

1. Receive bluetooth (classic) music i.e. from a smart phone, mp3 player etc
2. Play the bluetooth (classic) music through a single miniature speaker (mono)
3. Play voice prompts (stored in flash) which count down numbers at intervals based on altitude (which is measured using a pressure sensor)

4. If bluetooth music is being played when the voice prompt is triggered, the music will need to be temporarily attenuated.
4. Read pressure from Bosch BME280 sensor to calculate altidue (I2C or SPI interface).

Other gerneral requirements are:

1. Small form factor: As an example 60x50x15mm, although this is not fixed so there is room for some flexibility
2. Low power consumption
3. Powered by lithium battery with built in (wired) charging

I prototyped this project many years ago as shown in the diagram below...




However, the original prototype was too large and drained the battery too quick (partly due to an assembly/design fault I think)

I am looking to re-instigate this project using the latest devices available, but make it smaller and more efficient.

The WT32i is now obsolete so I need an alternaitve bluetooth module, but I was wondering if its possible to use the micro-controller on the bluetooth module to develop the software to meet the requirements above. I am trying to reduce the number of parts (such as external flash and CODEC) which will aid in reducing power consumption and package size.

 

Why can’t it just be a phone app? My iPhone has the pressure sensor.

 

Why can’t it just be a phone app? My iPhone has the pressure sensor.

1. Because it needs to fit inside a helmet with a speaker loud enough to be heard in freefall (wind noise)
2. Because I dont know how to write phone apps
3. Because I dont know how accurate the pressure sensor is to calculate altitude