Pairing code digits

[sam]

Dear Sir, We are developing our BT device using the 51822 DV. Our problem is - the pairing code is preset to 6 digits but our LCD display only be able to show 4 digits, please tell me how we can change the pairing code from 6 to 4 digits?

Thanks, David

[Hung Bui]

Hi Sam,

By spec the passkey must have 6 digits.

There are 2 options that I can suggest:

• Try to use your 4digit LCD to display the 6 digit key. You can either let the digit circling/sliding to the left to display the whole 6 digit (4 at a time) or display each time 3 digits

• Use static passkey, so that the first 2 digits can be chosen, say 00, for example, and you generate 4 digits randomly in the application code. After that you feed that 6 digit (00XXXX) passkey to the softdevice. On the peer device you can tell user to use 00 at the begining before typing the 4 digit (XXXX) displayed.

[Stephen]

These are both bad solutions. The correct solution is

1. Set the s110 bluetooth stack an option that indicates that the passkey is 4 digits.
2. the s110 bluetooth stack accepts this, and when the user enters a 4 digit passkey the device properly authenticates.