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IanHarvey / bluepy

Python interface to Bluetooth LE on Linux
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setMTU() function not working? #228

Open Cooper-Weng opened 7 years ago

Cooper-Weng commented 7 years ago

My BLE peripheral device is "Nordic NRF52832". And I refer to #113 reply, want to use the notification to receive more than 20 bytes at once, but it not working.

I have to change the BLE_GATT_ATT_MTU_DEFAULT value to 247 in "nRF5 SDK ble_gatt.h", and in RPI3 have to setMTU(247), and RPI3 can receive more than 20 bytes.

But this setting is not a regular way and sometimes it caused "Nordic NRF52832" occur error event and disconnect.

mobilinkd commented 6 years ago

Confirmed. setMTU() works in the sense that the new MTU is properly negotiated with the device but fails because bluepy only sends and receives 20 bytes at a time after the MTU is changed.

After setting the MTU, I can see the MTU properly negotiated with my device and the device sending 100+ byte packets. But the data provided to the Python application by bluepy is truncated at 20 bytes.

fellerts commented 6 years ago

I have this issue as well, using the nRF52832. As mobilinkd said, I see that the MTU negotation happens as expected, and the device sends 100+ bytes, but all data received from bluepy is 20 bytes long.

Firefox2005 commented 5 years ago

Did anyone find a solution or a workaround for that? Sending my data in 20 bytes packages takes forever with a write with response.

ghost commented 5 years ago

I am facing the same problem, working with a Scale I send 8 bytes the scale responds with a 34 bytes, did anyone find a solution to read that many bytes?

sterwen commented 5 years ago

Same problem found on my side. Any news since the last comment ? I have put additional traces in bluepy-helper, but the problem is not coming from that layer. The function that receive the notifications already gets a truncated payload. bluepy-helper.log