Thank you for the positive feedback. You may see in other replies that since Heljan are not fixing the old firmware, I have had to ensure that every other digital address on my layout avoids all of the TT address multiples. This approach works and does stop the sudden random moves.
Thank you for a very informative video. You are lucky to have got so far in terms of in depth programming. I recently installed this model for a friend and encountered a magnitude of issues including; Err1, rotating in a uncontrolled manner, incorrect indexing and yes I tried various fixes, all to no avail. The unit was returned to the supplier (its less than 2 months old) and I await a replacement unit. It is such a shame since the model is a cracking representation at a reasonable price when compared with other turntables.
Hi Nigel. Err occurs when the bridge is removed, say for cleaning, while power is still on the unit. This is a big design weakness as the unit should not be so vulnerable. Imagine if your locomotives blew their DCC chip every time you removed them from the track! I also ended up causing this error within a couple of months of owning my Heljan TT. As for the random movements, since Heljan have been made aware of the issue, but show no signs of updating their firmware, I have had to exclude all of the multiplier addresses above the TT's address range from every other device on my layout.
This happens because of a buffer overflow in the firmware; it uses a data type for storing the incoming ID that only has 256 combinations, so when any number higher than that goes in, it wraps around and starts back from 0 (256). It was never compatible with the new digital system; it technically works as intended according to the old 8bit-ID system. This can be fixed in 1 or 2 ways; either they make a firmware update (but that might not be possible if the already very limited micro-controller is near it's limits, and it most likely is as it's probably some 30byte-ram jellybean), or somebody provides a conversion module or at least firmware for a micro-controller, to filter out data for addresses past 255; could be done with one of those $1 ATMEGA8 boards and a transistor. Maybe there's already -I bet this happens due to lack of filtering either on the turn tables power line or data line. Try putting a capacitor across the positive and negative right outside the input to the turntable, that should eliminate potential dips in voltage caused by other devices (eg. train power surging on startup), something that commonly make digital devices glitch and read wrong data; normally each IC chip on a board have their own dedicated decoupling capacitor, to make sure they don't interfere with each other; look up that term on Wikipedia. Also try adding a 1-10k resistor from the data line at the turn table to ground; noise might be coming in from there. I think it's highly unlikely this is a firmware issue; not only am I an electronics nerd, I'm a programming nerd, and making an ID mistake in software is basically impossible even for a beginner, and I suspect they aren't beginners. Lack of filtering is very possible though even for good circuit designers, lots of things to miss accounting for.- And then I continued watching...
Thanks, Martin. I notice that your TT turns at a descent speed to each programmed stop. My Heljan 89121 moves slowly. Is there a speed adjustment procedure for this TT, please?
Hi, there is no speed setting or speed adjustment for this TT. The only thing to check is that the unit is totally free to rotate without brushing past anything, and that it is receiving all the power that it needs from your supply. There is not much else that you can change.
Thanks you! This explains the my Turntable's sudden moves very clearly !
I must congratulate you on your very clever sleuthing! Im sure this will be very helpful indeed.
Thank you for the positive feedback. You may see in other replies that since Heljan are not fixing the old firmware, I have had to ensure that every other digital address on my layout avoids all of the TT address multiples. This approach works and does stop the sudden random moves.
Thank you for a very informative video. You are lucky to have got so far in terms of in depth programming. I recently installed this model for a friend and encountered a magnitude of issues including; Err1, rotating in a uncontrolled manner, incorrect indexing and yes I tried various fixes, all to no avail. The unit was returned to the supplier (its less than 2 months old) and I await a replacement unit. It is such a shame since the model is a cracking representation at a reasonable price when compared with other turntables.
Hi Nigel. Err occurs when the bridge is removed, say for cleaning, while power is still on the unit. This is a big design weakness as the unit should not be so vulnerable. Imagine if your locomotives blew their DCC chip every time you removed them from the track! I also ended up causing this error within a couple of months of owning my Heljan TT. As for the random movements, since Heljan have been made aware of the issue, but show no signs of updating their firmware, I have had to exclude all of the multiplier addresses above the TT's address range from every other device on my layout.
This happens because of a buffer overflow in the firmware; it uses a data type for storing the incoming ID that only has 256 combinations, so when any number higher than that goes in, it wraps around and starts back from 0 (256). It was never compatible with the new digital system; it technically works as intended according to the old 8bit-ID system. This can be fixed in 1 or 2 ways; either they make a firmware update (but that might not be possible if the already very limited micro-controller is near it's limits, and it most likely is as it's probably some 30byte-ram jellybean), or somebody provides a conversion module or at least firmware for a micro-controller, to filter out data for addresses past 255; could be done with one of those $1 ATMEGA8 boards and a transistor. Maybe there's already
-I bet this happens due to lack of filtering either on the turn tables power line or data line. Try putting a capacitor across the positive and negative right outside the input to the turntable, that should eliminate potential dips in voltage caused by other devices (eg. train power surging on startup), something that commonly make digital devices glitch and read wrong data; normally each IC chip on a board have their own dedicated decoupling capacitor, to make sure they don't interfere with each other; look up that term on Wikipedia. Also try adding a 1-10k resistor from the data line at the turn table to ground; noise might be coming in from there. I think it's highly unlikely this is a firmware issue; not only am I an electronics nerd, I'm a programming nerd, and making an ID mistake in software is basically impossible even for a beginner, and I suspect they aren't beginners. Lack of filtering is very possible though even for good circuit designers, lots of things to miss accounting for.- And then I continued watching...
Thanks, Martin. I notice that your TT turns at a descent speed to each programmed stop. My Heljan 89121 moves slowly. Is there a speed adjustment procedure for this TT, please?
Hi, there is no speed setting or speed adjustment for this TT. The only thing to check is that the unit is totally free to rotate without brushing past anything, and that it is receiving all the power that it needs from your supply. There is not much else that you can change.