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First of all if you're stuck please just email and ask, I'll do what I can to help.

If you're quite sure you are unable to finish your kit, if you have parts in the wrong place, damaged the PCB or just can't find out why it won't work and have given up, I will for a nominal fee plus postage costs repair or exchange your kit for a completed and working PCB.

As it's still probably going to be quite expensive due to the shipping cost only consider this as a last resort. I don't want anyone to be left with a useless kit so if you have no other option, it's there.

I have a clock with a V2 version of the pcb and have noticed a part of the instructions which says that if I want to use IN14 tubes I have to drill out two of the holes marked 2 and 3 I have 4 in-14 and 1in-19b tubes so can you confirm this is what I have to do before I go any further as I don't want to damage the board. Also in the photos with the instructions there is a resistor in position R34 which is not mentioned in the instructions is it necessary to put anything in this place?
Stephend

Yes you have IN-14 tubes, you can just use a link or low value resistor in place of R34 which is only used if you want to connect a GPS module. I would recommend doing so for future features.

Hi Tony I have finished assembling the clock and all seemed well until I tried to set the clock the right facing arrow on the centre tube works but I cannot get the left one to light up also the buzzer was working when I tested the clock but now does not I understand there is a knack to setting the clock so do you think I just have not got it yet or could I have done something constructing it? also is the led in position D17 on the board meant to light up as mine does not. Do you have any advice Thanks

IR problems are usually reflections or too much light reaching the sensor, swamping it. Make sure the heatshrink tube is sealed between the LED and case lid with no gaps.
D17 is an infra red LED and won't be visible.

Hi Tony,
I got a faint glow on the DP's when the tube display a 3, 4, 5 or 7.
This is due to the fact that when a low level is applied on D8 (or D16), it is supposed to switch off T11: But with the 0,6V voltage drop in D8 (or D16), the voltage between T11 base and emitter is around 0.6V instead of 0V : so T11 may be not completly switched off.

A solution is to replace T11 (MPSA42) by a N-Mosfet transistor (e.g. 2N7000) : with a 2N7000, the transistor will be really off with Vgs=0.6V. I did it : it works very well , no more faint glow in the DP's !!!
(the only difficulty is that T11 is very difficult to replace (very close to IC2 and the tube V5)

I hope that helps,

Regards

Hi Tony, I have a problem with the GPS:
- I connected a Neo-6 GPS unit (consumption is below 70mA) and at the first attempt, it worked well : the clock displayed the time synchronized with the GPS
- but, after powering down the clock and powering it up again (with the GPS connected), the clock started normally and after a few second 3 tubes went off and only two remained on displaying static digit. (with a high pitch noise...)
- i had to power off, waiting for the supercapa to discharge. And when I powered on again (without the GPS), the clock started correctly. (i have to reconfigure time, date etc... and after that, all functions were working)
- But, when I connected the GPS again: same behaviour: 3 tubes went off, two remained on.

After that I did some tests: I wanted to know if it is a hardware (consumption too high...) or a software issue
1- connect the GPS unit to my computer (via USB) and checked the TxD data with a oscilloscope: everything correct: I can see the TxD data transmitted with a 5V level
2- check the GPS unit with the UBlock associated software : everything correct, the GPS get a fix and transmit the position and the time correctly
3- Then I powered the GPS unit with my computer (USB) and connect to the clock only the GND and the TxD (I protected the TxD with a 1kohm in serie and 10kohm as pullup): I did this connection only after the GPS got a fix: everything worked: the clock synchronized with the GPS.
4- Then I did the same thing (powered the GPS with the computer and connect GND and TxD to the clock) but, I did the connection with a cold start of the GPS (no fix) : The clock started a few seconds and then went to the doomy mode: 3 tubes off, 2 remained on...

It seems not to be a harware issue: only the TxD and the GND are connected to the clock and I check the signal with the oscilloscope.
It is as if the microcontroller get lost when recieving data from the GPS that are not yet valid (empty frames because no fix yet...)

Did you face the same problem before?
do you have any clue?
I will dive into the source code but before I would like to know if you have any idea !

Could you post the latest version of the source code?

Thank you in advance for your support

Best regards

It may be a buffer overflow problem, I'll have a look as soon as I've caught up a bit here. It shouldn't happen as it checks the buffer pointer for a max value.

Hi Skyraider,
I have the same glowing decimal points problem as you, but on the cylinder clock, the digits that cause the problem are different, but they equate to the same output pins on the K155 (pins 10,11,13 & 14) which equates to input C on the K155 ie binary 0010, presumably there is some mapping in the software to change the sequence of the digits between yours and mine and standard.
Anyway, I think you are quite correct in your analysis, in which case an alternative fix would be to use a pair of schotky diodes in place of the two silicon diodes D8 D16 (on yours) D9 D10 (on mine), lower volt drop, so pulling the base down harder. These could even be soldered in parallel with the diodes in situe, so no need to desolder.
Regards,
Kevin.

Missed that post above - the faint glowing DPs are deliberate, they're supposed to look like 'flickering neons' on the cylinder clock but didn't work out so well on the V1. Just increase the value of R14, back to 270k as used in the earlier kits.