ESP32 Forum

Hello,
I am new to ESP32 and Bluetooth development. I've an application that I want to develop as described below and need some guidance on the module / development kit selection that would be best suitable for the application as described below, and how to start preparing simple application which will be interfaced with host microcontrollers on both, Master & Slave units for data exchange.

I am looking for a pair of BLE modules for data exchange. The Master unit will have a BLE module interfaced with Host Microcontroller. This module will establish pairing with a wireless foot pedal with another BLE module and host microcontroller interface on the foot pedal board. Both devices have PIC18F series microcontroller and support UART communication with the BLE modules.
There is no PC / mobile device involved in the communication at this point.

Both devices need to enter pairing mode and the unit should be able to pair with any foot pedal in field.
Once paired, both devices will exchange data.
Foot pedal will be battery operated - 2 AA Alkaline batteries - non rechargeable.

Which module should be used for such application?
Can you please provide some guidance how to setup and develop such application? Is this strictly based on AT Commands which will be interfaced over UART with host microcontroller?

Thank you for your support!

Dear Espressif team,

Thank you for your reply.

When using AT Commands, I would like to achieve the following in my application:

1. Main unit being Central Role and User controlled foot pedal being a Peripheral Role in a Point-to-Point Communication. Both ends will have a Host MCU exchanging data using BLE modules – simply as a “Cable Replacement”.
2. For Scanning, Advertising, Pairing and to configure parameters like Slave Latency, I will need to use AT Commands, right?
3. Once the link is established, both modules will need to function in a “Transparent Mode” without AT commands and just simply to transfer user defined Data packets between Host MCU over UART bus.
4. Does the module ESP32-C3 provide such Transparent Mode – as a “Virtual Serial Port (VSP)” to provide communication with Host MCU and work in simply a “Cable Replacement” Mode?
5. Can you please provide me specific AT Commands structure which I will need for my such application?
6. What would be the structure of such AT Commands and how to exit from AT Command mode and use in a Transparent mode for simple data exchange once the link is setup?
7. How long the peripheral (battery operated) module can sleep without breaking the link to save power?
8. Upon power-up, how quickly a Peripheral can setup link with a scanning central and transfer the first activation user defined packet for the unit to start activating?
9. Is there any FAE with whom, I can discuss my application and technical questions if I get into any difficulties during prototype design?

Would such application possible in AT Command Firmware mode?

Thank you.

Dear Espressif team,

Thank you for your reply.

As I was thinking about my application, I’ve an additional question as below and would appreciate your response.

Does ESP32-C3 module come pre-installed with the Bootloader and AT firmware, or do I need to install or update any firmware before using AT Commands over UART from the host MCU?

Please note that in my application, ESP32-C3 modules on both, Central (Main unit) and Peripheral (Foot Pedal) ONLY interface with the host MCU UART bus and does not provide any interface with a commuter USB port.
Both ESP32-C3 modules will need to be configured to exchange data in UART-BLE Passthrough mode only via AT commands from the host MCU. Would this be feasible?

Thank you so much.