Some of you may be aware that I have been planning to offer a “Pro” version of the XTBM this fall. The two main enhancements will be a logging history that can be scrolled through, and a more comprehensive display of noise information. Its release is contingent on availability of a new PIC with expanded memory. The original XTBM PCB was designed to support both PICs. Now that complete data is available on the new PIC, it unfortunately turns out not to be totally pin-compatible with the present PIC. The Microchip application engineer seemed surprised when I pointed that out to him. As a result, the next PCB has several pinout changes to support the new PIC, and a new firmware version is necessary to accommodate those changes in the current XTBM.
Firmware version 1.05 will automatically configure itself for either PCB version when power is first applied. The configuration status is stored in nonvolatile memory, and is normally only rechecked on request. Since the PIC goes through many power cycles as the XTBM is moved from outlet to outlet, the watchdog timer can also force a reconfiguration and self-test if the PIC does not initialize properly after a power cycle.
Version 1.05 has no significant operational changes, but a few "rough edges" have been addressed.
One issue reported by a number of people is that the XTBM would occasionally report a self-test failure, probably due to a nearby “unfriendly” load. Since it is not necessary to do a self-test every time the XTBM is plugged in, version 1.05 only performs the self-test the first time the unit is powered up. It will repeat the self-test each power cycle until it has passed. After that, the self-test can be performed by issuing a P ALL_OFF command during the first second after the XTBM is plugged in. Self-test now displays the test status (both pass and fail) when it completes.
I have received two LCDs that had a column of dots not functioning properly. To make it easier to catch that type of defect, a row of solid boxes are displayed on the second row of the LCD while the self-test is running. (It turns out the fix for that defect is to just simply tighten the clamping tabs on the back of the LCD assembly so to make better contact between the LCD PCB and the display itself.)
The other change is that the noise alert status is now only displayed when programmed with the P ON/OFF commands at power-up so the XTBM will begin making measurements slightly quicker. Note that the alert reporting is disabled by default when the unit is reinitialized by running the self-test.
Except for those changes, version 1.05 works the same as 1.04. A PIC with firmware version 1.05 is now available to those of you who would like to keep your XTBM current.
Jeff