Maximum ADC rate for transmitting data using Bluetooth to PC

[Ahnsei Shon]

I would like to know what is the maximum ADC sampling frequency for transmitting data over Bluetooth to PC.

I am using two modules having an nRF52832 for each module. 

One is a remote module sending 2CH ADC data and another is a data receiving module connected to a PC. 

I need to send 2CH ADC data from a remote device to a PC through Bluetooth with a maximum sampling rate, but 10Khz sampling will be enough. 

2CH ADC data were transmitted with a sampling rate of 1kHz through Bluetooth. However, increasing the sampling rate was not possible for me.

Therefore, I would like to know the 2CH of maximum ADC sampling frequency which can be sent from a remote module to a PC. 

Also, I would like to receive a sample code for this if possible.

 

[Edvin]

Hello,

The theoretical maximum throughput on a BLE link is ~800kbps using 1Mbps, and ~1.3Mbps using the 2Mbps PHY, as you can see here:

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsds_s140%2FSDS%2Fs1xx%2Fble_data_throughput%2Fble_data_throughput.html&cp=3_4_2_0_16

In reality, you can expect the numbers to be a bit lower than this. It also depends on whether your computer (or bluetooth dongle) supports the 2MBPS PHY. 

So the maximum number of samples per second depends on the size of your samples are, and how you send them. 

To maximize the throughput, you should gather up many samples, so that you can send large packets. Larger packets means a lower header to payload ration, but that depends on the latency requirements on your application.

I don't have any sample code, but it should be fairly simple to use the ble_app_uart example, and add the adc functionality from the saadc example.

Best regards,

Edvin