Thank you for the suggestion. Based on information in that app, I am now even closer to the solution. I can now open communications channels over SPP between the Android and the MSP430, but only with the Android as the client and the MSP430 as the server. In my application, I need things to be the other way around. I think it is an issue of UUIDs and/or open channels. Now, when I try to connect from MSP430 as the client, I see the ACL connection event at the Android, but the socket is not accepted.
I have succeeded in opening the channel using the MSP430 as the server side, using the "well-known" SPP UUID, which is 00001101-0000-1000-8000-00805F9B34FB. It seems likely that the remaining problem is to use SDP look-up to identify the channel at the Android that corresponds to that UUID. There seems to be no way to get this information from the Android, so that will have to happen via bluetooth using SDP.