Troubleshooting

[Tony]

That's around 300mA so close enough. I've been working on the code to switch off the HV during display blanking. Do you have access to a pic programmer?.

[sean4star]

No, I don't...

How much do they run? Do you have any suggestions for model, etc? I've never done any programming or loading programs...is it very complicated?

[Tony]

You should be able to find a Pickit 3 for $40-45 or a Chinese clone for less, probably even with a ZIF socket adapter which will make programming much easier than connecting directly to the PCB.
Install MPlab (free from Microchip - the main reason I use them is the cheapness of dev tools. I bought a Freescale programmer to try out their devices as I used to program in 65/6800 years ago but their sotware is a silly price).
The code can be written, compiled and programmed from within the one program and IMO is very straightforward once you work out what does what....

[sean4star]

If I get the pickit3 do I need to get anything else special to connect to the pcb? Or is it just the pickit and the Mplab software?

Oh, and what can I look up to start learning how to program pic chips? Is there a certain programming language that is used?

[adminbear]

My kit is now working (minus the last Nixie which I messed up & am waiting on a replacement for). I've got it sitting on a piece of cardboard under my TV so I can sit and watch it. This evening it's ever continuing pattern of switching between temp & humidity changed and caught my eye. The three digits were counting down together... 999, 888, 777...222, 111 along with tube 4 changing through it's elements. When it finished it's countdown, it went back to it's normal operating mode. Is this some kind of Easter egg or a reset cycle or???

[Tony]

You'll need to make up a connecting lead, just a 5 pin .1" SIL plug to wire ends which can be soldered onto the board, or buy one with a ZIF socket adapter you can drop the IC into.

Plenty of info one the net but I wouldn't know the best place to start these days, been using these things for 20 years now

If I get the pickit3 do I need to get anything else special to connect to the pcb? Or is it just the pickit and the Mplab software?

Oh, and what can I look up to start learning how to program pic chips? Is there a certain programming language that is used?

[Tony]

It's a cathode cleaning sequence, it makes sure all the digits are used regularly to prevent 'poisoning'.

My kit is now working (minus the last Nixie which I messed up & am waiting on a replacement for). I've got it sitting on a piece of cardboard under my TV so I can sit and watch it. This evening it's ever continuing pattern of switching between temp & humidity changed and caught my eye. The three digits were counting down together... 999, 888, 777...222, 111 along with tube 4 changing through it's elements. When it finished it's countdown, it went back to it's normal operating mode. Is this some kind of Easter egg or a reset cycle or???

[adminbear]

Here's an oddity... when my unit is displaying humidity of "56%H", there's a flicker near one of the pins in the tube showing the "5". It's below the "base plate" inside the tube. However when it's showing "75.3 F", it's not there. Same tube, same number, just in the humidity display, there's something else showing up. Any idea??

Thanks,
jack

[Moharmate]

Hi i have just recently received my thermometer from think geek and I have assembled the PCB up to the first stage of testing and when I put my multimeter across R28 I get no reading set to the 1A scale. I have inspected the board for dry joints and bridges, its all good no bridges or dry joints found.

Here are pictures of the front and back of the pcb http://imgur.com/a/2zGXg

Thanks any help would be appreciated.

[Tony]

It could be slight leagage around the driver transistor, if there's anything conductve such as flux which may get slightly damp. Try cleaning any flux residue from under the driver transistors.

Here's an oddity... when my unit is displaying humidity of "56%H", there's a flicker near one of the pins in the tube showing the "5". It's below the "base plate" inside the tube. However when it's showing "75.3 F", it's not there. Same tube, same number, just in the humidity display, there's something else showing up. Any idea??

Thanks,
jack