how many bytes can be sent at one time by notification?

[ericzhao]

Hi,

I'm writing a program on nrf51 that needs to send a lot of data through notification. How many bytes can be sent at one time? And is the nrf51 capable to read the sensor(i2c) 100 times in one second? Thank you!

Best Eric

[bjorn-spockeli]

Hi Eric,

Q1: The amount of data that can be "notified" is dependent on the BLE packets payload size. Thus, with the nRF51 the maximum payload size is 20 bytes since the S130 SoftDevice does not support the Data Length Extension(DLE) feature.

Q2: Yes, it should be possible to read data from a sensor connected to the I2C bus at 100Hz. The TWI peripheral of the nRF51x22 has maximum SCL clock frequency of 400kHz.

Best regards

Bjørn