USING JP1.X INTERFACES WITH JP1.3 REMOTES
Posted: Mon Oct 22, 2007 7:42 pm
It turns out there's a slight difference in configuration of the 6-pin interface connector of JP1.3 remotes compared to JP1.2 remotes. Without going into boring technical details, the JP1.2 insists that you leave pin 5 normally high, but the JP1.3 insists that you leave it low. Full-blown JP1.x interfaces (i.e., those that work with JP1.1 remotes as well as JP1.2 remotes) have pin 5 normally pulled high. If you plug one of those into a JP1.3 remote the processor is immediately switched into a "tool" mode and will not communicate serially. Those members who have been uploading, downloading, and dumping JP1.3 remotes all this time were only able to do so because of a stroke of luck --- their interfaces did not have the JP1.1 components installed.
It's easy to deal with this problem:
If you are not using a JP1.3 remote you need read no further.
If you are NOT using a JP1.1 remote, but want your interface to work with both JP1.2 and JP1.3 remotes, just make sure the circuit to pin 5 of your interface is disabled, either by omission of the three JP1.1 components, or simply by clipping wire 5 where it is connected to the edge of the interface board. (Use fingernail clippers if necessary.)
If you are using a JP1.1 remote, the circuit to pin 5 is necessary, but it won't interfere with also using the interface with JP1.2 remotes.
The combination that has a conflict is if you want to use your interface with both JP1.1 and JP1.3 remotes. If you are one of the extremely rare individuals with this need, just cut off pin 5 of the 6-pin header inside the JP1.3 remote (NOT the JP1.1 remote). Don't worry. You will NEVER have any use for that pin. In fact, if it weren't for the damned JP1.1 we would never have designed any interfaces that used pin 5.
Tommy
It's easy to deal with this problem:
If you are not using a JP1.3 remote you need read no further.
If you are NOT using a JP1.1 remote, but want your interface to work with both JP1.2 and JP1.3 remotes, just make sure the circuit to pin 5 of your interface is disabled, either by omission of the three JP1.1 components, or simply by clipping wire 5 where it is connected to the edge of the interface board. (Use fingernail clippers if necessary.)
If you are using a JP1.1 remote, the circuit to pin 5 is necessary, but it won't interfere with also using the interface with JP1.2 remotes.
The combination that has a conflict is if you want to use your interface with both JP1.1 and JP1.3 remotes. If you are one of the extremely rare individuals with this need, just cut off pin 5 of the 6-pin header inside the JP1.3 remote (NOT the JP1.1 remote). Don't worry. You will NEVER have any use for that pin. In fact, if it weren't for the damned JP1.1 we would never have designed any interfaces that used pin 5.
Tommy
HOLY MOLEY!