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[Rupes]

Hi.
I’ve built my DIY AstroEQ based on PCB and ICs sourced from Tom and components sourced from Farnell following the links in the parts list.

All looks OK but I’ve powered up (no motors connected yet) and something is not working.

Power light comes on.

USB light flashes indicating connection and the PC seems to recognise that something has connected but is unable to do firmware upgrades or establish operational comms with the AstroEQ as far as I can tell.

There’s no sign of life from the status LED. I’ve checked the LED itself and that’s OK. I’m wondering what simple checks I could carry out to help me diagnose the problem. I’ve had a good look at the soldering and have tidied up one or two connections but no improvement.

Thanks in advance for any help.

[TCWORLD]

Could you post a picture of the back on the PCB.

Also, what happens when you run the firmware update option with the config utility?

Did you connect +12V first before the USB connector?

[Rupes]

Hi Tom

Here are some pics of the back of the pcb.

Yes, I did connect power first then USB.

I have just tried running the firmware update but after about 10 minutes it eventually got to the upload failed screen.

[Rupes]

Another PCB pic from the other angle

[Rupes]

Firmware update failed

[TCWORLD]

Apologies for the delay.

That soldering looks pretty good.
I would check the ground of C15 which looks like it hasn't taken. The same goes for one side of R15 which may be an issue.

Might also be worth checking pin 15 of the RA motor driver - the ground looks like a bad joint, though that wouldn't affect programming.

If that doesn't help, the next check is to make sure all pins of the ATMega and PIC are correctly in the socket (sometimes they can fold over or miss). You could also try removing and reinserting just to be sure.

Let me know how it goes.

Kind Regards,
Tom.

[Rupes]

Hi Tom

Thanks for you help - I’m sure you have better things to do at this time of year.

I’ve checked and resoldered the connections for R15 and C15 and have removed and refitted the two chips - no folded legs.

Still no luck with the firmware upgraded - although I have noticed that sometimes it takes many minutes to go through the ten attempts/failures and sometimes it goes very quickly. Also it doesn’t always give the same failure message for each attempt. Not sure what this is telling us. I was fiddling with wires and pressing down on the chips when getting these mixed results.

[TCWORLD]

Hmm, not sure.

If you connect pins 10 and 12 of the PIC together and connect via a serial termial (e.g. PuTTY or similar), do you get data echoing back? That would rule out the PIC/USB as an issue, leaving just the ATMega.

[Rupes]

Hi Tom

Sorry for the long delay in coming back. 

I had given up on this project for a while.  However, whilst working on another electronics project I discovered that some of my packs of ebay resistors had been mis-labelled - the labels for 10R and 10k resistors were the wrong way round - so it turns out that (due to not checking the colours) I have merrily put three 10R resistors into my AstroEQ circuit instead of the 10K ones.  I have now removed the incorrect resistors and replaced with the correct sizes.

This has unfortunately not improved the results but I guess the first question is whether this mistake is likely to have damaged either of the chips?

I have downloaded PUTTY and had a go with this, following some instructions on the internet.  I think I have successfully opened up communication with the relevant COM port and have linked together pins 10 and 12 of the PIC but there is no sign of anything coming back.

Any further thoughts welcomed - perhaps I should order a new PIC/ATMEGA on the assumption that I've knackered the previous ones with my mis-resistoring?

[Rupes]

Hi again

I've come to the realisation that I shouldn't be messing around with electronics as I clearly can't manage the basics!

I was tidying up my many wires today and in the process I discovered that I've been powering my AstroEQ with a 5V power supply.

So I've tried it with a 12V supply and hey presto, it all works now!  I've gone through the firmware update and EEPROM updates and have made it to the Configuration Setup Page.  Now I can put it into its box and go shopping for a stepper motor for the next stage of this adventure.

Thanks for the support so far.  I'll keep plugging on with this and I may even have a fully operational system by the time the darker nights come around again!

[TCWORLD]

Hi,

Glad you've sorted it.

Kind Regards,
Tom