JP1 Remotes

The development build RM/RMIR v2.06 build 9 includes a new version of the jp12serial library. Version 0.23 of jp12serial is required to support remotes whose data area (aka EEPROM or E2 area) is not a whole number of flash erase pages. At present the only known remote with this property is the URC-7955, whose data area is four bytes short of two 0x800-byte erase pages. As with recent earlier versions of jp12serial, this version supports 32-bit and 64-bit versions of Windows, Linux and Mac OS X.

As jp12serial is used by other programs than RM/RMIR, the latest version is available here. The link is to the repository on SourceForge, where both binaries and source code will be maintained. Users of RM/RMIR are reminded that each build of RM/RMIR v2.03 and later includes the relevant version of jp12serial, so they should update RM/RMIR to newer builds as they are issued, rather than separately updating the jp12serial version in their installation.

Link to announcement of jp12serial v0.22.

The development build RM/RMIR v2.07 build 6 includes version 0.24 of the jp12serial library. It has been found that uploads with RMIR via a JP1.x cable fail with certain newer computers and/or remotes when using version 0.23 of jp12serial. Version 0.24 fixes this issue.

The link to the latest version in the post above now takes you to the binaries and source files of version 0.24.

RMIR v2.12.5, which has now been officially released, includes version 0.25 of the jp12 serial library. This adds support for the GreenPeak GP541 processor first seen in the URC2068BC2. This processor is slow in reading and very slow in writing, so suitable delays have been added that are active only when the remote has this processor.

Such remotes are identified by the signature starting with 68. The other remotes that have been seen that have a signature with a first digit of 6 are those with a Texas Instruments processor, either the CC2541 or CC2530. These all have a signature starting with 60. Version 0.25 uses this second digit to distinguish these two cases, to ensure that there is no change of behaviour for remotes supported by earlier versions of jp12serial.

Both the source and binaries of jp12serial are now maintained on SourceForge, so the latest version can always be found here.

RMIR v2.13.0, which is the current official release, includes version 0.28 of the jp12serial library. Since that release, a USB-to-Serial converter that uses an FTDI chip has been found that causes RMIR to crash when used with 64-bit Java in Windows 10, though not with 32-bit Java or with non-Windows OS. See this and following posts for more details.

The cause of the crash appears to lie in an interaction between Java and the FTDI driver that is outside the control of RMIR and which occurs only in a rare combination of circumstances. It does not seem to affect most interface cables that use an FTDI chip. Nevertheless I have found a work-around that avoids the problem and have created version 0.29 of jp12serial with this fix. This will be included in the next release of RMIR, but it is available here now for anyone who wishes to update their installation of RMIR v2.13.0.

I have posted a beta version of jp12serial v0.30 for testing. This is a substantial revision that is intended to handle all interface designs and processors, including legacy transistor interfaces, and also all wiring combinations and all remotes. This beta version is available only for Windows, and it should be used as a replacement for the included version in RMIR v2.13.0. I should like to hear of any combination that it does not work with, or any additional USB-to-Serial processor chips that expose at least one of RTS and DTR, whether or not it works with them.

Here are some notes, first for USB-to-Serial interfaces.

1. The 6-pin connector should be wired with Pin 3 = GND, Pin 4 = TXD, Pin 6 = RXD. Pin 2 can be either RTS or DTR. If Pin 2 = RTS, which is the most common situation, then in RMIR set Remote > Interface to JP1.X Serial. If Pin 2 = DTR then set it to JP11USB. With these connections it supports all remotes from JP1.2 upwards, so excluding only JP1 and JP1.1 remotes.

2. USB-to-Serial converters are supported with all processors of which I am aware. It has been tested with FTDI FT232R an FT230X chips, Prolific PL2303, Silicon Labs CP2102N and the CH340G. The only qualification is that CP2102N needs to be revision A02 (those produced later than June 2019) and needs a 10K pull-down resistor connected between TXD and GND, which needed to be added to the interface board I bought, but other boards may already include it.

3. It has been said for years that the Prolific chip does not work with JP2 remotes, which are those with a MAXQ processor. With this revision of jp12serial, a Prolific cable works with ALL remotes, including those with a MAXQ processor.

4. There are a few variants of the connection scheme described in note 1. If RTS and DTR are both available, then with both Pin 2 = DTR and Pin 5 = RTS, all remotes except JP1 are supported. This is the only connection that supports JP1.1 as well as all of JP1.2 upwards. JP1.1 remotes can be supported if only one of RTS and DTR is available, by connecting that to pin 2 and connecting pins 3 and 5 together, so making pin 5 also GND. This wiring scheme supports all from JP1.1 upwards other than JP1.2, and both JP1.1 (which it works with) and JP1.2 (which it does not) need the batteries removed and replaced to restore normal remote operation.

Now a few notes concerning legacy transistor interfaces used with a serial port.

1a. In addition to the univeral connections to Pins 3, 4 and 6, transistor interfaces also have a connection to pin 1. A 4-transistor interface has Pin 2 connected through the interface to DTR and Pin 5 to RTS. A 3-transistor interface may have Pin 2 connected either to RTS or DTR. In all cases, Remote > Interface in RMIR should be set to JP1.X Serial.

2a. A 4-transistor interface with Pin 2 connected to DTR, Pin 5 to RTS, supports JP1.1, JP1.2 and JP1.3. It cannot support JP1.4 or later due to the nature of the connection to DTR. A 3-transistor interface with Pin 2 connected to DTR supports only JP1.2 and JP1.3, but one with Pin 2 connected to RTS can be treated the same as a USB-to-Serial converter with Pin 2 = RTS, so it supports all remotes from JP1.2 upwards, and also JP1.1 if Pins 3 and 5 are connected together.

Finally, all configurations support JP1 used with a JP1 EEPROM Adapter, either a commercial one or an Arduino programmed as one.

The release version of jp12serial v0.30 is now available and is incorporated into RMIR v2.13.2. It is unchanged in function from the beta version described in the post above, but binaries are now available for all supported OS. The source files and all binaries are also available here, a link which will always take you to the latest official release.